Re: [PATCH 3/3] mmc: mediatek: add optional module reset property
From: Philipp Zabel <p.zabel@pengutronix.de>
Date: 2020-08-12 12:08:28
Also in:
linux-arm-kernel, linux-mediatek, linux-mmc, lkml
On Wed, 2020-08-12 at 17:37 +0800, Wenbin Mei wrote:
quoted hunk ↗ jump to hunk
This patch adds a optional reset management for msdc. Sometimes the bootloader does not bring msdc register to default state, so need reset the msdc controller. Signed-off-by: Wenbin Mei <redacted> --- drivers/mmc/host/mtk-sd.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c index 39e7fc54c438..2b243c03c9b2 100644 --- a/drivers/mmc/host/mtk-sd.c +++ b/drivers/mmc/host/mtk-sd.c@@ -22,6 +22,7 @@ #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/interrupt.h> +#include <linux/reset.h> #include <linux/mmc/card.h> #include <linux/mmc/core.h>@@ -434,6 +435,7 @@ struct msdc_host { struct msdc_save_para save_para; /* used when gate HCLK */ struct msdc_tune_para def_tune_para; /* default tune setting */ struct msdc_tune_para saved_tune_para; /* tune result of CMD21/CMD19 */ + struct reset_control *reset; }; static const struct mtk_mmc_compatible mt8135_compat = {@@ -1516,6 +1518,12 @@ static void msdc_init_hw(struct msdc_host *host) u32 val; u32 tune_reg = host->dev_comp->pad_tune_reg; + if (!IS_ERR(host->reset)) { + reset_control_assert(host->reset); + usleep_range(10, 50); + reset_control_deassert(host->reset); + } +
This should be:
if (host->reset) {
reset_control_assert(host->reset);
usleep_range(10, 50);
reset_control_deassert(host->reset);
}
quoted hunk ↗ jump to hunk
/* Configure to MMC/SD mode, clock free running */ sdr_set_bits(host->base + MSDC_CFG, MSDC_CFG_MODE | MSDC_CFG_CKPDN);@@ -2273,6 +2281,11 @@ static int msdc_drv_probe(struct platform_device *pdev) if (IS_ERR(host->src_clk_cg)) host->src_clk_cg = NULL; + host->reset = devm_reset_control_get_optional_exclusive(&pdev->dev, + "hrst"); + if (PTR_ERR(host->reset) == -EPROBE_DEFER) + return PTR_ERR(host->reset); +
This should be: host->reset = devm_reset_control_get_optional_exclusive(&pdev->dev, "hrst"); if (IS_ERR(host->reset)) return PTR_ERR(host->reset); If the reset is configured in DT then it should be used, even if the reset driver is loaded later. If the DT does not contain the reset-names = "hrst" property at all, devm_reset_control_get_optional_*() will return NULL. With these two changes, Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de> regards Philipp