Re: [PATCH 1/4] mmc: mediatek: Add online-tuning support of EMMC/SD

Ulf Hansson
2015-08-17T11:31:58Z

On 12 August 2015 at 10:24, Chaotian Jing <chaotian.jing@mediatek.com> wrote:
> Schedule a workqueue to do tuning when CRC error
> Call mmc_hw_reset to re-init card when data timeout

Thanks to Adrian Hunter, the mmc core already supports re-tuning for
the above scenarios through the mmc_retune_*() APIs.

SDHCI driver has already adopted to use that feature, you should do
that for the mtk-sd driver as well.

Kind regards
Uffe

>
> Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com>
> ---
> drivers/mmc/host/mtk-sd.c | 162 ++++++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 150 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
> index 7153500..eb44fe1 100644
> --- a/drivers/mmc/host/mtk-sd.c
> +++ b/drivers/mmc/host/mtk-sd.c
> @@ -27,6 +27,7 @@
> #include <linux/pm_runtime.h>
> #include <linux/regulator/consumer.h>
> #include <linux/spinlock.h>
> +#include <linux/workqueue.h>
>
> #include <linux/mmc/card.h>
> #include <linux/mmc/core.h>
> @@ -290,6 +291,10 @@ struct msdc_host {
> struct pinctrl_state *pins_default;
> struct pinctrl_state *pins_uhs;
> struct delayed_work req_timeout;
> + struct workqueue_struct *repeat_workqueue;
> + struct work_struct repeat_req;
> + struct mmc_request *repeat_mrq;
> + u32 tune_cmd_counter;
> int irq; /* host interrupt */
>
> struct clk *src_clk; /* msdc source clock */
> @@ -353,7 +358,10 @@ 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;
> +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;
>
> @@ -690,6 +698,18 @@ static void msdc_request_done(struct msdc_host *host, struct mmc_request *mrq)
> msdc_track_cmd_data(host, mrq->cmd, mrq->data);
> if (mrq->data)
> msdc_unprepare_data(host, mrq);
> + if (host->error && host->mmc->card &&
> + !mmc_card_sdio(host->mmc->card)) {
> + if (mrq->cmd->error == (unsigned int)-EILSEQ ||
> + (mrq->stop && mrq->stop->error == (unsigned int)-EILSEQ) ||
> + (mrq->sbc && mrq->sbc->error == (unsigned int)-EILSEQ) ||
> + (mrq->data && mrq->data->error)) {
> + host->repeat_mrq = mrq;
> + queue_work(host->repeat_workqueue, &host->repeat_req);
> + return;
> + }
> + }
> + host->tune_cmd_counter = 0;
> mmc_request_done(host->mmc, mrq);
>
> pm_runtime_mark_last_busy(host->dev);
> @@ -725,11 +745,7 @@ 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);
> - writel(cmd->arg, host->base + SDC_ARG);
> + sdr_clr_bits(host->base + MSDC_INTEN, cmd_ints_mask);
>
> if (cmd->flags & MMC_RSP_PRESENT) {
> if (cmd->flags & MMC_RSP_136) {
> @@ -819,10 +835,7 @@ 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);
> writel(cmd->arg, host->base + SDC_ARG);
> writel(rawcmd, host->base + SDC_CMD);
> }
> @@ -942,6 +955,8 @@ 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);
> @@ -1113,8 +1128,8 @@ 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);
> /* Configure to enable SDIO mode.
> @@ -1176,6 +1191,7 @@ static void msdc_ops_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> 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) {
> @@ -1214,6 +1230,120 @@ end:
> pm_runtime_put_autosuspend(host->dev);
> }
>
> +static void msdc_reset_mrq(struct mmc_request *mrq)
> +{
> + mrq->cmd->error = 0;
> + if (mrq->sbc)
> + mrq->sbc->error = 0;
> + if (mrq->data)
> + mrq->data->error = 0;
> + if (mrq->stop)
> + mrq->stop->error = 0;
> +}
> +
> +/* Send CMD12 when tuning, do not check CRC error and timeout */
> +static void msdc_send_stop(struct msdc_host *host)
> +{
> + u32 opcode = MMC_STOP_TRANSMISSION;
> + u32 arg = 0;
> + u32 rawcmd = 0;
> + u32 intsts = 0;
> +
> + /* Reset host first */
> + msdc_reset_hw(host);
> +
> + rawcmd = (opcode & 0x3f) | (7 << 7);
> + rawcmd |= (1 << 14); /* stop cmd */
> +
> + sdr_clr_bits(host->base + MSDC_INTEN, cmd_ints_mask);
> + writel(arg, host->base + SDC_ARG);
> + writel(rawcmd, host->base + SDC_CMD);
> +
> + while (1) {
> + intsts = readl(host->base + MSDC_INT);
> + if (intsts) {
> + writel(intsts, host->base + MSDC_INT);
> + if (intsts & cmd_ints_mask) {
> + dev_dbg(host->dev, "result of cmd12: %x\n",
> + intsts);
> + break;
> + }
> + }
> + udelay(1);
> + }
> +}
> +
> +/* When tuning, CMD13 may also get crc error, so use MSDC_PS to get card status */
> +static void msdc_wait_card_not_busy(struct msdc_host *host)
> +{
> + while (1) {
> + if ((readl(host->base + MSDC_PS) & BIT(16)) == 0) { /* check dat0 status */
> + msleep_interruptible(10);
> + dev_dbg(host->dev, "MSDC_PS: %08x, SDC_STS: %08x\n",
> + readl(host->base + MSDC_PS), readl(host->base + SDC_STS));
> + } else
> + break;
> + }
> +}
> +
> +static void msdc_tune_request(struct msdc_host *host)
> +{
> + u32 orig_rsmpl, orig_cksel;
> + u32 cur_rsmpl, cur_cksel = 0;
> + u32 ddr, clkmode;
> + struct mmc_ios ios = host->mmc->ios;
> +
> + sdr_get_field(host->base + MSDC_IOCON, MSDC_IOCON_RSPL, &orig_rsmpl);
> + sdr_get_field(host->base + MSDC_PATCH_BIT, MSDC_CKGEN_MSDC_DLY_SEL,
> + &orig_cksel);
> + cur_rsmpl = (orig_rsmpl + 1);
> + sdr_set_field(host->base + MSDC_IOCON, MSDC_IOCON_RSPL, cur_rsmpl % 2);
> +
> + if (ios.timing != MMC_TIMING_MMC_HS400) {
> + sdr_set_field(host->base + MSDC_IOCON, MSDC_IOCON_DSPL,
> + cur_rsmpl % 2);
> + sdr_set_field(host->base + MSDC_IOCON, MSDC_IOCON_W_DSPL,
> + cur_rsmpl % 2);
> + }
> +
> + if (cur_rsmpl >= 2) {
> + cur_cksel = orig_cksel + 1;
> + sdr_set_field(host->base + MSDC_PATCH_BIT,
> + MSDC_CKGEN_MSDC_DLY_SEL, cur_cksel % 16);
> + }
> +
> + if (host->tune_cmd_counter++ >= 2 * 16) {
> + dev_warn(host->dev, "Tune fail at %dhz\n", host->mclk);
> + host->tune_cmd_counter = 0;
> + sdr_set_field(host->base + MSDC_IOCON, MSDC_IOCON_RSPL, 0);
> + sdr_set_field(host->base + MSDC_PATCH_BIT,
> + MSDC_CKGEN_MSDC_DLY_SEL, 0);
> + sdr_get_field(host->base + MSDC_CFG, MSDC_CFG_CKMOD, &clkmode);
> + ddr = (clkmode == 2) ? 1 : 0;
> + msdc_set_mclk(host, ddr, host->mclk / 2);
> + }
> +}
> +
> +static void msdc_repeat_request(struct work_struct *work)
> +{
> + struct msdc_host *host = container_of(work, struct msdc_host, repeat_req);
> + struct mmc_request *mrq;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&host->lock, flags);
> + mrq = host->repeat_mrq;
> + host->repeat_mrq = NULL;
> + spin_unlock_irqrestore(&host->lock, flags);
> + msdc_send_stop(host);
> + msdc_wait_card_not_busy(host);
> + if (mrq->data && mrq->data->error == -ETIMEDOUT)
> + mmc_hw_reset(host->mmc);
> + else
> + msdc_tune_request(host);
> + msdc_reset_mrq(mrq);
> + msdc_ops_request(host->mmc, mrq);
> +}
> +
> static struct mmc_host_ops mt_msdc_ops = {
> .post_req = msdc_post_req,
> .pre_req = msdc_pre_req,
> @@ -1324,6 +1454,12 @@ static int msdc_drv_probe(struct platform_device *pdev)
> }
> msdc_init_gpd_bd(host, &host->dma);
> INIT_DELAYED_WORK(&host->req_timeout, msdc_request_timeout);
> + host->repeat_workqueue = create_singlethread_workqueue("repeat_workqueue");
> + if (!host->repeat_workqueue) {
> + ret = -ENOMEM;
> + goto release_mem;
> + }
> + INIT_WORK(&host->repeat_req, msdc_repeat_request);
> spin_lock_init(&host->lock);
>
> platform_set_drvdata(pdev, mmc);
> @@ -1348,6 +1484,7 @@ static int msdc_drv_probe(struct platform_device *pdev)
> end:
> pm_runtime_disable(host->dev);
> release:
> + destroy_workqueue(host->repeat_workqueue);
> platform_set_drvdata(pdev, NULL);
> msdc_deinit_hw(host);
> msdc_gate_clock(host);
> @@ -1383,6 +1520,7 @@ static int msdc_drv_remove(struct platform_device *pdev)
>
> pm_runtime_disable(host->dev);
> pm_runtime_put_noidle(host->dev);
> + destroy_workqueue(host->repeat_workqueue);
> dma_free_coherent(&pdev->dev,
> sizeof(struct mt_gpdma_desc),
> host->dma.gpd, host->dma.gpd_addr);
> --
> 1.8.1.1.dirty
>