On 11 August 2016 at 18:30, Jaehoon Chung <jh80.chung@xxxxxxxxxxx> wrote: > 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. > Sure, I rebased. Sending v5. -Guodong > 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
