This patch enables support for power-on sequencing of SDIO peripherals through DT. In general, it's quite common that wifi modules and other similar peripherals have several signals in addition to the SDIO interface that needs wiggling before the module will power on. For example: we need enable wifi module power to via the WL_REG_ON pin, we need enable it as the regulator if this pin is connected to the gpio of cpu. Maybe, someone will say that can pull up/down from dts. Unfortunately some SoCs can't support pinctrl pull up/down in internal. Anyway, we can add this patch to supprt the power-on sequencing for sdio. Signed-off-by: Caesar Wang <wxt@xxxxxxxxxxxxxx> --- Changes in v2: - This fix inmmc-power-sequences, as Heiko comment on https://patchwork.kernel.org/patch/7903161/ drivers/mmc/core/pwrseq_simple.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c index d10538b..455dd0c 100644 --- a/drivers/mmc/core/pwrseq_simple.c +++ b/drivers/mmc/core/pwrseq_simple.c @@ -14,6 +14,7 @@ #include <linux/err.h> #include <linux/of_gpio.h> #include <linux/gpio/consumer.h> +#include <linux/regulator/consumer.h> #include <linux/mmc/host.h> @@ -24,6 +25,7 @@ struct mmc_pwrseq_simple { bool clk_enabled; struct clk *ext_clk; struct gpio_descs *reset_gpios; + struct regulator *regulator; }; static void mmc_pwrseq_simple_set_gpios_value(struct mmc_pwrseq_simple *pwrseq, @@ -45,6 +47,13 @@ static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host) struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq, struct mmc_pwrseq_simple, pwrseq); + if (!IS_ERR(pwrseq->regulator)) { + dev_dbg(host->parent, "Enabling external regulator\n"); + if (regulator_enable(pwrseq->regulator)) + dev_err(host->parent, + "Failed to enable external regulator\n"); + } + if (!IS_ERR(pwrseq->ext_clk) && !pwrseq->clk_enabled) { clk_prepare_enable(pwrseq->ext_clk); pwrseq->clk_enabled = true; @@ -117,6 +126,13 @@ struct mmc_pwrseq *mmc_pwrseq_simple_alloc(struct mmc_host *host, goto clk_put; } + pwrseq->regulator = devm_regulator_get(dev, "ext-vcc"); + if (IS_ERR(pwrseq->regulator) && + PTR_ERR(pwrseq->regulator) != -EPROBE_DEFER) { + ret = PTR_ERR(pwrseq->regulator); + goto clk_put; + } + pwrseq->pwrseq.ops = &mmc_pwrseq_simple_ops; return &pwrseq->pwrseq; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
