Subject: [PATCH v10 03/15] ARM: sunxi: Add driver for SD/MMC hosts found on Allwinner sunxi SoCs

From: [email-masked] (Hans de Goede)
Date: Mon, 05 May 2014 15:10:12 +0200

Hi,

Thanks for the review, I will fix most of the issues you've
pointed out, but I've what I believe are good reasons for doing
things as they are done in some other places. For details see below.

Even if you agree with everything I've written below please send
me a reply along those lines, as I will be waiting for some of
the discussion items to be settled before doing a v11.

On 05/05/2014 02:41 PM, Ulf Hansson wrote:
> On 2 May 2014 17:57, Hans de Goede <[email-masked]> wrote:
>> From: David Lanzend?rfer <[email-masked]>
>>
>> The Allwinner sunxi mmc host uses dma in bus-master mode using a built-in
>> designware idmac controller, which is identical to the one found in the mmc-dw
>> hosts. However the rest of the host is not identical to mmc-dw, it deals with
>> sending stop commands in hardware which makes it significantly different
>> from the mmc-dw devices.
>>
>> HdG: Various cleanups and fixes.
>>
>> Signed-off-by: David Lanzend?rfer <[email-masked]>
>> Signed-off-by: Hans de Goede <[email-masked]>
>> ---
>>  .../devicetree/bindings/mmc/sunxi-mmc.txt          |   43 +
>>  drivers/mmc/host/Kconfig                           |    7 +
>>  drivers/mmc/host/Makefile                          |    2 +
>>  drivers/mmc/host/sunxi-mmc.c                       | 1125 ++++++++++++++++++++
>>  4 files changed, 1177 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/mmc/sunxi-mmc.txt
>>  create mode 100644 drivers/mmc/host/sunxi-mmc.c
>>
>> diff --git a/Documentation/devicetree/bindings/mmc/sunxi-mmc.txt b/Documentation/devicetree/bindings/mmc/sunxi-mmc.txt
>> new file mode 100644
>> index 0000000..91b3a34
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/mmc/sunxi-mmc.txt
>> @@ -0,0 +1,43 @@
>> +* Allwinner sunxi MMC controller
>> +
>> +The highspeed MMC host controller on Allwinner SoCs provides an interface
>> +for MMC, SD and SDIO types of memory cards.
>> +
>> +Supported maximum speeds are the ones of the eMMC standard 4.5 as well
>> +as the speed of SD standard 3.0.
>> +Absolute maximum transfer rate is 200MB/s
>> +
>> +Required properties:
>> + - compatible : "allwinner,sun4i-a10-mmc" or "allwinner,sun5i-a13-mmc"
>> + - reg : mmc controller base registers
>> + - clocks : a list with 2 phandle + clock specifier pairs
>> + - clock-names : must contain "ahb" and "mmc"
>> + - interrupts : mmc controller interrupt
>> +
>> +Optional properties:
>> + - resets : phandle + reset specifier pair
>> + - reset-names : must contain "ahb"
>> + - for cd, bus-width and additional generic mmc parameters
>> +   please refer to mmc.txt within this directory
>> +
>> +Examples:
>> +       - Within .dtsi:
>> +       mmc0: mmc at 01c0f000 {
>> +               compatible = "allwinner,sun5i-a13-mmc";
>> +               reg = <0x01c0f000 0x1000>;
>> +               clocks = <&ahb_gates 8>, <&mmc0_clk>;
>> +               clock-names = "ahb", "mod";
>> +               interrupts = <0 32 4>;
>> +               status = "disabled";
>> +       };
>> +
>> +       - Within dts:
>> +       mmc0: mmc at 01c0f000 {
>> +               pinctrl-names = "default", "default";
>> +               pinctrl-0 = <&mmc0_pins_a>;
>> +               pinctrl-1 = <&mmc0_cd_pin_reference_design>;
>> +               bus-width = <4>;
>> +               cd-gpios = <&pio 7 1 0>; /* PH1 */
>> +               cd-inverted;
>> +               status = "okay";
>> +       };
>> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
>> index 8aaf8c1..d50ac1c 100644
>> --- a/drivers/mmc/host/Kconfig
>> +++ b/drivers/mmc/host/Kconfig
>> @@ -694,3 +694,10 @@ config MMC_REALTEK_PCI
>>         help
>>           Say Y here to include driver code to support SD/MMC card interface
>>           of Realtek PCI-E card reader
>> +
>> +config MMC_SUNXI
>> +       tristate "Allwinner sunxi SD/MMC Host Controller support"
>> +       depends on ARCH_SUNXI
>> +       help
>> +         This selects support for the SD/MMC Host Controller on
>> +         Allwinner sunxi SoCs.
>> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
>> index 0c8aa5e..c706c0f 100644
>> --- a/drivers/mmc/host/Makefile
>> +++ b/drivers/mmc/host/Makefile
>> @@ -53,6 +53,8 @@ obj-$(CONFIG_MMC_WMT)         += wmt-sdmmc.o
>>
>>  obj-$(CONFIG_MMC_REALTEK_PCI)  += rtsx_pci_sdmmc.o
>>
>> +obj-$(CONFIG_MMC_SUNXI)                += sunxi-mmc.o
>> +
>>  obj-$(CONFIG_MMC_SDHCI_PLTFM)          += sdhci-pltfm.o
>>  obj-$(CONFIG_MMC_SDHCI_CNS3XXX)                += sdhci-cns3xxx.o
>>  obj-$(CONFIG_MMC_SDHCI_ESDHC_IMX)      += sdhci-esdhc-imx.o
>> diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c
>> new file mode 100644
>> index 0000000..2706b64
>> --- /dev/null
>> +++ b/drivers/mmc/host/sunxi-mmc.c
>> @@ -0,0 +1,1125 @@
>> +/*
>> + * Driver for sunxi SD/MMC host controllers
>> + * (C) Copyright 2007-2011 Reuuimlla Technology Co., Ltd.
>> + * (C) Copyright 2007-2011 Aaron Maoye <[email-masked]>
>> + * (C) Copyright 2013-2014 O2S GmbH <www.o2s.ch>
>> + * (C) Copyright 2013-2014 David Lanzend?rfer <[email-masked]>
>> + * (C) Copyright 2013-2014 Hans de Goede <[email-masked]>
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License as
>> + * published by the Free Software Foundation; either version 2 of
>> + * the License, or (at your option) any later version.
>> + */
>> +
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/io.h>
>> +#include <linux/device.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/delay.h>
>> +#include <linux/err.h>
>> +
>> +#include <linux/clk.h>
>> +#include <linux/clk-private.h>
>> +#include <linux/clk/sunxi.h>
>> +
>> +#include <linux/gpio.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/spinlock.h>
>> +#include <linux/scatterlist.h>
>> +#include <linux/dma-mapping.h>
>> +#include <linux/slab.h>
>> +#include <linux/regulator/consumer.h>
>> +#include <linux/reset.h>
>> +
>> +#include <linux/of_address.h>
>> +#include <linux/of_gpio.h>
>> +#include <linux/of_platform.h>
>> +
>> +#include <linux/mmc/host.h>
>> +#include <linux/mmc/sd.h>
>> +#include <linux/mmc/sdio.h>
>> +#include <linux/mmc/mmc.h>
>> +#include <linux/mmc/core.h>
>> +#include <linux/mmc/card.h>
>> +#include <linux/mmc/slot-gpio.h>
>> +
>> +/* register offset definitions */
>> +#define SDXC_REG_GCTRL (0x00) /* SMC Global Control Register */
>> +#define SDXC_REG_CLKCR (0x04) /* SMC Clock Control Register */
>> +#define SDXC_REG_TMOUT (0x08) /* SMC Time Out Register */
>> +#define SDXC_REG_WIDTH (0x0C) /* SMC Bus Width Register */
>> +#define SDXC_REG_BLKSZ (0x10) /* SMC Block Size Register */
>> +#define SDXC_REG_BCNTR (0x14) /* SMC Byte Count Register */
>> +#define SDXC_REG_CMDR  (0x18) /* SMC Command Register */
>> +#define SDXC_REG_CARG  (0x1C) /* SMC Argument Register */
>> +#define SDXC_REG_RESP0 (0x20) /* SMC Response Register 0 */
>> +#define SDXC_REG_RESP1 (0x24) /* SMC Response Register 1 */
>> +#define SDXC_REG_RESP2 (0x28) /* SMC Response Register 2 */
>> +#define SDXC_REG_RESP3 (0x2C) /* SMC Response Register 3 */
>> +#define SDXC_REG_IMASK (0x30) /* SMC Interrupt Mask Register */
>> +#define SDXC_REG_MISTA (0x34) /* SMC Masked Interrupt Status Register */
>> +#define SDXC_REG_RINTR (0x38) /* SMC Raw Interrupt Status Register */
>> +#define SDXC_REG_STAS  (0x3C) /* SMC Status Register */
>> +#define SDXC_REG_FTRGL (0x40) /* SMC FIFO Threshold Watermark Registe */
>> +#define SDXC_REG_FUNS  (0x44) /* SMC Function Select Register */
>> +#define SDXC_REG_CBCR  (0x48) /* SMC CIU Byte Count Register */
>> +#define SDXC_REG_BBCR  (0x4C) /* SMC BIU Byte Count Register */
>> +#define SDXC_REG_DBGC  (0x50) /* SMC Debug Enable Register */
>> +#define SDXC_REG_HWRST (0x78) /* SMC Card Hardware Reset for Register */
>> +#define SDXC_REG_DMAC  (0x80) /* SMC IDMAC Control Register */
>> +#define SDXC_REG_DLBA  (0x84) /* SMC IDMAC Descriptor List Base Addre */
>> +#define SDXC_REG_IDST  (0x88) /* SMC IDMAC Status Register */
>> +#define SDXC_REG_IDIE  (0x8C) /* SMC IDMAC Interrupt Enable Register */
>> +#define SDXC_REG_CHDA  (0x90)
>> +#define SDXC_REG_CBDA  (0x94)
>> +
>> +#define mci_readl(host, reg) \
>> +       readl((host)->reg_base + SDXC_##reg)
>> +#define mci_writel(host, reg, value) \
>> +       writel((value), (host)->reg_base + SDXC_##reg)
> 
> mci_readl|writel - why those function names? Wouldn't it make more
> sense if those relates to this driver's name instead somehow?

The driver used to be called sunxi-mci, it got renamed to
sunxi-mmc but this bit survived. I'll do a search replace
with something more suitable in the next version.

> 
>> +
>> +/* global control register bits */
>> +#define SDXC_SOFT_RESET                        BIT(0)
>> +#define SDXC_FIFO_RESET                        BIT(1)
>> +#define SDXC_DMA_RESET                 BIT(2)
>> +#define SDXC_INTERRUPT_ENABLE_BIT      BIT(4)
>> +#define SDXC_DMA_ENABLE_BIT            BIT(5)
>> +#define SDXC_DEBOUNCE_ENABLE_BIT       BIT(8)
>> +#define SDXC_POSEDGE_LATCH_DATA                BIT(9)
>> +#define SDXC_DDR_MODE                  BIT(10)
>> +#define SDXC_MEMORY_ACCESS_DONE                BIT(29)
>> +#define SDXC_ACCESS_DONE_DIRECT                BIT(30)
>> +#define SDXC_ACCESS_BY_AHB             BIT(31)
>> +#define SDXC_ACCESS_BY_DMA             (0 << 31)
>> +#define SDXC_HARDWARE_RESET \
>> +       (SDXC_SOFT_RESET | SDXC_FIFO_RESET | SDXC_DMA_RESET)
>> +
>> +/* clock control bits */
>> +#define SDXC_CARD_CLOCK_ON             BIT(16)
>> +#define SDXC_LOW_POWER_ON              BIT(17)
>> +
>> +/* bus width */
>> +#define SDXC_WIDTH1                    0
>> +#define SDXC_WIDTH4                    1
>> +#define SDXC_WIDTH8                    2
>> +
>> +/* smc command bits */
>> +#define SDXC_RESP_EXPIRE               BIT(6)
>> +#define SDXC_LONG_RESPONSE             BIT(7)
>> +#define SDXC_CHECK_RESPONSE_CRC                BIT(8)
>> +#define SDXC_DATA_EXPIRE               BIT(9)
>> +#define SDXC_WRITE                     BIT(10)
>> +#define SDXC_SEQUENCE_MODE             BIT(11)
>> +#define SDXC_SEND_AUTO_STOP            BIT(12)
>> +#define SDXC_WAIT_PRE_OVER             BIT(13)
>> +#define SDXC_STOP_ABORT_CMD            BIT(14)
>> +#define SDXC_SEND_INIT_SEQUENCE                BIT(15)
>> +#define SDXC_UPCLK_ONLY                        BIT(21)
>> +#define SDXC_READ_CEATA_DEV            BIT(22)
>> +#define SDXC_CCS_EXPIRE                        BIT(23)
>> +#define SDXC_ENABLE_BIT_BOOT           BIT(24)
>> +#define SDXC_ALT_BOOT_OPTIONS          BIT(25)
>> +#define SDXC_BOOT_ACK_EXPIRE           BIT(26)
>> +#define SDXC_BOOT_ABORT                        BIT(27)
>> +#define SDXC_VOLTAGE_SWITCH            BIT(28)
>> +#define SDXC_USE_HOLD_REGISTER         BIT(29)
>> +#define SDXC_START                     BIT(31)
>> +
>> +/* interrupt bits */
>> +#define SDXC_RESP_ERROR                        BIT(1)
>> +#define SDXC_COMMAND_DONE              BIT(2)
>> +#define SDXC_DATA_OVER                 BIT(3)
>> +#define SDXC_TX_DATA_REQUEST           BIT(4)
>> +#define SDXC_RX_DATA_REQUEST           BIT(5)
>> +#define SDXC_RESP_CRC_ERROR            BIT(6)
>> +#define SDXC_DATA_CRC_ERROR            BIT(7)
>> +#define SDXC_RESP_TIMEOUT              BIT(8)
>> +#define SDXC_DATA_TIMEOUT              BIT(9)
>> +#define SDXC_VOLTAGE_CHANGE_DONE       BIT(10)
>> +#define SDXC_FIFO_RUN_ERROR            BIT(11)
>> +#define SDXC_HARD_WARE_LOCKED          BIT(12)
>> +#define SDXC_START_BIT_ERROR           BIT(13)
>> +#define SDXC_AUTO_COMMAND_DONE         BIT(14)
>> +#define SDXC_END_BIT_ERROR             BIT(15)
>> +#define SDXC_SDIO_INTERRUPT            BIT(16)
>> +#define SDXC_CARD_INSERT               BIT(30)
>> +#define SDXC_CARD_REMOVE               BIT(31)
>> +#define SDXC_INTERRUPT_ERROR_BIT \
>> +       (SDXC_RESP_ERROR | SDXC_RESP_CRC_ERROR | SDXC_DATA_CRC_ERROR | \
>> +        SDXC_RESP_TIMEOUT | SDXC_DATA_TIMEOUT | SDXC_FIFO_RUN_ERROR | \
>> +        SDXC_HARD_WARE_LOCKED | SDXC_START_BIT_ERROR | SDXC_END_BIT_ERROR)
>> +#define SDXC_INTERRUPT_DONE_BIT \
>> +       (SDXC_AUTO_COMMAND_DONE | SDXC_DATA_OVER | \
>> +        SDXC_COMMAND_DONE | SDXC_VOLTAGE_CHANGE_DONE)
>> +
>> +/* status */
>> +#define SDXC_RXWL_FLAG                 BIT(0)
>> +#define SDXC_TXWL_FLAG                 BIT(1)
>> +#define SDXC_FIFO_EMPTY                        BIT(2)
>> +#define SDXC_FIFO_FULL                 BIT(3)
>> +#define SDXC_CARD_PRESENT              BIT(8)
>> +#define SDXC_CARD_DATA_BUSY            BIT(9)
>> +#define SDXC_DATA_FSM_BUSY             BIT(10)
>> +#define SDXC_DMA_REQUEST               BIT(31)
>> +#define SDXC_FIFO_SIZE                 16
>> +
>> +/* Function select */
>> +#define SDXC_CEATA_ON                  (0xceaa << 16)
>> +#define SDXC_SEND_IRQ_RESPONSE         BIT(0)
>> +#define SDXC_SDIO_READ_WAIT            BIT(1)
>> +#define SDXC_ABORT_READ_DATA           BIT(2)
>> +#define SDXC_SEND_CCSD                 BIT(8)
>> +#define SDXC_SEND_AUTO_STOPCCSD                BIT(9)
>> +#define SDXC_CEATA_DEV_IRQ_ENABLE      BIT(10)
>> +
>> +/* IDMA controller bus mod bit field */
>> +#define SDXC_IDMAC_SOFT_RESET          BIT(0)
>> +#define SDXC_IDMAC_FIX_BURST           BIT(1)
>> +#define SDXC_IDMAC_IDMA_ON             BIT(7)
>> +#define SDXC_IDMAC_REFETCH_DES         BIT(31)
>> +
>> +/* IDMA status bit field */
>> +#define SDXC_IDMAC_TRANSMIT_INTERRUPT          BIT(0)
>> +#define SDXC_IDMAC_RECEIVE_INTERRUPT           BIT(1)
>> +#define SDXC_IDMAC_FATAL_BUS_ERROR             BIT(2)
>> +#define SDXC_IDMAC_DESTINATION_INVALID         BIT(4)
>> +#define SDXC_IDMAC_CARD_ERROR_SUM              BIT(5)
>> +#define SDXC_IDMAC_NORMAL_INTERRUPT_SUM                BIT(8)
>> +#define SDXC_IDMAC_ABNORMAL_INTERRUPT_SUM      BIT(9)
>> +#define SDXC_IDMAC_HOST_ABORT_INTERRUPT                BIT(10)
>> +#define SDXC_IDMAC_IDLE                                (0 << 13)
>> +#define SDXC_IDMAC_SUSPEND                     (1 << 13)
>> +#define SDXC_IDMAC_DESC_READ                   (2 << 13)
>> +#define SDXC_IDMAC_DESC_CHECK                  (3 << 13)
>> +#define SDXC_IDMAC_READ_REQUEST_WAIT           (4 << 13)
>> +#define SDXC_IDMAC_WRITE_REQUEST_WAIT          (5 << 13)
>> +#define SDXC_IDMAC_READ                                (6 << 13)
>> +#define SDXC_IDMAC_WRITE                       (7 << 13)
>> +#define SDXC_IDMAC_DESC_CLOSE                  (8 << 13)
>> +
>> +/*
>> +* If the idma-des-size-bits of property is ie 13, bufsize bits are:
>> +*  Bits  0-12: buf1 size
>> +*  Bits 13-25: buf2 size
>> +*  Bits 26-31: not used
>> +* Since we only ever set buf1 size, we can simply store it directly.
>> +*/
>> +#define SDXC_IDMAC_DES0_DIC    BIT(1)  /* disable interrupt on completion */
>> +#define SDXC_IDMAC_DES0_LD     BIT(2)  /* last descriptor */
>> +#define SDXC_IDMAC_DES0_FD     BIT(3)  /* first descriptor */
>> +#define SDXC_IDMAC_DES0_CH     BIT(4)  /* chain mode */
>> +#define SDXC_IDMAC_DES0_ER     BIT(5)  /* end of ring */
>> +#define SDXC_IDMAC_DES0_CES    BIT(30) /* card error summary */
>> +#define SDXC_IDMAC_DES0_OWN    BIT(31) /* 1-idma owns it, 0-host owns it */
>> +
>> +struct sunxi_idma_des {
>> +       u32     config;
>> +       u32     buf_size;
>> +       u32     buf_addr_ptr1;
>> +       u32     buf_addr_ptr2;
>> +};
>> +
>> +struct sunxi_mmc_host {
>> +       struct mmc_host *mmc;
>> +       struct regulator *vmmc;
> 
> Instead of having a specific regulator for this driver, please use the
> mmc_regulator_get_supply API.

We cannot use mmc_regulator_get_supply because for the sunxi mmc controller
not only vqmmc but also vmmc itself is optional, and mmc_regulator_get_supply
calls devm_regulator_get rather then devm_regulator_get_optional for vmmc.

Using mmc_regulator_get_supply would lead to false postive errors being logged
on 99/100 boards.

> 
>> +       struct reset_control *reset;
>> +
>> +       /* IO mapping base */
>> +       void __iomem    *reg_base;
>> +
>> +       spinlock_t      lock;
>> +       struct tasklet_struct manual_stop_tasklet;
> 
> Any reason why you can't use a threaded IRQ handler instead of a tasklet?

AFAIK IRQ threaded handlers always have the highest priority. When
the manual_stop_tasklet runs we disable irqs and start polling to
recover from an error condition, which is nothing something I want
todo with the highest priority on the system.

> 
>> +
>> +       /* clock management */
>> +       struct clk      *clk_ahb;
>> +       struct clk      *clk_mod;
>> +
>> +       /* ios information */
>> +       u32             clk_mod_rate;
>> +       u32             bus_width;
>> +       u32             idma_des_size_bits;
>> +       u32             ddr;
>> +       u32             voltage_switching;
> 
> Are these ios informations actually needed. Can't at lease some of
> them be fetched from the mmc_host struct instead?

It is likely possible to drop some of these, I'll look into this for
the next version.

> 
>> +
>> +       /* irq */
>> +       int             irq;
>> +       u32             int_sum;
>> +       u32             sdio_imask;
>> +
>> +       /* flags */
>> +       bool            wait_dma;
>> +
>> +       dma_addr_t      sg_dma;
>> +       void            *sg_cpu;
>> +
>> +       struct mmc_request *mrq;
>> +       struct mmc_request *manual_stop_mrq;
>> +       u32             ferror;
>> +};
>> +
>> +static int sunxi_mmc_init_host(struct mmc_host *mmc)
>> +{
>> +       u32 rval;
>> +       struct sunxi_mmc_host *smc_host = mmc_priv(mmc);
>> +       int ret;
>> +
>> +       ret =  clk_prepare_enable(smc_host->clk_ahb);
>> +       if (ret) {
>> +               dev_err(mmc_dev(smc_host->mmc), "AHB clk err %d\n", ret);
>> +               return ret;
>> +       }
>> +
>> +       ret =  clk_prepare_enable(smc_host->clk_mod);
>> +       if (ret) {
>> +               dev_err(mmc_dev(smc_host->mmc), "MOD clk err %d\n", ret);
>> +               clk_disable_unprepare(smc_host->clk_ahb);
>> +               return ret;
>> +       }
>> +
>> +       if (smc_host->reset) {
>> +               ret = reset_control_deassert(smc_host->reset);
>> +               if (ret) {
>> +                       dev_err(mmc_dev(smc_host->mmc), "reset err %d\n", ret);
>> +                       clk_disable_unprepare(smc_host->clk_ahb);
>> +                       clk_disable_unprepare(smc_host->clk_mod);
>> +                       return ret;
>> +               }
>> +       }
>> +
>> +       /* reset controller */
>> +       rval = mci_readl(smc_host, REG_GCTRL);
>> +       rval |= SDXC_HARDWARE_RESET;
>> +       mci_writel(smc_host, REG_GCTRL, rval);
>> +
>> +       mci_writel(smc_host, REG_FTRGL, 0x20070008);
>> +       mci_writel(smc_host, REG_TMOUT, 0xffffffff);
>> +       mci_writel(smc_host, REG_IMASK, smc_host->sdio_imask);
>> +       mci_writel(smc_host, REG_RINTR, 0xffffffff);
>> +       mci_writel(smc_host, REG_DBGC, 0xdeb);
>> +       mci_writel(smc_host, REG_FUNS, SDXC_CEATA_ON);
>> +       mci_writel(smc_host, REG_DLBA, smc_host->sg_dma);
>> +
>> +       rval = mci_readl(smc_host, REG_GCTRL);
>> +       rval |= SDXC_INTERRUPT_ENABLE_BIT;
>> +       rval &= ~SDXC_ACCESS_DONE_DIRECT;
>> +       mci_writel(smc_host, REG_GCTRL, rval);
>> +
>> +       return 0;
>> +}
>> +
>> +static void sunxi_mmc_exit_host(struct sunxi_mmc_host *smc_host)
>> +{
>> +       mci_writel(smc_host, REG_GCTRL, SDXC_HARDWARE_RESET);
>> +
>> +       if (smc_host->reset)
>> +               reset_control_assert(smc_host->reset);
>> +
>> +       clk_disable_unprepare(smc_host->clk_ahb);
>> +       clk_disable_unprepare(smc_host->clk_mod);
>> +}
>> +
>> +/* /\* UHS-I Operation Modes */
>> +/*  * DS               25MHz   12.5MB/s        3.3V */
>> +/*  * HS               50MHz   25MB/s          3.3V */
>> +/*  * SDR12    25MHz   12.5MB/s        1.8V */
>> +/*  * SDR25    50MHz   25MB/s          1.8V */
>> +/*  * SDR50    100MHz  50MB/s          1.8V */
>> +/*  * SDR104   208MHz  104MB/s         1.8V */
>> +/*  * DDR50    50MHz   50MB/s          1.8V */
>> +/*  * MMC Operation Modes */
>> +/*  * DS               26MHz   26MB/s          3/1.8/1.2V */
>> +/*  * HS               52MHz   52MB/s          3/1.8/1.2V */
>> +/*  * HSDDR    52MHz   104MB/s         3/1.8/1.2V */
>> +/*  * HS200    200MHz  200MB/s         1.8/1.2V */
>> +/*  * */
>> +/*  * Spec. Timing */
>> +/*  * SD3.0 */
>> +/*  * Fcclk    Tcclk   Fsclk   Tsclk   Tis     Tih     odly  RTis     RTih */
>> +/*  * 400K     2.5us   24M     41ns    5ns     5ns     1     2209ns   41ns */
>> +/*  * 25M      40ns    600M    1.67ns  5ns     5ns     3     14.99ns  5.01ns */
>> +/*  * 50M      20ns    600M    1.67ns  6ns     2ns     3     14.99ns  5.01ns */
>> +/*  * 50MDDR   20ns    600M    1.67ns  6ns     0.8ns   2     6.67ns   3.33ns */
>> +/*  * 104M     9.6ns   600M    1.67ns  3ns     0.8ns   1     7.93ns   1.67ns */
>> +/*  * 208M     4.8ns   600M    1.67ns  1.4ns   0.8ns   1     3.33ns   1.67ns */
>> +
>> +/*  * 25M      40ns    300M    3.33ns  5ns     5ns     2     13.34ns   6.66ns */
>> +/*  * 50M      20ns    300M    3.33ns  6ns     2ns     2     13.34ns   6.66ns */
>> +/*  * 50MDDR   20ns    300M    3.33ns  6ns     0.8ns   1     6.67ns    3.33ns */
>> +/*  * 104M     9.6ns   300M    3.33ns  3ns     0.8ns   0     7.93ns    1.67ns */
>> +/*  * 208M     4.8ns   300M    3.33ns  1.4ns   0.8ns   0     3.13ns    1.67ns */
>> +
>> +/*  * eMMC4.5 */
>> +/*  * 400K     2.5us   24M     41ns    3ns     3ns     1     2209ns    41ns */
>> +/*  * 25M      40ns    600M    1.67ns  3ns     3ns     3     14.99ns   5.01ns */
>> +/*  * 50M      20ns    600M    1.67ns  3ns     3ns     3     14.99ns   5.01ns */
>> +/*  * 50MDDR   20ns    600M    1.67ns  2.5ns   2.5ns   2     6.67ns    3.33ns */
>> +/*  * 200M     5ns     600M    1.67ns  1.4ns   0.8ns   1     3.33ns    1.67ns */
>> +/*  *\/ */
> 
> It seems a bit silly to copy all the above data from the specs, I
> don't think it's needed.

I'll drop this.

> 
>> +
>> +static void sunxi_mmc_init_idma_des(struct sunxi_mmc_host *host,
>> +                                   struct mmc_data *data)
>> +{
>> +       struct sunxi_idma_des *pdes = (struct sunxi_idma_des *)host->sg_cpu;
>> +       struct sunxi_idma_des *pdes_pa = (struct sunxi_idma_des *)host->sg_dma;
>> +       int i, max_len = (1 << host->idma_des_size_bits);
>> +
>> +       for (i = 0; i < data->sg_len; i++) {
>> +               pdes[i].config = SDXC_IDMAC_DES0_CH | SDXC_IDMAC_DES0_OWN |
>> +                                SDXC_IDMAC_DES0_DIC;
>> +
>> +               if (data->sg[i].length == max_len)
>> +                       pdes[i].buf_size = 0; /* 0 == max_len */
>> +               else
>> +                       pdes[i].buf_size = data->sg[i].length;
>> +
>> +               pdes[i].buf_addr_ptr1 = sg_dma_address(&data->sg[i]);
>> +               pdes[i].buf_addr_ptr2 = (u32)&pdes_pa[i + 1];
>> +       }
>> +
>> +       pdes[0].config |= SDXC_IDMAC_DES0_FD;
>> +       pdes[i - 1].config = SDXC_IDMAC_DES0_OWN | SDXC_IDMAC_DES0_LD;
>> +
>> +       /*
>> +        * Avoid the io-store starting the idmac hitting io-mem before the
>> +        * descriptors hit the main-mem.
>> +        */
>> +       wmb();
>> +}
>> +
>> +static enum dma_data_direction sunxi_mmc_get_dma_dir(struct mmc_data *data)
>> +{
>> +       if (data->flags & MMC_DATA_WRITE)
>> +               return DMA_TO_DEVICE;
>> +       else
>> +               return DMA_FROM_DEVICE;
>> +}
>> +
>> +static int sunxi_mmc_map_dma(struct sunxi_mmc_host *smc_host,
>> +                            struct mmc_data *data)
>> +{
>> +       u32 i, dma_len;
>> +       struct scatterlist *sg;
>> +
>> +       dma_len = dma_map_sg(mmc_dev(smc_host->mmc), data->sg, data->sg_len,
>> +                            sunxi_mmc_get_dma_dir(data));
>> +       if (dma_len == 0) {
>> +               dev_err(mmc_dev(smc_host->mmc), "dma_map_sg failed\n");
>> +               return -ENOMEM;
>> +       }
>> +
>> +       for_each_sg(data->sg, sg, data->sg_len, i) {
>> +               if (sg->offset & 3 || sg->length & 3) {
>> +                       dev_err(mmc_dev(smc_host->mmc),
>> +                               "unaligned scatterlist: os %x length %d\n",
>> +                               sg->offset, sg->length);
>> +                       return -EINVAL;
>> +               }
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static void sunxi_mmc_start_dma(struct sunxi_mmc_host *smc_host,
>> +                               struct mmc_data *data)
>> +{
>> +       u32 rval;
>> +
>> +       sunxi_mmc_init_idma_des(smc_host, data);
>> +
>> +       rval = mci_readl(smc_host, REG_GCTRL);
>> +       rval |= SDXC_DMA_ENABLE_BIT;
>> +       mci_writel(smc_host, REG_GCTRL, rval);
>> +       rval |= SDXC_DMA_RESET;
>> +       mci_writel(smc_host, REG_GCTRL, rval);
>> +
>> +       mci_writel(smc_host, REG_DMAC, SDXC_IDMAC_SOFT_RESET);
>> +
>> +       if (!(data->flags & MMC_DATA_WRITE))
>> +               mci_writel(smc_host, REG_IDIE, SDXC_IDMAC_RECEIVE_INTERRUPT);
>> +
>> +       mci_writel(smc_host, REG_DMAC,
>> +                  SDXC_IDMAC_FIX_BURST | SDXC_IDMAC_IDMA_ON);
>> +}
>> +
>> +static void sunxi_mmc_send_manual_stop(struct sunxi_mmc_host *host,
>> +                                      struct mmc_request *req)
>> +{
>> +       u32 cmd_val = SDXC_START | SDXC_RESP_EXPIRE | SDXC_STOP_ABORT_CMD
>> +                       | SDXC_CHECK_RESPONSE_CRC | MMC_STOP_TRANSMISSION;
>> +       u32 ri = 0;
>> +       unsigned long expire = jiffies + msecs_to_jiffies(1000);
>> +
>> +       mci_writel(host, REG_CARG, 0);
>> +       mci_writel(host, REG_CMDR, cmd_val);
>> +
>> +       do {
>> +               ri = mci_readl(host, REG_RINTR);
>> +       } while (!(ri & (SDXC_COMMAND_DONE | SDXC_INTERRUPT_ERROR_BIT)) &&
>> +                time_before(jiffies, expire));
>> +
>> +       if (ri & SDXC_INTERRUPT_ERROR_BIT) {
>> +               dev_err(mmc_dev(host->mmc), "send stop command failed\n");
>> +               if (req->stop)
>> +                       req->stop->resp[0] = -ETIMEDOUT;
>> +       } else {
>> +               if (req->stop)
>> +                       req->stop->resp[0] = mci_readl(host, REG_RESP0);
>> +       }
>> +
>> +       mci_writel(host, REG_RINTR, 0xffff);
>> +}
>> +
>> +static void sunxi_mmc_dump_errinfo(struct sunxi_mmc_host *smc_host)
>> +{
>> +       struct mmc_command *cmd = smc_host->mrq->cmd;
>> +       struct mmc_data *data = smc_host->mrq->data;
>> +
>> +       /* For some cmds timeout is normal with sd/mmc cards */
>> +       if ((smc_host->int_sum & SDXC_INTERRUPT_ERROR_BIT) ==
>> +               SDXC_RESP_TIMEOUT && (cmd->opcode == SD_IO_SEND_OP_COND ||
>> +                                     cmd->opcode == SD_IO_RW_DIRECT))
>> +               return;
>> +
>> +       dev_err(mmc_dev(smc_host->mmc),
>> +               "smc %d err, cmd %d,%s%s%s%s%s%s%s%s%s%s !!\n",
>> +               smc_host->mmc->index, cmd->opcode,
>> +               data ? (data->flags & MMC_DATA_WRITE ? " WR" : " RD") : "",
>> +               smc_host->int_sum & SDXC_RESP_ERROR     ? " RE"     : "",
>> +               smc_host->int_sum & SDXC_RESP_CRC_ERROR  ? " RCE"    : "",
>> +               smc_host->int_sum & SDXC_DATA_CRC_ERROR  ? " DCE"    : "",
>> +               smc_host->int_sum & SDXC_RESP_TIMEOUT ? " RTO"    : "",
>> +               smc_host->int_sum & SDXC_DATA_TIMEOUT ? " DTO"    : "",
>> +               smc_host->int_sum & SDXC_FIFO_RUN_ERROR  ? " FE"     : "",
>> +               smc_host->int_sum & SDXC_HARD_WARE_LOCKED ? " HL"     : "",
>> +               smc_host->int_sum & SDXC_START_BIT_ERROR ? " SBE"    : "",
>> +               smc_host->int_sum & SDXC_END_BIT_ERROR   ? " EBE"    : ""
>> +               );
>> +}
>> +
>> +/* Called in interrupt context! */
>> +static int sunxi_mmc_finalize_request(struct sunxi_mmc_host *host)
>> +{
>> +       struct mmc_request *mrq = host->mrq;
>> +
>> +       mci_writel(host, REG_IMASK, host->sdio_imask);
>> +       mci_writel(host, REG_IDIE, 0);
>> +
>> +       if (host->int_sum & SDXC_INTERRUPT_ERROR_BIT) {
>> +               sunxi_mmc_dump_errinfo(host);
>> +               mrq->cmd->error = -ETIMEDOUT;
>> +
>> +               if (mrq->data)
>> +                       mrq->data->error = -ETIMEDOUT;
>> +
>> +               if (mrq->stop)
>> +                       mrq->stop->error = -ETIMEDOUT;
>> +       } else {
>> +               if (mrq->cmd->flags & MMC_RSP_136) {
>> +                       mrq->cmd->resp[0] = mci_readl(host, REG_RESP3);
>> +                       mrq->cmd->resp[1] = mci_readl(host, REG_RESP2);
>> +                       mrq->cmd->resp[2] = mci_readl(host, REG_RESP1);
>> +                       mrq->cmd->resp[3] = mci_readl(host, REG_RESP0);
>> +               } else {
>> +                       mrq->cmd->resp[0] = mci_readl(host, REG_RESP0);
>> +               }
>> +
>> +               if (mrq->data)
>> +                       mrq->data->bytes_xfered =
>> +                               mrq->data->blocks * mrq->data->blksz;
>> +       }
>> +
>> +       if (mrq->data) {
>> +               struct mmc_data *data = mrq->data;
>> +               u32 rval;
>> +
>> +               mci_writel(host, REG_IDST, 0x337);
>> +               mci_writel(host, REG_DMAC, 0);
>> +               rval = mci_readl(host, REG_GCTRL);
>> +               rval |= SDXC_DMA_RESET;
>> +               mci_writel(host, REG_GCTRL, rval);
>> +               rval &= ~SDXC_DMA_ENABLE_BIT;
>> +               mci_writel(host, REG_GCTRL, rval);
>> +               rval |= SDXC_FIFO_RESET;
>> +               mci_writel(host, REG_GCTRL, rval);
>> +               dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
>> +                                    sunxi_mmc_get_dma_dir(data));
>> +       }
>> +
>> +       mci_writel(host, REG_RINTR, 0xffff);
>> +
>> +       dev_dbg(mmc_dev(host->mmc), "req done, resp %08x %08x %08x %08x\n",
>> +               mrq->cmd->resp[0], mrq->cmd->resp[1],
>> +               mrq->cmd->resp[2], mrq->cmd->resp[3]);
>> +
>> +       host->mrq = NULL;
>> +       host->int_sum = 0;
>> +       host->wait_dma = false;
>> +
>> +       if (mrq->data && mrq->data->error) {
>> +               host->manual_stop_mrq = mrq;
>> +               tasklet_schedule(&host->manual_stop_tasklet);
>> +               return -EBUSY;
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static irqreturn_t sunxi_mmc_irq(int irq, void *dev_id)
>> +{
>> +       struct sunxi_mmc_host *host = dev_id;
>> +       struct mmc_request *mrq;
>> +       bool finalize = false;
>> +       bool complete = false;
>> +       bool sdio_int = false;
>> +       u32 msk_int;
>> +       u32 idma_int;
>> +
>> +       spin_lock(&host->lock);
>> +
>> +       idma_int  = mci_readl(host, REG_IDST);
>> +       msk_int   = mci_readl(host, REG_MISTA);
>> +
>> +       dev_dbg(mmc_dev(host->mmc), "irq: rq %p mi %08x idi %08x\n",
>> +               host->mrq, msk_int, idma_int);
>> +
>> +       mrq = host->mrq;
>> +       if (mrq) {
>> +               if (idma_int & SDXC_IDMAC_RECEIVE_INTERRUPT)
>> +                       host->wait_dma = false;
>> +
>> +               host->int_sum |= msk_int;
>> +
>> +               /* Wait for COMMAND_DONE on RESPONSE_TIMEOUT before finalize */
>> +               if ((host->int_sum & SDXC_RESP_TIMEOUT) &&
>> +                               !(host->int_sum & SDXC_COMMAND_DONE))
>> +                       mci_writel(host, REG_IMASK,
>> +                                  host->sdio_imask | SDXC_COMMAND_DONE);
>> +               /* Don't wait for dma on error */
>> +               else if (host->int_sum & SDXC_INTERRUPT_ERROR_BIT)
>> +                       finalize = true;
>> +               else if ((host->int_sum & SDXC_INTERRUPT_DONE_BIT) &&
>> +                               !host->wait_dma)
>> +                       finalize = true;
>> +       }
>> +
>> +       if (msk_int & SDXC_SDIO_INTERRUPT)
>> +               sdio_int = true;
>> +
>> +       mci_writel(host, REG_RINTR, msk_int);
>> +       mci_writel(host, REG_IDST, idma_int);
>> +
>> +       if (finalize) {
>> +               if (sunxi_mmc_finalize_request(host) == 0)
>> +                       complete = true;
>> +       }
>> +
>> +       spin_unlock(&host->lock);
>> +
>> +       if (complete)
>> +               mmc_request_done(host->mmc, mrq);
>> +
>> +       if (sdio_int)
>> +               mmc_signal_sdio_irq(host->mmc);
>> +
>> +       return IRQ_HANDLED;
>> +}
>> +
>> +static void sunxi_mmc_manual_stop_tasklet(unsigned long data)
>> +{
>> +       struct sunxi_mmc_host *host = (struct sunxi_mmc_host *) data;
>> +       struct mmc_request *mrq;
>> +       unsigned long iflags;
>> +
>> +       spin_lock_irqsave(&host->lock, iflags);
>> +       mrq = host->manual_stop_mrq;
>> +       spin_unlock_irqrestore(&host->lock, iflags);
>> +
>> +       if (!mrq) {
>> +               dev_err(mmc_dev(host->mmc), "no request for manual stop\n");
>> +               return;
>> +       }
>> +
>> +       dev_err(mmc_dev(host->mmc), "data error, sending stop command\n");
>> +       sunxi_mmc_send_manual_stop(host, mrq);
>> +
>> +       spin_lock_irqsave(&host->lock, iflags);
>> +       host->manual_stop_mrq = NULL;
>> +       spin_unlock_irqrestore(&host->lock, iflags);
>> +
>> +       mmc_request_done(host->mmc, mrq);
>> +}
>> +
>> +static void sunxi_mmc_oclk_onoff(struct sunxi_mmc_host *host, u32 oclk_en)
>> +{
>> +       unsigned long expire = jiffies + msecs_to_jiffies(2000);
>> +       u32 rval;
>> +
>> +       rval = mci_readl(host, REG_CLKCR);
>> +       rval &= ~(SDXC_CARD_CLOCK_ON | SDXC_LOW_POWER_ON);
>> +
>> +       if (oclk_en)
>> +               rval |= SDXC_CARD_CLOCK_ON;
>> +
>> +       mci_writel(host, REG_CLKCR, rval);
>> +
>> +       rval = SDXC_START | SDXC_UPCLK_ONLY | SDXC_WAIT_PRE_OVER;
>> +       if (host->voltage_switching)
>> +               rval |= SDXC_VOLTAGE_SWITCH;
>> +       mci_writel(host, REG_CMDR, rval);
>> +
>> +       do {
>> +               rval = mci_readl(host, REG_CMDR);
>> +       } while (time_before(jiffies, expire) && (rval & SDXC_START));
>> +
>> +       if (rval & SDXC_START) {
>> +               dev_err(mmc_dev(host->mmc), "fatal err update clk timeout\n");
>> +               host->ferror = 1;
>> +       }
>> +}
>> +
>> +static void sunxi_mmc_clk_set_rate(struct sunxi_mmc_host *smc_host,
>> +                                  unsigned int rate)
>> +{
>> +       u32 newrate, oclk_dly, rval, sclk_dly, src_clk;
>> +       struct clk_hw *hw = __clk_get_hw(smc_host->clk_mod);
>> +
>> +       newrate = clk_round_rate(smc_host->clk_mod, rate);
>> +       if (smc_host->clk_mod_rate == newrate) {
>> +               dev_dbg(mmc_dev(smc_host->mmc), "clk already %d, rounded %d\n",
>> +                       rate, newrate);
>> +               return;
>> +       }
>> +
>> +       dev_dbg(mmc_dev(smc_host->mmc), "setting clk to %d, rounded %d\n",
>> +               rate, newrate);
>> +
>> +       /* setting clock rate */
>> +       clk_set_rate(smc_host->clk_mod, newrate);
>> +       smc_host->clk_mod_rate = clk_get_rate(smc_host->clk_mod);
>> +       dev_dbg(mmc_dev(smc_host->mmc), "clk is now %d\n",
>> +               smc_host->clk_mod_rate);
>> +
>> +       sunxi_mmc_oclk_onoff(smc_host, 0);
>> +       /* clear internal divider */
>> +       rval = mci_readl(smc_host, REG_CLKCR);
>> +       rval &= ~0xff;
>> +       mci_writel(smc_host, REG_CLKCR, rval);
>> +
>> +       /* determine delays */
>> +       if (rate <= 400000) {
>> +               oclk_dly = 0;
>> +               sclk_dly = 7;
>> +       } else if (rate <= 25000000) {
>> +               oclk_dly = 0;
>> +               sclk_dly = 5;
>> +       } else if (rate <= 50000000) {
>> +               if (smc_host->ddr) {
>> +                       oclk_dly = 2;
>> +                       sclk_dly = 4;
>> +               } else {
>> +                       oclk_dly = 3;
>> +                       sclk_dly = 5;
>> +               }
>> +       } else {
>> +               /* rate > 50000000 */
>> +               oclk_dly = 2;
>> +               sclk_dly = 4;
>> +       }
>> +
>> +       src_clk = clk_get_rate(clk_get_parent(smc_host->clk_mod));
>> +       if (src_clk >= 300000000 && src_clk <= 400000000) {
>> +               if (oclk_dly)
>> +                       oclk_dly--;
>> +               if (sclk_dly)
>> +                       sclk_dly--;
>> +       }
>> +
>> +       clk_sunxi_mmc_phase_control(hw, sclk_dly, oclk_dly);
>> +       sunxi_mmc_oclk_onoff(smc_host, 1);
>> +
>> +       /* oclk_onoff sets various irq status bits, clear these */
>> +       mci_writel(smc_host, REG_RINTR,
>> +                  mci_readl(smc_host, REG_RINTR) & ~SDXC_SDIO_INTERRUPT);
>> +}
>> +
>> +static void sunxi_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>> +{
>> +       struct sunxi_mmc_host *host = mmc_priv(mmc);
>> +       u32 rval;
>> +       s32 err;
>> +
>> +       /* Set the power state */
>> +       switch (ios->power_mode) {
>> +       case MMC_POWER_ON:
>> +               break;
>> +
>> +       case MMC_POWER_UP:
>> +               if (!IS_ERR(host->vmmc)) {
>> +                       mmc_regulator_set_ocr(host->mmc, host->vmmc, ios->vdd);
>> +                       udelay(200);
>> +               }
>> +
>> +               err = sunxi_mmc_init_host(mmc);
> 
> So, sunxi_mmc_init_host() will ungate the clocks - but you shouldn't
> use ->set_ios() callback to implement power save.
> 
> Clocks should be ungated at ->probe() and gated at ->remove().
> 
> If fine grained power save is wanted, I advise you to rework the clock
> handling - and to build it upon runtime PM instead. Typically you
> would do these adaptations:
> 
> 1. Besides enabling the clocks at ->probe(), also enable runtime PM
> and use the runtime PM auto-suspend feature.
> 2. Add pm_runtime_get|put at the proper places in the driver.
> 3. Implement the runtime PM callbacks (suspend|resume) and do clock
> gating|ungating from there.
> 
> You may refer to drivers/mmc/host/mmci.c to get an example.

I'll just move the enable / disable to probe / remove for now.

>> +               if (err) {
>> +                       host->ferror = 1;
>> +                       return;
>> +               }
>> +
>> +               enable_irq(host->irq);
>> +
>> +               dev_dbg(mmc_dev(host->mmc), "power on!\n");
>> +               host->ferror = 0;
>> +               break;
>> +
>> +       case MMC_POWER_OFF:
>> +               dev_dbg(mmc_dev(host->mmc), "power off!\n");
>> +               disable_irq(host->irq);
>> +               sunxi_mmc_exit_host(host);
> 
> See comment above for sunxi_mmc_init_host().
> 
>> +               if (!IS_ERR(host->vmmc))
>> +                       mmc_regulator_set_ocr(host->mmc, host->vmmc, 0);
>> +
>> +               host->ferror = 0;
>> +               break;
>> +       }
>> +
>> +       /* set bus width */
>> +       switch (ios->bus_width) {
>> +       case MMC_BUS_WIDTH_1:
>> +               mci_writel(host, REG_WIDTH, SDXC_WIDTH1);
>> +               host->bus_width = 1;
>> +               break;
>> +       case MMC_BUS_WIDTH_4:
>> +               mci_writel(host, REG_WIDTH, SDXC_WIDTH4);
>> +               host->bus_width = 4;
>> +               break;
>> +       case MMC_BUS_WIDTH_8:
>> +               mci_writel(host, REG_WIDTH, SDXC_WIDTH8);
>> +               host->bus_width = 8;
>> +               break;
>> +       }
>> +
>> +       /* set ddr mode */
>> +       rval = mci_readl(host, REG_GCTRL);
>> +       if (ios->timing == MMC_TIMING_UHS_DDR50) {
>> +               rval |= SDXC_DDR_MODE;
>> +               host->ddr = 1;
>> +       } else {
>> +               rval &= ~SDXC_DDR_MODE;
>> +               host->ddr = 0;
>> +       }
>> +       mci_writel(host, REG_GCTRL, rval);
>> +
>> +       /* set up clock */
>> +       if (ios->clock && ios->power_mode) {
>> +               dev_dbg(mmc_dev(host->mmc), "ios->clock: %d\n", ios->clock);
>> +               sunxi_mmc_clk_set_rate(host, ios->clock);
>> +               usleep_range(50000, 55000);
> 
> Is those values for usleep really correct? I am not sure how many
> times we execute this path while detecting/powering the card, but
> quite a few.
> Detecting/powering the card is also done during each system
> suspend/resume cycle - thus this will heavily affect these cycles.

The problem is we've no docs, so this is all based on android code, the
android code has 2 drivers, lets call them the old and the new one.

This works is based on the new driver as that one was significantly
cleaner then the old driver. This bit comes directly from the new driver,
but it seems that the old driver has no delay at all. And clk_set_rate
already does a busy-wait waiting for the hardware to acknowledge the
clock rate change, so I think this is not really necessary. I'll run
some tests with it removed and if everything still works I'll drop it.

> 
>> +       }
>> +}
>> +
>> +static void sunxi_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
>> +{
>> +       struct sunxi_mmc_host *smc_host = mmc_priv(mmc);
>> +       unsigned long flags;
>> +       u32 imask;
>> +
>> +       spin_lock_irqsave(&smc_host->lock, flags);
>> +
>> +       imask = mci_readl(smc_host, REG_IMASK);
>> +       if (enable) {
>> +               smc_host->sdio_imask = SDXC_SDIO_INTERRUPT;
>> +               imask |= SDXC_SDIO_INTERRUPT;
>> +       } else {
>> +               smc_host->sdio_imask = 0;
>> +               imask &= ~SDXC_SDIO_INTERRUPT;
>> +       }
>> +       mci_writel(smc_host, REG_IMASK, imask);
>> +       spin_unlock_irqrestore(&smc_host->lock, flags);
>> +}
>> +
>> +static void sunxi_mmc_hw_reset(struct mmc_host *mmc)
>> +{
>> +       struct sunxi_mmc_host *smc_host = mmc_priv(mmc);
>> +       mci_writel(smc_host, REG_HWRST, 0);
>> +       udelay(10);
>> +       mci_writel(smc_host, REG_HWRST, 1);
>> +       udelay(300);
>> +}
>> +
>> +static void sunxi_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
>> +{
>> +       struct sunxi_mmc_host *host = mmc_priv(mmc);
>> +       struct mmc_command *cmd = mrq->cmd;
>> +       struct mmc_data *data = mrq->data;
>> +       unsigned long iflags;
>> +       u32 imask = SDXC_INTERRUPT_ERROR_BIT;
>> +       u32 cmd_val = SDXC_START | (cmd->opcode & 0x3f);
>> +       int ret;
>> +
>> +       if (!mmc_gpio_get_cd(mmc) || host->ferror) {
> 
> I wouldn't recommend to read the state of a gpio pin before you start
> serving requests, since it will add a latency for each of them.
> 
> I believe a better idea is to let the driver handle the errors that
> may occur during the transfer - and just report them upwards in the
> mmc stack. The mmc core should detect the card to be removed anyway.

Ok, I'll reemove this.

> 
>> +               dev_dbg(mmc_dev(host->mmc), "no medium present\n");
>> +               mrq->cmd->error = -ENOMEDIUM;
>> +               mmc_request_done(mmc, mrq);
>> +               return;
>> +       }
>> +
>> +       if (data) {
>> +               ret = sunxi_mmc_map_dma(host, data);
>> +               if (ret < 0) {
>> +                       dev_err(mmc_dev(host->mmc), "map DMA failed\n");
>> +                       cmd->error = ret;
>> +                       cmd->data->error = ret;
>> +                       mmc_request_done(host->mmc, mrq);
>> +                       return;
>> +               }
>> +       }
>> +
>> +       if (cmd->opcode == MMC_GO_IDLE_STATE) {
>> +               cmd_val |= SDXC_SEND_INIT_SEQUENCE;
>> +               imask |= SDXC_COMMAND_DONE;
> 
> This seems really strange! Please elaborate on why need specific
> handling of this CMD.

I've no clue, again no docs.

> 
>> +       }
>> +
>> +       if (cmd->opcode == SD_SWITCH_VOLTAGE) {
> 
> This won't work!
> 
> You must implement ->start_signal_voltage_switch() to follow spec and
> support UHS cards.
> Additionally your ->set_ios() shall support to gate the clock to the
> card, while the frequency is 0.
> 
> Optionally, you may implement ->card_busy().

Ok, lets just drop this for now. This is a left-over of the UHS
support in the android driver, which we've mostly removed as we've no UHS
capable boards to test with.

> 
>> +               cmd_val |= SDXC_VOLTAGE_SWITCH;
>> +               imask |= SDXC_VOLTAGE_CHANGE_DONE;
>> +               host->voltage_switching = 1;
>> +               sunxi_mmc_oclk_onoff(host, 1);
>> +       }
>> +
>> +       if (cmd->flags & MMC_RSP_PRESENT) {
>> +               cmd_val |= SDXC_RESP_EXPIRE;
>> +               if (cmd->flags & MMC_RSP_136)
>> +                       cmd_val |= SDXC_LONG_RESPONSE;
>> +               if (cmd->flags & MMC_RSP_CRC)
>> +                       cmd_val |= SDXC_CHECK_RESPONSE_CRC;
>> +
>> +               if ((cmd->flags & MMC_CMD_MASK) == MMC_CMD_ADTC) {
>> +                       cmd_val |= SDXC_DATA_EXPIRE | SDXC_WAIT_PRE_OVER;
>> +                       if (cmd->data->flags & MMC_DATA_STREAM) {
>> +                               imask |= SDXC_AUTO_COMMAND_DONE;
>> +                               cmd_val |= SDXC_SEQUENCE_MODE |
>> +                                          SDXC_SEND_AUTO_STOP;
>> +                       }
>> +
>> +                       if (cmd->data->stop) {
>> +                               imask |= SDXC_AUTO_COMMAND_DONE;
>> +                               cmd_val |= SDXC_SEND_AUTO_STOP;
>> +                       } else {
>> +                               imask |= SDXC_DATA_OVER;
>> +                       }
>> +
>> +                       if (cmd->data->flags & MMC_DATA_WRITE)
>> +                               cmd_val |= SDXC_WRITE;
>> +                       else
>> +                               host->wait_dma = true;
>> +               } else {
>> +                       imask |= SDXC_COMMAND_DONE;
>> +               }
>> +       } else {
>> +               imask |= SDXC_COMMAND_DONE;
>> +       }
>> +
>> +       dev_dbg(mmc_dev(host->mmc), "cmd %d(%08x) arg %x ie 0x%08x len %d\n",
>> +               cmd_val & 0x3f, cmd_val, cmd->arg, imask,
>> +               mrq->data ? mrq->data->blksz * mrq->data->blocks : 0);
>> +
>> +       spin_lock_irqsave(&host->lock, iflags);
>> +
>> +       if (host->mrq || host->manual_stop_mrq) {
>> +               spin_unlock_irqrestore(&host->lock, iflags);
>> +
>> +               if (data)
>> +                       dma_unmap_sg(mmc_dev(host->mmc), data->sg,
>> +                               data->sg_len, sunxi_mmc_get_dma_dir(data));
>> +
>> +               dev_err(mmc_dev(host->mmc), "request already pending\n");
>> +               mrq->cmd->error = -EBUSY;
>> +               mmc_request_done(host->mmc, mrq);
>> +               return;
>> +       }
>> +
>> +       if (data) {
>> +               mci_writel(host, REG_BLKSZ, data->blksz);
>> +               mci_writel(host, REG_BCNTR, data->blksz * data->blocks);
>> +               sunxi_mmc_start_dma(host, data);
>> +       }
>> +
>> +       host->mrq = mrq;
>> +       mci_writel(host, REG_IMASK, host->sdio_imask | imask);
>> +       mci_writel(host, REG_CARG, cmd->arg);
>> +       mci_writel(host, REG_CMDR, cmd_val);
>> +
>> +       spin_unlock_irqrestore(&host->lock, iflags);
>> +}
>> +
>> +static const struct of_device_id sunxi_mmc_of_match[] = {
>> +       { .compatible = "allwinner,sun4i-a10-mmc", },
>> +       { .compatible = "allwinner,sun5i-a13-mmc", },
>> +       { /* sentinel */ }
>> +};
>> +MODULE_DEVICE_TABLE(of, sunxi_mmc_of_match);
>> +
>> +static struct mmc_host_ops sunxi_mmc_ops = {
>> +       .request         = sunxi_mmc_request,
>> +       .set_ios         = sunxi_mmc_set_ios,
>> +       .get_ro          = mmc_gpio_get_ro,
>> +       .get_cd          = mmc_gpio_get_cd,
>> +       .enable_sdio_irq = sunxi_mmc_enable_sdio_irq,
>> +       .hw_reset        = sunxi_mmc_hw_reset,
>> +};
>> +
>> +static int sunxi_mmc_resource_request(struct sunxi_mmc_host *host,
>> +                                     struct platform_device *pdev)
>> +{
>> +       struct device_node *np = pdev->dev.of_node;
>> +       int ret;
>> +
>> +       if (of_device_is_compatible(np, "allwinner,sun4i-a10-mmc"))
>> +               host->idma_des_size_bits = 13;
>> +       else
>> +               host->idma_des_size_bits = 16;
>> +
>> +       host->vmmc = devm_regulator_get_optional(&pdev->dev, "vmmc");
>> +       if (IS_ERR(host->vmmc) && PTR_ERR(host->vmmc) == -EPROBE_DEFER)
>> +               return -EPROBE_DEFER;
>> +
>> +       host->reg_base = devm_ioremap_resource(&pdev->dev,
>> +                             platform_get_resource(pdev, IORESOURCE_MEM, 0));
>> +       if (IS_ERR(host->reg_base))
>> +               return PTR_ERR(host->reg_base);
>> +
>> +       host->clk_ahb = devm_clk_get(&pdev->dev, "ahb");
>> +       if (IS_ERR(host->clk_ahb)) {
>> +               dev_err(&pdev->dev, "Could not get ahb clock\n");
>> +               return PTR_ERR(host->clk_ahb);
>> +       }
>> +
>> +       host->clk_mod = devm_clk_get(&pdev->dev, "mmc");
>> +       if (IS_ERR(host->clk_mod)) {
>> +               dev_err(&pdev->dev, "Could not get mod clock\n");
>> +               return PTR_ERR(host->clk_mod);
>> +       }
>> +
>> +       host->reset = devm_reset_control_get(&pdev->dev, "ahb");
>> +       if (IS_ERR(host->reset))
>> +               host->reset = NULL; /* Having a reset controller is optional */
>> +
>> +       /*
>> +        * Sometimes the controller asserts the irq on boot for some reason,
>> +        * and since it is not clocked there is no way to clear it. So make
>> +        * sure the controller is in a sane state before enabling irqs.
>> +        */
>> +       ret = sunxi_mmc_init_host(host->mmc);
>> +       if (ret)
>> +               return ret;
>> +
>> +       host->irq = platform_get_irq(pdev, 0);
>> +       ret = devm_request_irq(&pdev->dev, host->irq, sunxi_mmc_irq, 0,
>> +                              "sunxi-mmc", host);
>> +       if (ret == 0)
>> +               disable_irq(host->irq);
>> +
>> +       /* And disable the controller again */
>> +       sunxi_mmc_exit_host(host);
>> +
>> +       return ret;
>> +}
>> +
>> +static int sunxi_mmc_probe(struct platform_device *pdev)
>> +{
>> +       struct sunxi_mmc_host *host;
>> +       struct mmc_host *mmc;
>> +       int ret;
>> +
>> +       mmc = mmc_alloc_host(sizeof(struct sunxi_mmc_host), &pdev->dev);
>> +       if (!mmc) {
>> +               dev_err(&pdev->dev, "mmc alloc host failed\n");
>> +               return -ENOMEM;
>> +       }
>> +
>> +       host = mmc_priv(mmc);
>> +       host->mmc = mmc;
>> +       spin_lock_init(&host->lock);
>> +       tasklet_init(&host->manual_stop_tasklet,
>> +                    sunxi_mmc_manual_stop_tasklet, (unsigned long)host);
>> +
>> +       ret = sunxi_mmc_resource_request(host, pdev);
>> +       if (ret)
>> +               goto error_free_host;
>> +
>> +       host->sg_cpu = dma_alloc_coherent(&pdev->dev, PAGE_SIZE,
>> +                                         &host->sg_dma, GFP_KERNEL);
>> +       if (!host->sg_cpu) {
>> +               dev_err(&pdev->dev, "Failed to allocate DMA descriptor mem\n");
>> +               ret = -ENOMEM;
>> +               goto error_free_host;
>> +       }
>> +
>> +       mmc->ops                = &sunxi_mmc_ops;
>> +       mmc->max_blk_count      = 8192;
>> +       mmc->max_blk_size       = 4096;
>> +       mmc->max_segs           = PAGE_SIZE / sizeof(struct sunxi_idma_des);
>> +       mmc->max_seg_size       = (1 << host->idma_des_size_bits);
>> +       mmc->max_req_size       = mmc->max_seg_size * mmc->max_segs;
>> +       /* 400kHz ~ 50MHz */
>> +       mmc->f_min              =   400000;
>> +       mmc->f_max              = 50000000;
>> +       /* available voltages */
>> +       if (!IS_ERR(host->vmmc))
>> +               mmc->ocr_avail = mmc_regulator_get_ocrmask(host->vmmc);
>> +       else
>> +               mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
>> +
>> +       mmc->caps |= MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED;
>> +       mmc->caps2 |= MMC_CAP2_NO_PRESCAN_POWERUP;
> 
> Are you sure you can enable this cap for all hosts/cards?

No, I'm not. I'll drop this, thanks!

> There are potential of breaking eMMC devices which has been powered
> during boot and unless you can fully reset/power cycle them.
> 
>> +
>> +       ret = mmc_of_parse(mmc);
>> +       if (ret)
>> +               goto error_free_dma;
>> +
>> +       ret = mmc_add_host(mmc);
>> +       if (ret)
>> +               goto error_free_dma;
>> +
>> +       dev_info(&pdev->dev, "base:0x%p irq:%u\n", host->reg_base, host->irq);
>> +       platform_set_drvdata(pdev, mmc);
>> +       return 0;
>> +
>> +error_free_dma:
>> +       dma_free_coherent(&pdev->dev, PAGE_SIZE, host->sg_cpu, host->sg_dma);
>> +error_free_host:
>> +       mmc_free_host(mmc);
>> +       return ret;
>> +}
>> +
>> +static int sunxi_mmc_remove(struct platform_device *pdev)
>> +{
>> +       struct mmc_host *mmc = platform_get_drvdata(pdev);
>> +       struct sunxi_mmc_host *host = mmc_priv(mmc);
>> +
>> +       mmc_remove_host(mmc);
>> +       sunxi_mmc_exit_host(host);
>> +       tasklet_disable(&host->manual_stop_tasklet);
>> +       dma_free_coherent(&pdev->dev, PAGE_SIZE, host->sg_cpu, host->sg_dma);
>> +       mmc_free_host(mmc);
>> +
>> +       return 0;
>> +}
>> +
>> +static struct platform_driver sunxi_mmc_driver = {
>> +       .driver = {
>> +               .name   = "sunxi-mmc",
>> +               .owner  = THIS_MODULE,
>> +               .of_match_table = of_match_ptr(sunxi_mmc_of_match),
>> +       },
>> +       .probe          = sunxi_mmc_probe,
>> +       .remove         = sunxi_mmc_remove,
>> +};
>> +module_platform_driver(sunxi_mmc_driver);
>> +
>> +MODULE_DESCRIPTION("Allwinner's SD/MMC Card Controller Driver");
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_AUTHOR("David Lanzend?rfer <[email-masked]>");
>> +MODULE_ALIAS("platform:sunxi-mmc");
>> --
>> 1.9.0

Regards,

Hans