Re: [PATCH 3/4] mmc: mediatek: Add tune support

Ulf Hansson
2015-10-14T10:05:21Z

On 13 October 2015 at 11:37, Chaotian Jing <chaotian.jing-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org> wrote:
> Add CMD19/CMD21 support for EMMC/SD/SDIO tuning
> Add HS400 mode support
>
> Signed-off-by: Chaotian Jing <chaotian.jing-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> ---
> drivers/mmc/host/mtk-sd.c | 359 ++++++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 332 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
> index b2e89d3..f12a50a 100644
> --- a/drivers/mmc/host/mtk-sd.c
> +++ b/drivers/mmc/host/mtk-sd.c
> @@ -26,6 +26,7 @@
> #include <linux/pm.h>
> #include <linux/pm_runtime.h>
> #include <linux/regulator/consumer.h>
> +#include <linux/slab.h>
> #include <linux/spinlock.h>
>
> #include <linux/mmc/card.h>
> @@ -64,6 +65,7 @@
> #define SDC_RESP2 0x48
> #define SDC_RESP3 0x4c
> #define SDC_BLK_NUM 0x50
> +#define EMMC_IOCON 0x7c
> #define SDC_ACMD_RESP 0x80
> #define MSDC_DMA_SA 0x90
> #define MSDC_DMA_CTRL 0x98
> @@ -71,6 +73,8 @@
> #define MSDC_PATCH_BIT 0xb0
> #define MSDC_PATCH_BIT1 0xb4
> #define MSDC_PAD_TUNE 0xec
> +#define PAD_DS_TUNE 0x188
> +#define EMMC50_CFG0 0x208
>
> /*--------------------------------------------------------------------------*/
> /* Register Mask */
> @@ -87,6 +91,7 @@
> #define MSDC_CFG_CKSTB (0x1 << 7) /* R */
> #define MSDC_CFG_CKDIV (0xff << 8) /* RW */
> #define MSDC_CFG_CKMOD (0x3 << 16) /* RW */
> +#define MSDC_CFG_HS400_CK_MODE (0x1 << 18) /* RW */
>
> /* MSDC_IOCON mask */
> #define MSDC_IOCON_SDR104CKS (0x1 << 0) /* RW */
> @@ -204,6 +209,17 @@
> #define MSDC_PATCH_BIT_SPCPUSH (0x1 << 29) /* RW */
> #define MSDC_PATCH_BIT_DECRCTMO (0x1 << 30) /* RW */
>
> +#define MSDC_PAD_TUNE_DATRRDLY (0x1f << 8) /* RW */
> +#define MSDC_PAD_TUNE_CMDRDLY (0x1f << 16) /* RW */
> +
> +#define PAD_DS_TUNE_DLY1 (0x1f << 2) /* RW */
> +#define PAD_DS_TUNE_DLY2 (0x1f << 7) /* RW */
> +#define PAD_DS_TUNE_DLY3 (0x1f << 12) /* RW */
> +
> +#define EMMC50_CFG_PADCMD_LATCHCK (0x1 << 0) /* RW */
> +#define EMMC50_CFG_CRCSTS_EDGE (0x1 << 3) /* RW */
> +#define EMMC50_CFG_CFCSTS_SEL (0x1 << 4) /* RW */
> +
> #define REQ_CMD_EIO (0x1 << 0)
> #define REQ_CMD_TMO (0x1 << 1)
> #define REQ_DAT_ERR (0x1 << 2)
> @@ -219,6 +235,7 @@
> #define CMD_TIMEOUT (HZ/10 * 5) /* 100ms x5 */
> #define DAT_TIMEOUT (HZ * 5) /* 1000ms x5 */
>
> +#define DELAY_MAX 32 /* PAD dalay cells */

/s/dalay/delay

Can we have some more explaination around this define. Perhaps a more
self-explaining name would be enough.-

> /*--------------------------------------------------------------------------*/
> /* Descriptor Structure */
> /*--------------------------------------------------------------------------*/
> @@ -265,6 +282,14 @@ struct msdc_save_para {
> u32 pad_tune;
> u32 patch_bit0;
> u32 patch_bit1;
> + u32 pad_ds_tune;
> + u32 emmc50_cfg0;
> +};
> +
> +struct msdc_delay_phase {
> + u8 maxlen;
> + u8 start;
> + u8 final_phase;
> };
>
> struct msdc_host {
> @@ -293,12 +318,15 @@ struct msdc_host {
> int irq; /* host interrupt */
>
> struct clk *src_clk; /* msdc source clock */
> + struct clk *src_clk_parent; /* src_clk's parent */
> + struct clk *hs400_src; /* 400Mhz source clock */

Hmm, so you need to control the upper level clocks. Can you elaborate
on why this is needed?

> struct clk *h_clk; /* msdc h_clk */
> u32 mclk; /* mmc subsystem clock frequency */
> u32 src_clk_freq; /* source clock frequency */
> u32 sclk; /* SD/MS bus clock frequency */
> - bool ddr;
> + unsigned char timing;
> bool vqmmc_enabled;
> + u32 hs400_ds_delay;
> struct msdc_save_para save_para; /* used when gate HCLK */
> };
>
> @@ -353,7 +381,10 @@ static void msdc_reset_hw(struct msdc_host *host)
> static void msdc_cmd_next(struct msdc_host *host,
> struct mmc_request *mrq, struct mmc_command *cmd);
>
> -static u32 data_ints_mask = MSDC_INTEN_XFER_COMPL | MSDC_INTEN_DATTMO |
> +static const u32 cmd_ints_mask = MSDC_INTEN_CMDRDY | MSDC_INTEN_RSPCRCERR |
> + MSDC_INTEN_CMDTMO | MSDC_INTEN_ACMDRDY |
> + MSDC_INTEN_ACMDCRCERR | MSDC_INTEN_ACMDTMO;

This belongs to separate code improvement patch.

> +static const u32 data_ints_mask = MSDC_INTEN_XFER_COMPL | MSDC_INTEN_DATTMO |
> MSDC_INTEN_DATCRCERR | MSDC_INTEN_DMA_BDCSERR |
> MSDC_INTEN_DMA_GPDCSERR | MSDC_INTEN_DMA_PROTECT;
>
> @@ -485,7 +516,7 @@ static void msdc_ungate_clock(struct msdc_host *host)
> cpu_relax();
> }
>
> -static void msdc_set_mclk(struct msdc_host *host, int ddr, u32 hz)
> +static void msdc_set_mclk(struct msdc_host *host, unsigned char timing, u32 hz)

Perhaps this change could be split into two changes.

One that breaks out code from ->set_ios() and let msdc_set_mclk() also
deals with DDR timings.

Second you add the HS400 specific parts.

> {
> u32 mode;
> u32 flags;
> @@ -501,8 +532,15 @@ static void msdc_set_mclk(struct msdc_host *host, int ddr, u32 hz)
>
> flags = readl(host->base + MSDC_INTEN);
> sdr_clr_bits(host->base + MSDC_INTEN, flags);
> - if (ddr) { /* may need to modify later */
> - mode = 0x2; /* ddr mode and use divisor */
> + sdr_clr_bits(host->base + MSDC_CFG, MSDC_CFG_HS400_CK_MODE);
> + if (timing == MMC_TIMING_UHS_DDR50 ||
> + timing == MMC_TIMING_MMC_DDR52 ||

So, no support for HS200?

> + timing == MMC_TIMING_MMC_HS400) {
> + if (timing == MMC_TIMING_MMC_HS400)
> + mode = 0x3;
> + else
> + mode = 0x2; /* ddr mode and use divisor */
> +
> if (hz >= (host->src_clk_freq >> 2)) {
> div = 0; /* mean div = 1/4 */
> sclk = host->src_clk_freq >> 2; /* sclk = clk / 4 */
> @@ -511,6 +549,13 @@ static void msdc_set_mclk(struct msdc_host *host, int ddr, u32 hz)
> sclk = (host->src_clk_freq >> 2) / div;
> div = (div >> 1);
> }
> +
> + if (timing == MMC_TIMING_MMC_HS400 &&
> + hz >= (host->src_clk_freq >> 1)) {
> + sdr_set_bits(host->base + MSDC_CFG, MSDC_CFG_HS400_CK_MODE);
> + sclk = host->src_clk_freq >> 1;
> + div = 0; /* div is ignore when bit18 is set */
> + }
> } else if (hz >= host->src_clk_freq) {
> mode = 0x1; /* no divisor */
> div = 0;
> @@ -532,12 +577,12 @@ static void msdc_set_mclk(struct msdc_host *host, int ddr, u32 hz)
> cpu_relax();
> host->sclk = sclk;
> host->mclk = hz;
> - host->ddr = ddr;
> + host->timing = timing;
> /* need because clk changed. */
> msdc_set_timeout(host, host->timeout_ns, host->timeout_clks);
> sdr_set_bits(host->base + MSDC_INTEN, flags);
>
> - dev_dbg(host->dev, "sclk: %d, ddr: %d\n", host->sclk, ddr);
> + dev_dbg(host->dev, "sclk: %d, timing: %d\n", host->sclk, timing);
> }
>
> static inline u32 msdc_cmd_find_resp(struct msdc_host *host,
> @@ -725,10 +770,7 @@ static bool msdc_cmd_done(struct msdc_host *host, int events,
> if (done)
> return true;
>
> - sdr_clr_bits(host->base + MSDC_INTEN, MSDC_INTEN_CMDRDY |
> - MSDC_INTEN_RSPCRCERR | MSDC_INTEN_CMDTMO |
> - MSDC_INTEN_ACMDRDY | MSDC_INTEN_ACMDCRCERR |
> - MSDC_INTEN_ACMDTMO);
> + sdr_clr_bits(host->base + MSDC_INTEN, cmd_ints_mask);

This belongs to separate code improvement patch.

>
> if (cmd->flags & MMC_RSP_PRESENT) {
> if (cmd->flags & MMC_RSP_136) {
> @@ -818,10 +860,7 @@ static void msdc_start_command(struct msdc_host *host,
> rawcmd = msdc_cmd_prepare_raw_cmd(host, mrq, cmd);
> mod_delayed_work(system_wq, &host->req_timeout, DAT_TIMEOUT);
>
> - sdr_set_bits(host->base + MSDC_INTEN, MSDC_INTEN_CMDRDY |
> - MSDC_INTEN_RSPCRCERR | MSDC_INTEN_CMDTMO |
> - MSDC_INTEN_ACMDRDY | MSDC_INTEN_ACMDCRCERR |
> - MSDC_INTEN_ACMDTMO);
> + sdr_set_bits(host->base + MSDC_INTEN, cmd_ints_mask);

This belongs to separate code improvement patch.

> writel(cmd->arg, host->base + SDC_ARG);
> writel(rawcmd, host->base + SDC_CMD);
> }
> @@ -895,7 +934,7 @@ static void msdc_data_xfer_next(struct msdc_host *host,
> struct mmc_request *mrq, struct mmc_data *data)
> {
> if (mmc_op_multi(mrq->cmd->opcode) && mrq->stop && !mrq->stop->error &&
> - (!data->bytes_xfered || !mrq->sbc))
> + !mrq->sbc)
> msdc_start_command(host, mrq, mrq->stop);
> else
> msdc_request_done(host, mrq);
> @@ -929,7 +968,7 @@ static bool msdc_data_xfer_done(struct msdc_host *host, u32 events,
> while (readl(host->base + MSDC_DMA_CFG) & MSDC_DMA_CFG_STS)
> cpu_relax();
> sdr_clr_bits(host->base + MSDC_INTEN, data_ints_mask);
> - dev_dbg(host->dev, "DMA stop\n");
> + dev_dbg(host->dev, "DMA stop event:0x%x\n", events);

Perhaps a separate debug patch?

>
> if ((events & MSDC_INT_XFER_COMPL) && (!stop || !stop->error)) {
> data->bytes_xfered = data->blocks * data->blksz;
> @@ -941,6 +980,8 @@ static bool msdc_data_xfer_done(struct msdc_host *host, u32 events,
>
> if (events & MSDC_INT_DATTMO)
> data->error = -ETIMEDOUT;
> + else if (events & MSDC_INT_DATCRCERR)
> + data->error = -EILSEQ;
>
> dev_err(host->dev, "%s: cmd=%d; blocks=%d",
> __func__, mrq->cmd->opcode, data->blocks);
> @@ -1112,10 +1153,14 @@ static void msdc_init_hw(struct msdc_host *host)
>
> writel(0, host->base + MSDC_PAD_TUNE);
> writel(0, host->base + MSDC_IOCON);
> - sdr_set_field(host->base + MSDC_IOCON, MSDC_IOCON_DDLSEL, 1);
> - writel(0x403c004f, host->base + MSDC_PATCH_BIT);
> + sdr_set_field(host->base + MSDC_IOCON, MSDC_IOCON_DDLSEL, 0);
> + writel(0x403c0046, host->base + MSDC_PATCH_BIT);
> sdr_set_field(host->base + MSDC_PATCH_BIT, MSDC_CKGEN_MSDC_DLY_SEL, 1);
> writel(0xffff0089, host->base + MSDC_PATCH_BIT1);
> + sdr_set_bits(host->base + EMMC50_CFG0, EMMC50_CFG_CFCSTS_SEL);
> +
> + if (host->mmc->caps2 & MMC_CAP2_HS400_1_8V)

Should you really do this even if the HS400 mode isn't supported by
the card, and thus we will never switch timing to that mode?

So, I am kind of wondering if this shouldn't be conditional depending
on the current selected timing mode. Or perhaps you need this done
from a ->prepare_hs400_tuning() callback)?

> + writel(host->hs400_ds_delay, host->base + PAD_DS_TUNE);
> /* Configure to enable SDIO mode.
> * it's must otherwise sdio cmd5 failed
> */
> @@ -1151,7 +1196,6 @@ static void msdc_init_gpd_bd(struct msdc_host *host, struct msdc_dma *dma)
>
> gpd->gpd_info = GPDMA_DESC_BDP; /* hwo, cs, bd pointer */
> gpd->ptr = (u32)dma->bd_addr; /* physical address */
> -

White space.

> memset(bd, 0, sizeof(struct mt_bdma_desc) * MAX_BD_NUM);
> for (i = 0; i < (MAX_BD_NUM - 1); i++)
> bd[i].next = (u32)dma->bd_addr + sizeof(*bd) * (i + 1);
> @@ -1161,20 +1205,16 @@ static void msdc_ops_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> {
> struct msdc_host *host = mmc_priv(mmc);
> int ret;
> - u32 ddr = 0;
>
> pm_runtime_get_sync(host->dev);
>
> - if (ios->timing == MMC_TIMING_UHS_DDR50 ||
> - ios->timing == MMC_TIMING_MMC_DDR52)
> - ddr = 1;
> -
> msdc_set_buswidth(host, ios->bus_width);
>
> /* Suspend/Resume will do power off/on */
> switch (ios->power_mode) {
> case MMC_POWER_UP:
> if (!IS_ERR(mmc->supply.vmmc)) {
> + msdc_init_hw(host);
> ret = mmc_regulator_set_ocr(mmc, mmc->supply.vmmc,
> ios->vdd);
> if (ret) {
> @@ -1205,14 +1245,259 @@ static void msdc_ops_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> break;
> }
>
> - if (host->mclk != ios->clock || host->ddr != ddr)
> - msdc_set_mclk(host, ddr, ios->clock);
> + if (host->mclk != ios->clock || host->timing != ios->timing)
> + msdc_set_mclk(host, ios->timing, ios->clock);
>
> end:
> pm_runtime_mark_last_busy(host->dev);
> pm_runtime_put_autosuspend(host->dev);
> }
>
> +static u32 test_delay_bit(u32 delay, u32 bit)
> +{
> + bit %= DELAY_MAX;
> + return delay & (1 << bit);
> +}
> +
> +static int get_delay_len(u32 delay, u32 start_bit)
> +{
> + int i;
> +
> + for (i = 0; i < (DELAY_MAX - start_bit); i++) {
> + if (test_delay_bit(delay, start_bit + i) == 0)
> + return i;
> + }
> + return DELAY_MAX - start_bit;
> +}
> +
> +static struct msdc_delay_phase get_best_delay(u32 delay)
> +{
> + int start = 0, len = 0;
> + int start_final = 0, len_final = 0;
> + u8 final_phase = 0xff;
> + struct msdc_delay_phase delay_phase;
> +
> + if (delay == 0) {
> + pr_err("phase error: [map:%x]\n", delay);

Please use dev_err|warn|dbg|info instead.

> + delay_phase.final_phase = final_phase;
> + return delay_phase;
> + }
> +
> + while (start < DELAY_MAX) {
> + len = get_delay_len(delay, start);
> + if (len_final < len) {
> + start_final = start;
> + len_final = len;
> + }
> + start += len ? len : 1;
> + if (len >= 8 && start_final < 4)
> + break;
> + }
> +
> + /* The rule is that to find the smallest delay cell */
> + if (start_final == 0)
> + final_phase = (start_final + len_final / 3) % DELAY_MAX;
> + else
> + final_phase = (start_final + len_final / 2) % DELAY_MAX;
> + pr_info("phase: [map:%x] [maxlen:%d] [final:%d]\n",
> + delay, len_final, final_phase);

Same comment as above.

> +
> + delay_phase.maxlen = len_final;
> + delay_phase.start = start_final;
> + delay_phase.final_phase = final_phase;
> + return delay_phase;
> +}
> +
> +static int msdc_send_tuning(struct mmc_host *host, u32 opcode, int *cmd_error)

I think you can remove this function and use mmc_send_tuning() instead.

> +{
> + struct mmc_request mrq = {NULL};
> + struct mmc_command cmd = {0};
> + struct mmc_data data = {0};
> + struct scatterlist sg;
> + struct mmc_ios *ios = &host->ios;
> + int size, err = 0;
> + u8 *data_buf;
> +
> + if (ios->bus_width == MMC_BUS_WIDTH_8)
> + size = 128;
> + else if (ios->bus_width == MMC_BUS_WIDTH_4)
> + size = 64;
> + else
> + return -EINVAL;
> +
> + data_buf = kzalloc(size, GFP_KERNEL);
> + if (!data_buf)
> + return -ENOMEM;
> +
> + mrq.cmd = &cmd;
> + mrq.data = &data;
> +
> + cmd.opcode = opcode;
> + cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
> +
> + data.blksz = size;
> + data.blocks = 1;
> + data.flags = MMC_DATA_READ;
> +
> + /*
> + * According to the tuning specs, Tuning process
> + * is normally shorter 40 executions of CMD19,
> + * and timeout value should be shorter than 150 ms
> + */
> + data.timeout_ns = 150 * NSEC_PER_MSEC;
> +
> + data.sg = &sg;
> + data.sg_len = 1;
> + sg_init_one(&sg, data_buf, size);
> +
> + mmc_wait_for_req(host, &mrq);
> +
> + if (cmd_error)
> + *cmd_error = cmd.error;
> +
> + if (cmd.error) {
> + err = cmd.error;
> + goto out;
> + }
> +
> + if (data.error) {
> + err = data.error;
> + goto out;
> + }
> +
> +out:
> + kfree(data_buf);
> + return err;
> +}
> +
> +static int msdc_tune_response(struct mmc_host *mmc, u32 opcode)
> +{
> + struct msdc_host *host = mmc_priv(mmc);
> + u32 rise_delay = 0, fall_delay = 0;
> + struct msdc_delay_phase final_rise_delay, final_fall_delay;
> + u8 final_delay, final_maxlen;
> + int cmd_err;
> + int i;
> +
> + sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_RSPL);
> + for (i = 0 ; i < DELAY_MAX; i++) {
> + sdr_set_field(host->base + MSDC_PAD_TUNE, MSDC_PAD_TUNE_CMDRDLY, i);
> + msdc_send_tuning(mmc, opcode, &cmd_err);
> + if (!cmd_err)
> + rise_delay |= (1 << i);
> + }
> +
> + sdr_set_bits(host->base + MSDC_IOCON, MSDC_IOCON_RSPL);
> + for (i = 0; i < DELAY_MAX; i++) {
> + sdr_set_field(host->base + MSDC_PAD_TUNE, MSDC_PAD_TUNE_CMDRDLY, i);
> + msdc_send_tuning(mmc, opcode, &cmd_err);
> + if (!cmd_err)
> + fall_delay |= (1 << i);
> + }
> +
> + final_rise_delay = get_best_delay(rise_delay);
> + final_fall_delay = get_best_delay(fall_delay);
> +
> + final_maxlen = max(final_rise_delay.maxlen, final_fall_delay.maxlen);
> + if (final_maxlen == final_rise_delay.maxlen) {
> + sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_RSPL);
> + sdr_set_field(host->base + MSDC_PAD_TUNE, MSDC_PAD_TUNE_CMDRDLY,
> + final_rise_delay.final_phase);
> + final_delay = final_rise_delay.final_phase;
> + } else {
> + sdr_set_bits(host->base + MSDC_IOCON, MSDC_IOCON_RSPL);
> + sdr_set_field(host->base + MSDC_PAD_TUNE, MSDC_PAD_TUNE_CMDRDLY,
> + final_fall_delay.final_phase);
> + final_delay = final_fall_delay.final_phase;
> + }
> +
> + return final_delay;
> +}
> +
> +static int msdc_tune_data(struct mmc_host *mmc, u32 opcode)
> +{
> + struct msdc_host *host = mmc_priv(mmc);
> + u32 rise_delay = 0, fall_delay = 0;
> + struct msdc_delay_phase final_rise_delay, final_fall_delay;
> + u8 final_delay, final_maxlen;
> + int i, ret;
> +
> + sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_DSPL);
> + sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_W_DSPL);
> + for (i = 0 ; i < DELAY_MAX; i++) {
> + sdr_set_field(host->base + MSDC_PAD_TUNE, MSDC_PAD_TUNE_DATRRDLY, i);
> + ret = msdc_send_tuning(mmc, opcode, NULL);
> + if (!ret)
> + rise_delay |= (1 << i);
> + }
> +
> + sdr_set_bits(host->base + MSDC_IOCON, MSDC_IOCON_DSPL);
> + sdr_set_bits(host->base + MSDC_IOCON, MSDC_IOCON_W_DSPL);
> + for (i = 0; i < DELAY_MAX; i++) {
> + sdr_set_field(host->base + MSDC_PAD_TUNE, MSDC_PAD_TUNE_DATRRDLY, i);
> + ret = msdc_send_tuning(mmc, opcode, NULL);
> + if (!ret)
> + fall_delay |= (1 << i);
> + }
> +
> + final_rise_delay = get_best_delay(rise_delay);
> + final_fall_delay = get_best_delay(fall_delay);
> +
> + final_maxlen = max(final_rise_delay.maxlen, final_fall_delay.maxlen);
> + /* Rising edge is more stable, prefer to use it */
> + if (final_rise_delay.maxlen >= 10)
> + final_maxlen = final_rise_delay.maxlen;
> + if (final_maxlen == final_rise_delay.maxlen) {
> + sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_DSPL);
> + sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_W_DSPL);
> + sdr_set_field(host->base + MSDC_PAD_TUNE, MSDC_PAD_TUNE_DATRRDLY,
> + final_rise_delay.final_phase);
> + final_delay = final_rise_delay.final_phase;
> + } else {
> + sdr_set_bits(host->base + MSDC_IOCON, MSDC_IOCON_DSPL);
> + sdr_set_bits(host->base + MSDC_IOCON, MSDC_IOCON_W_DSPL);
> + sdr_set_field(host->base + MSDC_PAD_TUNE, MSDC_PAD_TUNE_DATRRDLY,
> + final_fall_delay.final_phase);
> + final_delay = final_fall_delay.final_phase;
> + }
> +
> + return final_delay;
> +}
> +
> +static int msdc_execute_tuning(struct mmc_host *mmc, u32 opcode)
> +{
> + struct msdc_host *host = mmc_priv(mmc);
> + int ret;
> +
> + pm_runtime_get_sync(host->dev);
> + ret = msdc_tune_response(mmc, opcode);

I suggest that msdc_tune_response() return a proper error code
instead, this seems a bit odd.

> + if (ret == 0xff) {
> + dev_err(host->dev, "Tune response fail!\n");
> + ret = -EIO;
> + goto out;
> + }
> + ret = msdc_tune_data(mmc, opcode);

Same comment as above.

> + if (ret == 0xff) {
> + dev_err(host->dev, "Tune data fail!\n");
> + ret = -EIO;
> + goto out;
> + }
> + ret = 0;

Following my suggestions will make the above assignment redunant, so
you should be able to remove it.

> +out:
> + pm_runtime_mark_last_busy(host->dev);
> + pm_runtime_put_autosuspend(host->dev);
> + return ret;
> +}
> +
> +static void msdc_hw_reset(struct mmc_host *mmc)

I assume this will reset the card?

I also thinks this belongs in a separate patch.

> +{
> + struct msdc_host *host = mmc_priv(mmc);
> +
> + sdr_set_bits(host->base + EMMC_IOCON, 1);
> + udelay(10); /* 10us is enough */
> + sdr_clr_bits(host->base + EMMC_IOCON, 1);
> +}
> +
> static struct mmc_host_ops mt_msdc_ops = {
> .post_req = msdc_post_req,
> .pre_req = msdc_pre_req,
> @@ -1220,6 +1505,8 @@ static struct mmc_host_ops mt_msdc_ops = {
> .set_ios = msdc_ops_set_ios,
> .start_signal_voltage_switch = msdc_ops_switch_volt,
> .card_busy = msdc_card_busy,
> + .execute_tuning = msdc_execute_tuning,
> + .hw_reset = msdc_hw_reset,

Same comment as above.

> };
>
> static int msdc_drv_probe(struct platform_device *pdev)
> @@ -1260,6 +1547,16 @@ static int msdc_drv_probe(struct platform_device *pdev)
> goto host_free;
> }
>
> + host->src_clk_parent = clk_get_parent(host->src_clk);

Don't you need to check the return value here?

> + host->hs400_src = devm_clk_get(&pdev->dev, "400mhz");

That's a really weird conid for a clock. If it's not too late to
change, please do that!

> + if (IS_ERR(host->hs400_src)) {
> + dev_dbg(&pdev->dev, "Cannot find 400mhz at dts!\n");
> + } else if (clk_set_parent(host->src_clk_parent, host->hs400_src) < 0) {
> + dev_err(host->dev, "Failed to set 400mhz source clock!\n");
> + ret = -EINVAL;

I think it seems more apropriate to use the return value from
clk_set_parent() instead of inventing your own return value.

> + goto host_free;
> + }

It seems like you don't need to store the src_clk_parent and the
hs400_src in the host struct, as you are only using it during
->probe().

> +
> host->h_clk = devm_clk_get(&pdev->dev, "hclk");
> if (IS_ERR(host->h_clk)) {
> ret = PTR_ERR(host->h_clk);
> @@ -1293,6 +1590,10 @@ static int msdc_drv_probe(struct platform_device *pdev)
> goto host_free;
> }
>
> + if (!of_property_read_u32(pdev->dev.of_node, "hs400-ds-delay",
> + &host->hs400_ds_delay))
> + dev_dbg(&pdev->dev, "hs400-ds-delay: %x\n", host->hs400_ds_delay);
> +
> host->dev = &pdev->dev;
> host->mmc = mmc;
> host->src_clk_freq = clk_get_rate(host->src_clk);
> @@ -1403,6 +1704,8 @@ static void msdc_save_reg(struct msdc_host *host)
> host->save_para.pad_tune = readl(host->base + MSDC_PAD_TUNE);
> host->save_para.patch_bit0 = readl(host->base + MSDC_PATCH_BIT);
> host->save_para.patch_bit1 = readl(host->base + MSDC_PATCH_BIT1);
> + host->save_para.pad_ds_tune = readl(host->base + PAD_DS_TUNE);
> + host->save_para.emmc50_cfg0 = readl(host->base + EMMC50_CFG0);
> }
>
> static void msdc_restore_reg(struct msdc_host *host)
> @@ -1413,6 +1716,8 @@ static void msdc_restore_reg(struct msdc_host *host)
> writel(host->save_para.pad_tune, host->base + MSDC_PAD_TUNE);
> writel(host->save_para.patch_bit0, host->base + MSDC_PATCH_BIT);
> writel(host->save_para.patch_bit1, host->base + MSDC_PATCH_BIT1);
> + writel(host->save_para.pad_ds_tune, host->base + PAD_DS_TUNE);
> + writel(host->save_para.emmc50_cfg0, host->base + EMMC50_CFG0);
> }
>
> static int msdc_runtime_suspend(struct device *dev)
> --
> 1.8.1.1.dirty
>

Kind regards
Uffe
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