Subject: Re: [PATCH v6 3/4] spmi: mediatek: Add support for MT6873/8192

From: Hsin-hsiung Wang <[email-masked]>
Date: Sun, 14 Mar 2021 01:24:48 +0800

Hi,

On Mon, 2021-02-08 at 14:21 -0800, Stephen Boyd wrote:
> Quoting Hsin-Hsiung Wang (2021-02-06 21:19:13)
> > diff --git a/drivers/spmi/Kconfig b/drivers/spmi/Kconfig
> > index a53bad541f1a..418848840999 100644
> > --- a/drivers/spmi/Kconfig
> > +++ b/drivers/spmi/Kconfig
> > @@ -25,4 +25,13 @@ config SPMI_MSM_PMIC_ARB
> >           This is required for communicating with Qualcomm PMICs and
> >           other devices that have the SPMI interface.
> >  
> > +config SPMI_MTK_PMIF
> > +       tristate "Mediatek SPMI Controller (PMIC Arbiter)"
> > +       help
> > +         If you say yes to this option, support will be included for the
> > +         built-in SPMI PMIC Arbiter interface on Mediatek family
> > +         processors.
> > +
> > +         This is required for communicating with Mediatek PMICs and
> > +         other devices that have the SPMI interface.
> 
> Preferably add another newline here to unstick the 'endif'
> 

Thanks. I will update it in the next patch.

> >  endif
> > diff --git a/drivers/spmi/spmi-mtk-pmif.c b/drivers/spmi/spmi-mtk-pmif.c
> > new file mode 100644
> > index 000000000000..4ac4643f89f3
> > --- /dev/null
> > +++ b/drivers/spmi/spmi-mtk-pmif.c
> > @@ -0,0 +1,488 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +//
> > +// Copyright (c) 2021 MediaTek Inc.
> > +
> > +#include <linux/clk.h>
> > +#include <linux/iopoll.h>
> > +#include <linux/module.h>
> > +#include <linux/of_device.h>
> > +#include <linux/spmi.h>
> > +
> > +#define SWINF_IDLE     0x00
> > +#define SWINF_WFVLDCLR 0x06
> > +
> > +#define GET_SWINF(x)   (((x) >> 1) & 0x7)
> > +
> > +#define PMIF_CMD_REG_0         0
> > +#define PMIF_CMD_REG           1
> > +#define PMIF_CMD_EXT_REG       2
> > +#define PMIF_CMD_EXT_REG_LONG  3
> > +
> > +#define PMIF_DELAY_US   10
> > +#define PMIF_TIMEOUT_US (10 * 1000)
> > +
> > +#define PMIF_CHAN_OFFSET 0x5
> > +
> > +#define PMIF_MAX_CLKS  3
> > +
> > +#define SPMI_OP_ST_BUSY 1
> > +
> > +struct ch_reg {
> > +       u32 ch_sta;
> > +       u32 wdata;
> > +       u32 rdata;
> > +       u32 ch_send;
> > +       u32 ch_rdy;
> > +};
> > +
> > +struct pmif_data {
> > +       const u32       *regs;
> > +       const u32       *spmimst_regs;
> > +       u32     soc_chan;
> 
> Is this used?
> 

Yes.

> > +};
> > +
> > +struct pmif {
> > +       void __iomem    *base;
> > +       void __iomem    *spmimst_base;
> > +       raw_spinlock_t  lock;
> 
> Why is the spinlock raw? Is it used in hard irq handling?
> 

Thanks for the comment. After reviewing the code, I will remove it and
update it in the next patch.

> > +       struct ch_reg   chan;
> > +       struct clk_bulk_data clks[PMIF_MAX_CLKS];
> > +       u32 nclks;
> > +       const struct pmif_data *data;
> > +};
> > +
> > +static const char * const pmif_clock_names[] = {
> > +       "pmif_sys_ck", "pmif_tmr_ck", "spmimst_clk_mux",
> > +};
> > +
> > +enum pmif_regs {
> > +       PMIF_INIT_DONE,
> > +       PMIF_INF_EN,
> > +       PMIF_ARB_EN,
> > +       PMIF_CMDISSUE_EN,
> > +       PMIF_TIMER_CTRL,
> > +       PMIF_SPI_MODE_CTRL,
> > +       PMIF_IRQ_EVENT_EN_0,
> > +       PMIF_IRQ_FLAG_0,
> > +       PMIF_IRQ_CLR_0,
> > +       PMIF_IRQ_EVENT_EN_1,
> > +       PMIF_IRQ_FLAG_1,
> > +       PMIF_IRQ_CLR_1,
> > +       PMIF_IRQ_EVENT_EN_2,
> > +       PMIF_IRQ_FLAG_2,
> > +       PMIF_IRQ_CLR_2,
> > +       PMIF_IRQ_EVENT_EN_3,
> > +       PMIF_IRQ_FLAG_3,
> > +       PMIF_IRQ_CLR_3,
> > +       PMIF_IRQ_EVENT_EN_4,
> > +       PMIF_IRQ_FLAG_4,
> > +       PMIF_IRQ_CLR_4,
> > +       PMIF_WDT_EVENT_EN_0,
> > +       PMIF_WDT_FLAG_0,
> > +       PMIF_WDT_EVENT_EN_1,
> > +       PMIF_WDT_FLAG_1,
> > +       PMIF_SWINF_0_STA,
> > +       PMIF_SWINF_0_WDATA_31_0,
> > +       PMIF_SWINF_0_RDATA_31_0,
> > +       PMIF_SWINF_0_ACC,
> > +       PMIF_SWINF_0_VLD_CLR,
> > +       PMIF_SWINF_1_STA,
> > +       PMIF_SWINF_1_WDATA_31_0,
> > +       PMIF_SWINF_1_RDATA_31_0,
> > +       PMIF_SWINF_1_ACC,
> > +       PMIF_SWINF_1_VLD_CLR,
> > +       PMIF_SWINF_2_STA,
> > +       PMIF_SWINF_2_WDATA_31_0,
> > +       PMIF_SWINF_2_RDATA_31_0,
> > +       PMIF_SWINF_2_ACC,
> > +       PMIF_SWINF_2_VLD_CLR,
> > +       PMIF_SWINF_3_STA,
> > +       PMIF_SWINF_3_WDATA_31_0,
> > +       PMIF_SWINF_3_RDATA_31_0,
> > +       PMIF_SWINF_3_ACC,
> > +       PMIF_SWINF_3_VLD_CLR,
> > +};
> > +
> > +static const u32 mt6873_regs[] = {
> > +       [PMIF_INIT_DONE] =      0x0000,
> > +       [PMIF_INF_EN] =         0x0024,
> > +       [PMIF_ARB_EN] =         0x0150,
> > +       [PMIF_CMDISSUE_EN] =    0x03B4,
> > +       [PMIF_TIMER_CTRL] =     0x03E0,
> > +       [PMIF_SPI_MODE_CTRL] =  0x0400,
> > +       [PMIF_IRQ_EVENT_EN_0] = 0x0418,
> > +       [PMIF_IRQ_FLAG_0] =     0x0420,
> > +       [PMIF_IRQ_CLR_0] =      0x0424,
> > +       [PMIF_IRQ_EVENT_EN_1] = 0x0428,
> > +       [PMIF_IRQ_FLAG_1] =     0x0430,
> > +       [PMIF_IRQ_CLR_1] =      0x0434,
> > +       [PMIF_IRQ_EVENT_EN_2] = 0x0438,
> > +       [PMIF_IRQ_FLAG_2] =     0x0440,
> > +       [PMIF_IRQ_CLR_2] =      0x0444,
> > +       [PMIF_IRQ_EVENT_EN_3] = 0x0448,
> > +       [PMIF_IRQ_FLAG_3] =     0x0450,
> > +       [PMIF_IRQ_CLR_3] =      0x0454,
> > +       [PMIF_IRQ_EVENT_EN_4] = 0x0458,
> > +       [PMIF_IRQ_FLAG_4] =     0x0460,
> > +       [PMIF_IRQ_CLR_4] =      0x0464,
> > +       [PMIF_WDT_EVENT_EN_0] = 0x046C,
> > +       [PMIF_WDT_FLAG_0] =     0x0470,
> > +       [PMIF_WDT_EVENT_EN_1] = 0x0474,
> > +       [PMIF_WDT_FLAG_1] =     0x0478,
> > +       [PMIF_SWINF_0_ACC] =    0x0C00,
> > +       [PMIF_SWINF_0_WDATA_31_0] =     0x0C04,
> > +       [PMIF_SWINF_0_RDATA_31_0] =     0x0C14,
> > +       [PMIF_SWINF_0_VLD_CLR] =        0x0C24,
> > +       [PMIF_SWINF_0_STA] =    0x0C28,
> > +       [PMIF_SWINF_1_ACC] =    0x0C40,
> > +       [PMIF_SWINF_1_WDATA_31_0] =     0x0C44,
> > +       [PMIF_SWINF_1_RDATA_31_0] =     0x0C54,
> > +       [PMIF_SWINF_1_VLD_CLR] =        0x0C64,
> > +       [PMIF_SWINF_1_STA] =    0x0C68,
> > +       [PMIF_SWINF_2_ACC] =    0x0C80,
> > +       [PMIF_SWINF_2_WDATA_31_0] =     0x0C84,
> > +       [PMIF_SWINF_2_RDATA_31_0] =     0x0C94,
> > +       [PMIF_SWINF_2_VLD_CLR] =        0x0CA4,
> > +       [PMIF_SWINF_2_STA] =    0x0CA8,
> > +       [PMIF_SWINF_3_ACC] =    0x0CC0,
> > +       [PMIF_SWINF_3_WDATA_31_0] =     0x0CC4,
> > +       [PMIF_SWINF_3_RDATA_31_0] =     0x0CD4,
> > +       [PMIF_SWINF_3_VLD_CLR] =        0x0CE4,
> > +       [PMIF_SWINF_3_STA] =    0x0CE8,
> > +};
> > +
> > +enum spmi_regs {
> > +       SPMI_OP_ST_CTRL,
> > +       SPMI_GRP_ID_EN,
> > +       SPMI_OP_ST_STA,
> > +       SPMI_MST_SAMPL,
> > +       SPMI_MST_REQ_EN,
> > +       SPMI_REC_CTRL,
> > +       SPMI_REC0,
> > +       SPMI_REC1,
> > +       SPMI_REC2,
> > +       SPMI_REC3,
> > +       SPMI_REC4,
> > +       SPMI_MST_DBG,
> > +};
> > +
> > +static const u32 mt6873_spmi_regs[] = {
> 
> There's only one of these so far. Is there going to be a different
> register layout in the future? If we can avoid the indirection it would
> be ideal.
> 

Yes, we have other chips with different registers for spmi driver in the
feature.

> > +       [SPMI_OP_ST_CTRL] =     0x0000,
> > +       [SPMI_GRP_ID_EN] =      0x0004,
> > +       [SPMI_OP_ST_STA] =      0x0008,
> > +       [SPMI_MST_SAMPL] =      0x000c,
> > +       [SPMI_MST_REQ_EN] =     0x0010,
> > +       [SPMI_REC_CTRL] =       0x0040,
> > +       [SPMI_REC0] =           0x0044,
> > +       [SPMI_REC1] =           0x0048,
> > +       [SPMI_REC2] =           0x004c,
> > +       [SPMI_REC3] =           0x0050,
> > +       [SPMI_REC4] =           0x0054,
> > +       [SPMI_MST_DBG] =        0x00fc,
> > +};
> > +
> > +static u32 pmif_readl(struct pmif *arb, enum pmif_regs reg)
> > +{
> > +       return readl(arb->base + arb->data->regs[reg]);
> > +}
> > +
> > +static void pmif_writel(struct pmif *arb, u32 val, enum pmif_regs reg)
> > +{
> > +       writel(val, arb->base + arb->data->regs[reg]);
> > +}
> > +
> > +static void mtk_spmi_writel(struct pmif *arb, u32 val, enum spmi_regs reg)
> > +{
> > +       writel(val, arb->spmimst_base + arb->data->spmimst_regs[reg]);
> > +}
> > +
> > +static bool pmif_is_fsm_vldclr(struct pmif *arb)
> > +{
> > +       u32 reg_rdata;
> > +
> > +       reg_rdata = pmif_readl(arb, arb->chan.ch_sta);
> > +       return GET_SWINF(reg_rdata) == SWINF_WFVLDCLR;
> > +}
> > +
> > +static int pmif_arb_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid)
> > +{
> > +       struct pmif *arb = spmi_controller_get_drvdata(ctrl);
> > +       u32 rdata, cmd;
> > +       int ret;
> > +
> > +       /* Check for argument validation. */
> > +       if (sid & ~0xf) {
> > +               dev_err(&ctrl->dev, "exceed the max slv id\n");
> > +               return -EINVAL;
> > +       }
> > +
> > +       /* Check the opcode */
> > +       if (opc < SPMI_CMD_RESET || opc > SPMI_CMD_WAKEUP)
> > +               return -EINVAL;
> > +
> > +       cmd = opc - SPMI_CMD_RESET;
> > +
> > +       mtk_spmi_writel(arb, (cmd << 0x4) | sid, SPMI_OP_ST_CTRL);
> > +       ret = readl_poll_timeout_atomic(arb->spmimst_base + arb->data->spmimst_regs[SPMI_OP_ST_STA],
> > +                                       rdata, (rdata & SPMI_OP_ST_BUSY) == SPMI_OP_ST_BUSY,
> > +                                       PMIF_DELAY_US, PMIF_TIMEOUT_US);
> > +       if (ret < 0)
> > +               dev_err(&ctrl->dev, "timeout, err = %d\n", ret);
> > +
> > +       return ret;
> > +}
> > +
> > +static int pmif_spmi_read_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
> > +                             u16 addr, u8 *buf, size_t len)
> > +{
> > +       struct pmif *arb = spmi_controller_get_drvdata(ctrl);
> > +       struct ch_reg *inf_reg;
> > +       int ret;
> > +       u32 data, cmd;
> > +       unsigned long flags;
> > +
> > +       /* Check for argument validation. */
> > +       if (sid & ~0xf) {
> > +               dev_err(&ctrl->dev, "exceed the max slv id\n");
> > +               return -EINVAL;
> > +       }
> > +
> > +       if (len > 4) {
> > +               dev_err(&ctrl->dev, "pmif supports 1..4 bytes per trans, but:%zu requested", len);
> > +               return -EINVAL;
> > +       }
> > +
> > +       if (opc >= 0x60 && opc <= 0x7f)
> > +               opc = PMIF_CMD_REG;
> > +       else if ((opc >= 0x20 && opc <= 0x2f) || (opc >= 0x38 && opc <= 0x3f))
> > +               opc = PMIF_CMD_EXT_REG_LONG;
> > +       else
> > +               return -EINVAL;
> > +
> > +       raw_spin_lock_irqsave(&arb->lock, flags);
> > +
> > +       /* Wait for Software Interface FSM state to be IDLE. */
> > +       inf_reg = &arb->chan;
> > +       ret = readl_poll_timeout_atomic(arb->base + arb->data->regs[inf_reg->ch_sta],
> > +                                       data, GET_SWINF(data) == SWINF_IDLE,
> > +                                       PMIF_DELAY_US, PMIF_TIMEOUT_US);
> > +       if (ret < 0) {
> > +               /* set channel ready if the data has transferred */
> > +               if (pmif_is_fsm_vldclr(arb))
> > +                       pmif_writel(arb, 1, inf_reg->ch_rdy);
> > +               dev_err(&ctrl->dev, "failed to wait for SWINF_IDLE\n");
> > +               goto out;
> > +       }
> > +
> > +       /* Send the command. */
> > +       cmd = (opc << 30) | (sid << 24) | ((len - 1) << 16) | addr;
> > +       pmif_writel(arb, cmd, inf_reg->ch_send);
> > +
> > +       /*
> > +        * Wait for Software Interface FSM state to be WFVLDCLR,
> > +        * read the data and clear the valid flag.
> > +        */
> > +       ret = readl_poll_timeout_atomic(arb->base + arb->data->regs[inf_reg->ch_sta],
> > +                                       data, GET_SWINF(data) == SWINF_WFVLDCLR,
> > +                                       PMIF_DELAY_US, PMIF_TIMEOUT_US);
> > +       if (ret < 0) {
> > +               dev_err(&ctrl->dev, "failed to wait for SWINF_WFVLDCLR\n");
> > +               goto out;
> > +       }
> > +
> > +       data = pmif_readl(arb, inf_reg->rdata);
> > +       memcpy(buf, &data, len);
> > +       pmif_writel(arb, 1, inf_reg->ch_rdy);
> > +
> > +out:
> > +       raw_spin_unlock_irqrestore(&arb->lock, flags);
> > +       if (ret < 0)
> > +               return ret;
> > +
> > +       return 0;
> > +}
> > +
> > +static int pmif_spmi_write_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
> > +                              u16 addr, const u8 *buf, size_t len)
> > +{
> > +       struct pmif *arb = spmi_controller_get_drvdata(ctrl);
> > +       struct ch_reg *inf_reg;
> > +       int ret;
> > +       u32 data, cmd;
> > +       unsigned long flags;
> > +
> > +       /* Check for argument validation. */
> > +       if (sid & ~0xf) {
> > +               dev_err(&ctrl->dev, "exceed the max slv id\n");
> 
> Feels like something we should push up into the core framework instead
> of having each driver figure out.
> 

Thanks for the review.
After checking the framework, it already has the same check, so I will remove it in the next patch.

> > +               return -EINVAL;
> > +       }
> > +
> > +       if (len > 4) {
> > +               dev_err(&ctrl->dev, "pmif supports 1..4 bytes per trans, but:%zu requested", len);
> 
> Feels like something we should push up into the core framework instead
> of having each driver figure out.
> 

Thanks for the comment, it's our hw design, not for common driver. 

> > +               return -EINVAL;
> > +       }
> > +
> > +       /* Check the opcode */
> > +       if (opc >= 0x40 && opc <= 0x5F)
> > +               opc = PMIF_CMD_REG;
> > +       else if ((opc <= 0xF) || (opc >= 0x30 && opc <= 0x37))
> > +               opc = PMIF_CMD_EXT_REG_LONG;
> > +       else if (opc >= 0x80)
> > +               opc = PMIF_CMD_REG_0;
> > +       else
> > +               return -EINVAL;
> > +
> > +       raw_spin_lock_irqsave(&arb->lock, flags);
> > +
> > +       /* Wait for Software Interface FSM state to be IDLE. */
> > +       inf_reg = &arb->chan;
> > +       ret = readl_poll_timeout_atomic(arb->base + arb->data->regs[inf_reg->ch_sta],
> > +                                       data, GET_SWINF(data) == SWINF_IDLE,
> > +                                       PMIF_DELAY_US, PMIF_TIMEOUT_US);
> > +       if (ret < 0) {
> > +               /* set channel ready if the data has transferred */
> > +               if (pmif_is_fsm_vldclr(arb))
> > +                       pmif_writel(arb, 1, inf_reg->ch_rdy);
> > +               dev_err(&ctrl->dev, "failed to wait for SWINF_IDLE\n");
> > +               goto out;
> > +       }
> > +
> > +       /* Set the write data. */
> > +       memcpy(&data, buf, len);
> > +       pmif_writel(arb, data, inf_reg->wdata);
> > +
> > +       /* Send the command. */
> > +       cmd = (opc << 30) | BIT(29) | (sid << 24) | ((len - 1) << 16) | addr;
> > +       pmif_writel(arb, cmd, inf_reg->ch_send);
> 
> What is BIT 29? Is that special somehow?
> 

Bit 29 means write or read cmd.
1 for write and 0 for read. 

> > +
> > +out:
> > +       raw_spin_unlock_irqrestore(&arb->lock, flags);
> > +       if (ret < 0)
> > +               return ret;
> > +
> > +       return 0;
> > +}
> > +

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