Re: [PATCH] mmc: dw_mmc: change to use recommended reset procedure

Ulf Hansson
2014-08-11T07:55:27Z

On 5 August 2014 03:19, Sonny Rao <sonnyrao@chromium.org> wrote:
> This patch changes the fifo reset code to follow the reset procedure
> outlined in the documentation of Synopsys Mobile storage host databook.
>
> Signed-off-by: Sonny Rao <sonnyrao@chromium.org>
> Signed-off-by: Yuvaraj Kumar C D <yuvaraj.cd@samsung.com>
> Acked-by: Seungwon Jeon <tgih.jun@samsung.com>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> [sonnyrao: fix compile for !CONFIG_MMC_DW_IDMAC case]

Thanks! Applied for next!

Kind regards
Uffe

> ---
> drivers/mmc/host/dw_mmc.c | 87 ++++++++++++++++++++++++++++++++++-------------
> drivers/mmc/host/dw_mmc.h | 5 +++
> 2 files changed, 69 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 1ac227c..39cf54f 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -111,8 +111,7 @@ static const u8 tuning_blk_pattern_8bit[] = {
> 0xff, 0x77, 0x77, 0xff, 0x77, 0xbb, 0xdd, 0xee,
> };
>
> -static inline bool dw_mci_fifo_reset(struct dw_mci *host);
> -static inline bool dw_mci_ctrl_all_reset(struct dw_mci *host);
> +static bool dw_mci_reset(struct dw_mci *host);
>
> #if defined(CONFIG_DEBUG_FS)
> static int dw_mci_req_show(struct seq_file *s, void *v)
> @@ -1235,7 +1234,7 @@ static int dw_mci_data_complete(struct dw_mci *host, struct mmc_data *data)
> * After an error, there may be data lingering
> * in the FIFO
> */
> - dw_mci_fifo_reset(host);
> + dw_mci_reset(host);
> } else {
> data->bytes_xfered = data->blocks * data->blksz;
> data->error = 0;
> @@ -1352,7 +1351,7 @@ static void dw_mci_tasklet_func(unsigned long priv)
>
> /* CMD error in data command */
> if (mrq->cmd->error && mrq->data)
> - dw_mci_fifo_reset(host);
> + dw_mci_reset(host);
>
> host->cmd = NULL;
> host->data = NULL;
> @@ -1963,14 +1962,8 @@ static void dw_mci_work_routine_card(struct work_struct *work)
> }
>
> /* Power down slot */
> - if (present == 0) {
> - /* Clear down the FIFO */
> - dw_mci_fifo_reset(host);
> -#ifdef CONFIG_MMC_DW_IDMAC
> - dw_mci_idmac_reset(host);
> -#endif
> -
> - }
> + if (present == 0)
> + dw_mci_reset(host);
>
> spin_unlock_bh(&host->lock);
>
> @@ -2208,8 +2201,11 @@ static bool dw_mci_ctrl_reset(struct dw_mci *host, u32 reset)
> return false;
> }
>
> -static inline bool dw_mci_fifo_reset(struct dw_mci *host)
> +static bool dw_mci_reset(struct dw_mci *host)
> {
> + u32 flags = SDMMC_CTRL_RESET | SDMMC_CTRL_FIFO_RESET;
> + bool ret = false;
> +
> /*
> * Reseting generates a block interrupt, hence setting
> * the scatter-gather pointer to NULL.
> @@ -2219,15 +2215,60 @@ static inline bool dw_mci_fifo_reset(struct dw_mci *host)
> host->sg = NULL;
> }
>
> - return dw_mci_ctrl_reset(host, SDMMC_CTRL_FIFO_RESET);
> -}
> + if (host->use_dma)
> + flags |= SDMMC_CTRL_DMA_RESET;
>
> -static inline bool dw_mci_ctrl_all_reset(struct dw_mci *host)
> -{
> - return dw_mci_ctrl_reset(host,
> - SDMMC_CTRL_FIFO_RESET |
> - SDMMC_CTRL_RESET |
> - SDMMC_CTRL_DMA_RESET);
> + if (dw_mci_ctrl_reset(host, flags)) {
> + /*
> + * In all cases we clear the RAWINTS register to clear any
> + * interrupts.
> + */
> + mci_writel(host, RINTSTS, 0xFFFFFFFF);
> +
> + /* if using dma we wait for dma_req to clear */
> + if (host->use_dma) {
> + unsigned long timeout = jiffies + msecs_to_jiffies(500);
> + u32 status;
> + do {
> + status = mci_readl(host, STATUS);
> + if (!(status & SDMMC_STATUS_DMA_REQ))
> + break;
> + cpu_relax();
> + } while (time_before(jiffies, timeout));
> +
> + if (status & SDMMC_STATUS_DMA_REQ) {
> + dev_err(host->dev,
> + "%s: Timeout waiting for dma_req to "
> + "clear during reset\n", __func__);
> + goto ciu_out;
> + }
> +
> + /* when using DMA next we reset the fifo again */
> + if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_FIFO_RESET))
> + goto ciu_out;
> + }
> + } else {
> + /* if the controller reset bit did clear, then set clock regs */
> + if (!(mci_readl(host, CTRL) & SDMMC_CTRL_RESET)) {
> + dev_err(host->dev, "%s: fifo/dma reset bits didn't "
> + "clear but ciu was reset, doing clock update\n",
> + __func__);
> + goto ciu_out;
> + }
> + }
> +
> +#if IS_ENABLED(CONFIG_MMC_DW_IDMAC)
> + /* It is also recommended that we reset and reprogram idmac */
> + dw_mci_idmac_reset(host);
> +#endif
> +
> + ret = true;
> +
> +ciu_out:
> + /* After a CTRL reset we need to have CIU set clock registers */
> + mci_send_cmd(host->cur_slot, SDMMC_CMD_UPD_CLK, 0);
> +
> + return ret;
> }
>
> #ifdef CONFIG_OF
> @@ -2425,7 +2466,7 @@ int dw_mci_probe(struct dw_mci *host)
> }
>
> /* Reset all blocks */
> - if (!dw_mci_ctrl_all_reset(host))
> + if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_ALL_RESET_FLAGS))
> return -ENODEV;
>
> host->dma_ops = host->pdata->dma_ops;
> @@ -2612,7 +2653,7 @@ int dw_mci_resume(struct dw_mci *host)
> }
> }
>
> - if (!dw_mci_ctrl_all_reset(host)) {
> + if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_ALL_RESET_FLAGS)) {
> ret = -ENODEV;
> return ret;
> }
> diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
> index 738fa24..08fd956 100644
> --- a/drivers/mmc/host/dw_mmc.h
> +++ b/drivers/mmc/host/dw_mmc.h
> @@ -129,6 +129,7 @@
> #define SDMMC_CMD_INDX(n) ((n) & 0x1F)
> /* Status register defines */
> #define SDMMC_GET_FCNT(x) (((x)>>17) & 0x1FFF)
> +#define SDMMC_STATUS_DMA_REQ BIT(31)
> /* FIFOTH register defines */
> #define SDMMC_SET_FIFOTH(m, r, t) (((m) & 0x7) << 28 | \
> ((r) & 0xFFF) << 16 | \
> @@ -150,6 +151,10 @@
> /* Card read threshold */
> #define SDMMC_SET_RD_THLD(v, x) (((v) & 0x1FFF) << 16 | (x))
>
> +/* All ctrl reset bits */
> +#define SDMMC_CTRL_ALL_RESET_FLAGS \
> + (SDMMC_CTRL_RESET | SDMMC_CTRL_FIFO_RESET | SDMMC_CTRL_DMA_RESET)
> +
> /* Register access macros */
> #define mci_readl(dev, reg) \
> __raw_readl((dev)->regs + SDMMC_##reg)
> --
> 1.8.3.2
>