Hi Guodong, On 08/11/2016 11:23 AM, Shawn Lin wrote: > On 2016/8/10 16:03, Guodong Xu wrote: >> Dwmmc host controller may in unknown state when entering kernel boot. One >> example is when booting from eMMC, bootloader need initialize MMC host >> controller into some state so it can read. In order to make sure MMC host >> controller in a clean initial state, this reset support is added. >> >> With this patch, a 'resets' property can be added into dw_mmc device >> tree node. The hardware logic is: dwmmc host controller IP receives a reset >> signal from a 'reset provider' (eg. power management unit). The 'resets' >> property points to this reset signal. So, during dwmmc driver probe, >> it can use this signal to reset itself. >> >> Refer to [1] for more information. >> >> [1] Documentation/devicetree/bindings/reset/reset.txt >> >> Signed-off-by: Guodong Xu <guodong.xu@xxxxxxxxxx> >> Signed-off-by: Xinwei Kong <kong.kongxinwei@xxxxxxxxxxxxx> >> Signed-off-by: Zhangfei Gao <zhangfei.gao@xxxxxxxxxx> > > Looks good to me, > > Reviewed-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> Could you rebase on https://github.com/jh80chung/dw-mmc.git? Otherwise, when i apply your patch, i will rebase. Best Regards, Jaehoon Chung > >> --- >> drivers/mmc/host/dw_mmc.c | 23 ++++++++++++++++++++++- >> include/linux/mmc/dw_mmc.h | 2 ++ >> 2 files changed, 24 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c >> index 32380d5..481d441 100644 >> --- a/drivers/mmc/host/dw_mmc.c >> +++ b/drivers/mmc/host/dw_mmc.c >> @@ -2915,6 +2915,13 @@ static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host) >> if (!pdata) >> return ERR_PTR(-ENOMEM); >> >> + /* find reset controller when exist */ >> + pdata->rstc = devm_reset_control_get_optional(dev, NULL); >> + if (IS_ERR(pdata->rstc)) { >> + if (PTR_ERR(pdata->rstc) == -EPROBE_DEFER) >> + return ERR_PTR(-EPROBE_DEFER); >> + } >> + >> /* find out number of slots supported */ >> of_property_read_u32(np, "num-slots", &pdata->num_slots); >> >> @@ -2986,7 +2993,9 @@ int dw_mci_probe(struct dw_mci *host) >> >> if (!host->pdata) { >> host->pdata = dw_mci_parse_dt(host); >> - if (IS_ERR(host->pdata)) { >> + if (PTR_ERR(host->pdata) == -EPROBE_DEFER) { >> + return -EPROBE_DEFER; >> + } else if (IS_ERR(host->pdata)) { >> dev_err(host->dev, "platform data not available\n"); >> return -EINVAL; >> } >> @@ -3040,6 +3049,12 @@ int dw_mci_probe(struct dw_mci *host) >> } >> } >> >> + if (!IS_ERR(host->pdata->rstc)) { >> + reset_control_assert(host->pdata->rstc); >> + usleep_range(10, 50); >> + reset_control_deassert(host->pdata->rstc); >> + } >> + >> setup_timer(&host->cmd11_timer, >> dw_mci_cmd11_timer, (unsigned long)host); >> >> @@ -3189,6 +3204,9 @@ err_dmaunmap: >> if (host->use_dma && host->dma_ops->exit) >> host->dma_ops->exit(host); >> >> + if (!IS_ERR(host->pdata->rstc)) >> + reset_control_assert(host->pdata->rstc); >> + >> err_clk_ciu: >> if (!IS_ERR(host->ciu_clk)) >> clk_disable_unprepare(host->ciu_clk); >> @@ -3221,6 +3239,9 @@ void dw_mci_remove(struct dw_mci *host) >> if (host->use_dma && host->dma_ops->exit) >> host->dma_ops->exit(host); >> >> + if (!IS_ERR(host->pdata->rstc)) >> + reset_control_assert(host->pdata->rstc); >> + >> if (!IS_ERR(host->ciu_clk)) >> clk_disable_unprepare(host->ciu_clk); >> >> diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h >> index 83b0edfc..f5af2bd 100644 >> --- a/include/linux/mmc/dw_mmc.h >> +++ b/include/linux/mmc/dw_mmc.h >> @@ -17,6 +17,7 @@ >> #include <linux/scatterlist.h> >> #include <linux/mmc/core.h> >> #include <linux/dmaengine.h> >> +#include <linux/reset.h> >> >> #define MAX_MCI_SLOTS 2 >> >> @@ -259,6 +260,7 @@ struct dw_mci_board { >> /* delay in mS before detecting cards after interrupt */ >> u32 detect_delay_ms; >> >> + struct reset_control *rstc; >> struct dw_mci_dma_ops *dma_ops; >> struct dma_pdata *data; >> }; >> > > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
