[PATCH v2 14/16] mmc: meson-gx: implement voltage switch callback
From: jbrunet@baylibre.com (Jerome Brunet)
Date: 2017-08-21 16:04:00
Also in:
linux-amlogic, linux-mmc, lkml
Subsystem:
arm/amlogic meson soc support, multimedia card (mmc), secure digital (sd) and sdio subsystem, the rest · Maintainers:
Neil Armstrong, Kevin Hilman, Ulf Hansson, Linus Torvalds
Implement voltage switch callback (shamelessly copied from sunxi mmc driver). This allow, with the appropriate tuning function, to use SD ultra high speed modes. Reviewed-by: Kevin Hilman <khilman@baylibre.com> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> --- drivers/mmc/host/meson-gx-mmc.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+)
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index df1ac96bd0db..3167f561e1a6 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c@@ -1050,6 +1050,28 @@ static int meson_mmc_card_busy(struct mmc_host *mmc) return !(FIELD_GET(STATUS_DATI, regval) & 0xf); } +static int meson_mmc_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios) +{ + /* vqmmc regulator is available */ + if (!IS_ERR(mmc->supply.vqmmc)) { + /* + * The usual amlogic setup uses a GPIO to switch from one + * regulator to the other. While the voltage ramp up is + * pretty fast, care must be taken when switching from 3.3v + * to 1.8v. Please make sure the regulator framework is aware + * of your own regulator constraints + */ + return mmc_regulator_set_vqmmc(mmc, ios); + + } + + /* no vqmmc regulator, assume fixed regulator at 3/3.3V */ + if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330) + return 0; + + return -EINVAL; +} + static const struct mmc_host_ops meson_mmc_ops = { .request = meson_mmc_request, .set_ios = meson_mmc_set_ios,
@@ -1058,6 +1080,7 @@ static const struct mmc_host_ops meson_mmc_ops = { .post_req = meson_mmc_post_req, .execute_tuning = meson_mmc_execute_tuning, .card_busy = meson_mmc_card_busy, + .start_signal_voltage_switch = meson_mmc_voltage_switch, }; static int meson_mmc_probe(struct platform_device *pdev)
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2.9.5