Subject: [PATCH V2 1/2] Phy: Exynos: Add Exynos5250 sata phy driver

From: [email-masked] (Kishon Vijay Abraham I)
Date: Mon, 25 Nov 2013 11:55:17 +0530

Hi,

On Friday 22 November 2013 11:31 AM, Yuvaraj Kumar wrote:
> Any comments on this patch?
> 
> On Mon, Nov 11, 2013 at 2:02 PM, Yuvaraj Kumar C D <[email-masked]> wrote:
>> This patch adds the sata phy driver for Exynos5250.Exynos5250 sata
>> phy comprises of CMU and TRSV blocks which are of I2C register Map.
>> So this patch also adds a i2c client driver, which is used configure
>> the CMU and TRSV block of exynos5250 SATA PHY.
>>
>> This patch incorporates the generic phy framework to deal with sata
>> phy.
>>
>> This patch depends on the below patches
>>         [1].drivers: phy: add generic PHY framework
>>                 by Kishon Vijay Abraham I<[email-masked]>
>>         [2].ata: ahci_platform: Manage SATA PHY
>>                 by Roger Quadros <[email-masked]>
>> Changes from V1:
>>         1.Adapted to latest version of Generic PHY framework
>>         2.Removed exynos_sata_i2c_remove function.
>>
>> Signed-off-by: Yuvaraj Kumar C D <[email-masked]>
>> Signed-off-by: Girish K S <[email-masked]>
>> Signed-off-by: Vasanth Ananthan <[email-masked]>
>> ---
>>  drivers/phy/Kconfig               |    7 ++
>>  drivers/phy/Makefile              |    1 +
>>  drivers/phy/exynos5250_phy_i2c.c  |   43 +++++++
>>  drivers/phy/sata_phy_exynos5250.c |  245 +++++++++++++++++++++++++++++++++++++
>>  drivers/phy/sata_phy_exynos5250.h |   33 +++++
>>  5 files changed, 329 insertions(+)
>>  create mode 100644 drivers/phy/exynos5250_phy_i2c.c
>>  create mode 100644 drivers/phy/sata_phy_exynos5250.c
>>  create mode 100644 drivers/phy/sata_phy_exynos5250.h
>>
>> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
>> index 349bef2..8afd423 100644
>> --- a/drivers/phy/Kconfig
>> +++ b/drivers/phy/Kconfig
>> @@ -15,4 +15,11 @@ config GENERIC_PHY
>>           phy users can obtain reference to the PHY. All the users of this
>>           framework should select this config.
>>
>> +config EXYNOS5250_SATA_PHY
>> +       tristate "Exynos5250 Sata SerDes/PHY driver"
>> +       depends on GENERIC_PHY && SOC_EXYNOS5250

select GENERIC_PHY?
>> +       help
>> +         Support for Exynos5250 sata SerDes/Phy found on Samsung
>> +         SoCs.

checkpatch gives a warning if it doesn't have atleast 4 help lines :-s
>> +
>>  endmenu
>> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
>> index 9e9560f..824f47b 100644
>> --- a/drivers/phy/Makefile
>> +++ b/drivers/phy/Makefile
>> @@ -3,3 +3,4 @@
>>  #
>>
>>  obj-$(CONFIG_GENERIC_PHY)      += phy-core.o
>> +obj-$(CONFIG_EXYNOS5250_SATA_PHY)      += sata_phy_exynos5250.o exynos5250_phy_i2c.o
>> diff --git a/drivers/phy/exynos5250_phy_i2c.c b/drivers/phy/exynos5250_phy_i2c.c
>> new file mode 100644
>> index 0000000..752c8fe
>> --- /dev/null
>> +++ b/drivers/phy/exynos5250_phy_i2c.c
>> @@ -0,0 +1,43 @@
>> +/*
>> + * Copyright (C) 2013 Samsung Electronics Co.Ltd
>> + * Author:
>> + *     Yuvaraj C D <[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/i2c.h>
>> +#include <linux/module.h>
>> +#include "sata_phy_exynos5250.h"

arrange these headers in alphabetical order.. so it's easier to check if a
header has already been added while adding new headers.
>> +
>> +static int exynos_sata_i2c_probe(struct i2c_client *client,
>> +               const struct i2c_device_id *i2c_id)
>> +{
>> +       sataphy_attach_i2c_client(client);
>> +
>> +       dev_info(&client->adapter->dev,
>> +               "attached %s into sataphy i2c adapter successfully\n",
>> +               client->name);
>> +
>> +       return 0;
>> +}
>> +
>> +static const struct i2c_device_id phy_i2c_device_match[] = {
>> +       { "sata-phy-i2c", 0 },

pls use .compatible to assign compatible strings. Do you have dt documentation?
It should be *exynos,sata-phy-i2c*.
>> +};
>> +MODULE_DEVICE_TABLE(of, phy_i2c_device_match);
>> +
>> +struct i2c_driver sataphy_i2c_driver = {
>> +       .probe    = exynos_sata_i2c_probe,
>> +       .id_table = phy_i2c_device_match,
>> +       .driver   = {
>> +               .name = "sata-phy-i2c",
>> +               .owner = THIS_MODULE,
>> +               .of_match_table = (void *)phy_i2c_device_match,

use of_match_ptr here.
>> +               },
>> +};
>> diff --git a/drivers/phy/sata_phy_exynos5250.c b/drivers/phy/sata_phy_exynos5250.c
>> new file mode 100644
>> index 0000000..13f4ce0
>> --- /dev/null
>> +++ b/drivers/phy/sata_phy_exynos5250.c
>> @@ -0,0 +1,245 @@
>> +/*
>> + * Samsung SATA SerDes(PHY) driver
>> + *
>> + * Copyright (C) 2013 Samsung Electronics Co., Ltd.
>> + * Authors: Girish K S <[email-masked]>
>> + *         Yuvaraj Kumar C D <[email-masked]>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + */
>> +
>> +#include <linux/delay.h>
>> +#include <linux/io.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/of_address.h>
>> +#include <linux/phy/phy.h>
>> +#include <linux/i2c.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/spinlock.h>
>> +#include <linux/clk.h>
>> +#include "sata_phy_exynos5250.h"

arrange these in alphabetical order..
>> +
>> +static struct i2c_client *phy_i2c_client;

using globals :-s
how are you planning to handle when your SoC have multiple instances of this IP?
>> +
>> +struct exynos_sata_phy {
>> +       struct phy *phy;
>> +       struct clk *phyclk;
>> +       void __iomem *regs;
>> +       void __iomem *pmureg;

Tomasz mentioned in some other patch about using syscon interface for setting
pmureg. I think it's applicable here too.
>> +};
>> +
>> +static bool wait_for_reg_status(void __iomem *base, u32 reg, u32 checkbit,
>> +                               u32 status)
>> +{
>> +       unsigned long timeout = jiffies + usecs_to_jiffies(1000);
>> +       while (time_before(jiffies, timeout)) {
>> +               if ((readl(base + reg) & checkbit) == status)
>> +                       return true;
>> +       }
>> +       return false;
>> +}
>> +
>> +void sataphy_attach_i2c_client(struct i2c_client *sata_phy)

exynos_sata_phy_i2c_client?
>> +{
>> +       if (sata_phy)
>> +               phy_i2c_client = sata_phy;

you should return EPROBE_DEFER if sata_phy is NULL so that your i2c client will
try and attach with this driver again.
>> +}
>> +
>> +static int __set_phy_state(struct exynos_sata_phy *state, unsigned int on)
>> +{
>> +       u32 reg;
>> +
>> +       reg = readl(state->pmureg);
>> +       if (on)
>> +               reg |= EXYNOS_SATA_PHY_EN;
>> +       else
>> +               reg &= ~EXYNOS_SATA_PHY_EN;
>> +       writel(reg, state->pmureg);
>> +
>> +       return 0;
>> +}
>> +
>> +static int exynos_sata_phy_power_on(struct phy *phy)
>> +{
>> +       struct exynos_sata_phy *state = phy_get_drvdata(phy);
>> +
>> +       return __set_phy_state(state, 1);
>> +}
>> +
>> +static int exynos_sata_phy_power_off(struct phy *phy)
>> +{
>> +       struct exynos_sata_phy *state = phy_get_drvdata(phy);
>> +
>> +       return __set_phy_state(state, 0);
>> +}
>> +
>> +static int exynos_sataphy_parse_dt(struct device *dev,
>> +                               struct exynos_sata_phy *sata)
>> +{
exynos_sata_phy_parse_dt
>> +       struct device_node *np = dev->of_node;
>> +       struct device_node *sataphy_pmu;
>> +
>> +       sataphy_pmu = of_get_child_by_name(np, "sataphy-pmu");
>> +       if (!sataphy_pmu) {
>> +               dev_err(dev, "No PMU interface for sata-phy\n");
>> +               return -ENODEV;
>> +       }
>> +
>> +       sata->pmureg = of_iomap(sataphy_pmu, 0);
>> +       if (!sata->pmureg) {
>> +               dev_err(dev, "Can't get sata-phy pmu control register\n");
>> +               of_node_put(sataphy_pmu);
>> +               return -ENXIO;
>> +       }

As mentioned earlier you should use syscon interface for setting pmu registers.
>> +
>> +       of_node_put(sataphy_pmu);
>> +       return 0;
>> +}
>> +
>> +static int exynos_sata_phy_init(struct phy *phy)
>> +{
>> +       u32 val;
>> +       int ret = 0;
>> +       u8 buf[] = { 0x3A, 0x0B };
>> +       struct exynos_sata_phy *sata_phy = phy_get_drvdata(phy);
>> +
>> +       if (!phy_i2c_client)
>> +               return -EPROBE_DEFER;
>> +
>> +       writel(EXYNOS_SATA_PHY_EN, sata_phy->pmureg);
>> +
>> +       val = 0;
>> +       writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
>> +
>> +       val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
>> +       val |= 0xFF;
>> +       writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
>> +
>> +       val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
>> +       val |= LINK_RESET;
>> +       writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
>> +
>> +       val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
>> +       val |= RESET_CMN_RST_N;
>> +       writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
>> +       val = readl(sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
>> +       val &= ~PHCTRLM_REF_RATE;
>> +       writel(val, sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
>> +
>> +       /* High speed enable for Gen3 */
>> +       val = readl(sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
>> +       val |= PHCTRLM_HIGH_SPEED;
>> +       writel(val, sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
>> +
>> +       val |= CTRL0_P0_PHY_CALIBRATED_SEL | CTRL0_P0_PHY_CALIBRATED;
>> +       writel(val, sata_phy->regs + EXYNOS5_SATA_CTRL0);
>> +
>> +       writel(0x2, sata_phy->regs + EXYNOS5_SATA_MODE0);
>> +
>> +       ret = i2c_master_send(phy_i2c_client, buf, sizeof(buf));
>> +       if (ret < 0)
>> +               return -ENXIO;

huh.. Shouldn't this be done in your phy_i2c driver? Then you won't need the
attach i2c client stuff.
>> +
>> +       /* release cmu reset */
>> +       val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
>> +       val &= ~RESET_CMN_RST_N;
>> +       writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
>> +
>> +       val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
>> +       val |= RESET_CMN_RST_N;
>> +       writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
>> +
>> +       return (wait_for_reg_status(sata_phy->regs, EXYNOS5_SATA_PHSATA_STATM,
>> +               PHSTATM_PLL_LOCKED, 1)) ? 0 : -EINVAL;
>> +
>> +}
>> +
>> +static struct phy_ops exynos_sata_phy_ops = {
>> +       .init           = exynos_sata_phy_init,
>> +       .power_on       = exynos_sata_phy_power_on,
>> +       .power_off      = exynos_sata_phy_power_off,

you don't need exit callback that is complimentary to init?
>> +       .owner          = THIS_MODULE,
>> +};
>> +
>> +static int exynos_sata_phy_probe(struct platform_device *pdev)
>> +{
>> +       struct exynos_sata_phy *sata;
>> +       struct device *dev = &pdev->dev;
>> +       struct resource *res;
>> +       struct phy_provider *phy_provider;
>> +       int ret = 0;
>> +
>> +       sata = devm_kzalloc(dev, sizeof(*sata), GFP_KERNEL);
>> +       if (!sata)
>> +               return -ENOMEM;
>> +
>> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +
>> +       sata->regs = devm_ioremap_resource(dev, res);
>> +       if (IS_ERR(sata->regs))
>> +               return PTR_ERR(sata->regs);
>> +
>> +       dev_set_drvdata(dev, sata);
>> +
>> +       if (i2c_add_driver(&sataphy_i2c_driver)) {
>> +               dev_err(dev, "failed to register sataphy i2c driver\n");
>> +               return -ENOENT;
>> +       }
>> +
>> +       sata->phyclk = devm_clk_get(dev, "sata_phyctrl");
>> +       if (IS_ERR(sata->phyclk)) {
>> +               dev_err(dev, "failed to get clk for PHY\n");
>> +               return PTR_ERR(sata->phyclk);
>> +       }
>> +
>> +       ret = clk_prepare_enable(sata->phyclk);
>> +       if (ret < 0) {
>> +               dev_err(dev, "failed to enable source clk\n");
>> +               return ret;
>> +       }
>> +
>> +       if (dev->of_node) {
>> +               ret = exynos_sataphy_parse_dt(dev, sata);
>> +               if (ret)
>> +                       return ret;
>> +       }
>> +
>> +       phy_provider = devm_of_phy_provider_register(dev,
>> +                                       of_phy_simple_xlate);
>> +       if (IS_ERR(phy_provider))
>> +               return PTR_ERR(phy_provider);
>> +
>> +       sata->phy = devm_phy_create(dev, &exynos_sata_phy_ops, NULL);
>> +       if (IS_ERR(sata->phy)) {
>> +               dev_err(dev, "failed to create PHY\n");
>> +               return PTR_ERR(sata->phy);
>> +       }
>> +       phy_set_drvdata(sata->phy, sata);
>> +
>> +       return 0;
>> +}
>> +
>> +static const struct of_device_id exynos_sata_phy_of_match[] = {
>> +       { .compatible = "samsung,exynos5250-sata-phy" },
>> +       { },
>> +};
>> +MODULE_DEVICE_TABLE(of, exynos_sata_phy_of_match);
>> +
>> +static struct platform_driver exynos_sata_phy_driver = {
>> +       .probe  = exynos_sata_phy_probe,
>> +       .driver = {
>> +               .of_match_table = exynos_sata_phy_of_match,

use of_match_ptr..
>> +               .name  = "samsung,sata-phy",
>> +               .owner = THIS_MODULE,
>> +       }
>> +};
>> +module_platform_driver(exynos_sata_phy_driver);
>> +
>> +MODULE_DESCRIPTION("Samsung SerDes PHY driver");
>> +MODULE_LICENSE("GPL");

GPL v2?
>> +MODULE_AUTHOR("ks.giri <[email-masked]>");
>> +MODULE_AUTHOR("Yuvaraj C D <[email-masked]>");
>> diff --git a/drivers/phy/sata_phy_exynos5250.h b/drivers/phy/sata_phy_exynos5250.h
>> new file mode 100644
>> index 0000000..64e38a1
>> --- /dev/null
>> +++ b/drivers/phy/sata_phy_exynos5250.h
>> @@ -0,0 +1,33 @@
>> +/*
>> + *
>> + * Copyright (c) 2013 Samsung Electronics Co., Ltd.
>> + * Author:
>> + *     Yuvaraj Kumar C D<[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.
>> + */
>> +
>> +#define EXYNOS5_SATA_RESET             0x4
>> +#define EXYNOS5_SATA_MODE0              0x10
>> +#define EXYNOS5_SATA_CTRL0              0x14
>> +#define EXYNOS5_SATA_STAT0             0x18
>> +#define EXYNOS5_SATA_PHSATA_CTRLM       0xE0
>> +#define EXYNOS5_SATA_PHSATA_CTRL0       0xE4
>> +#define EXYNOS5_SATA_PHSATA_STATM       0xF0
>> +#define EXYNOS5_SATA_PHSTAT0            0xF4

use tabs instead of spaces.. looks like there is some alignment problem.

Thanks
Kishon