Re: [PATCH 2/7] mmc: tegra: Reconfigure pad voltages during voltage switching
From: Mikko Perttunen
Date: Wed Jul 25 2018 - 02:41:23 EST
On 20.07.2018 15:45, Aapo Vienamo wrote:
Parse the pinctrl states from the device tree and implement pad voltage
state reconfiguration in the mmc start_signal_voltage_switch() callback.
This is done in the mmc callback because the order of pad
reconfiguration and sdhci voltage switch depend on the voltage to which
the transition occurs.
Add NVQUIRK_NEEDS_PAD_CONTROL and add set it for Tegra210 and Tegra186.
Signed-off-by: Aapo Vienamo <avienamo@xxxxxxxxxx>
---
drivers/mmc/host/sdhci-tegra.c | 91 +++++++++++++++++++++++++++++++++++++++---
1 file changed, 85 insertions(+), 6 deletions(-)
diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index ddf00166..f108c48 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -21,6 +21,7 @@
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_device.h>
+#include <linux/pinctrl/consumer.h>
#include <linux/reset.h>
#include <linux/mmc/card.h>
#include <linux/mmc/host.h>
@@ -55,6 +56,7 @@
#define NVQUIRK_ENABLE_SDR104 BIT(4)
#define NVQUIRK_ENABLE_DDR50 BIT(5)
#define NVQUIRK_HAS_PADCALIB BIT(6)
+#define NVQUIRK_NEEDS_PAD_CONTROL BIT(7)
struct sdhci_tegra_soc_data {
const struct sdhci_pltfm_data *pdata;
@@ -66,8 +68,12 @@ struct sdhci_tegra {
struct gpio_desc *power_gpio;
bool ddr_signaling;
bool pad_calib_required;
+ bool pad_control_required;
struct reset_control *rst;
+ struct pinctrl *pinctrl_sdmmc;
+ struct pinctrl_state *pinctrl_state_3v3;
+ struct pinctrl_state *pinctrl_state_1v8;
};
static u16 tegra_sdhci_readw(struct sdhci_host *host, int reg)
@@ -286,14 +292,80 @@ static int tegra_sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
return mmc_send_tuning(host->mmc, opcode, NULL);
}
-static void tegra_sdhci_voltage_switch(struct sdhci_host *host)
+static int tegra_sdhci_set_padctrl(struct sdhci_host *host, int voltage)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
- const struct sdhci_tegra_soc_data *soc_data = tegra_host->soc_data;
+ int ret;
+
+ if (!tegra_host->pad_control_required)
+ return 0;
+
+ if (voltage == MMC_SIGNAL_VOLTAGE_180) {
+ ret = pinctrl_select_state(tegra_host->pinctrl_sdmmc,
+ tegra_host->pinctrl_state_1v8);
+ if (ret < 0)
+ dev_err(mmc_dev(host->mmc),
+ "setting 1.8V failed, ret: %d\n", ret);
+ } else {
+ ret = pinctrl_select_state(tegra_host->pinctrl_sdmmc,
+ tegra_host->pinctrl_state_3v3);
+ if (ret < 0)
+ dev_err(mmc_dev(host->mmc),
+ "setting 3.3V failed, ret: %d\n", ret);
+ }
- if (soc_data->nvquirks & NVQUIRK_HAS_PADCALIB)
- tegra_host->pad_calib_required = true;
+ return ret;
+}
+
+static int sdhci_tegra_start_signal_voltage_switch(struct mmc_host *mmc,
+ struct mmc_ios *ios)
+{
+ struct sdhci_host *host = mmc_priv(mmc);
+ int ret = 0;
+
+ if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330) {
+ ret = tegra_sdhci_set_padctrl(host, ios->signal_voltage);
+ if (ret < 0)
+ return ret;
+ ret = sdhci_start_signal_voltage_switch(mmc, ios);
+ } else if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180) {
+ ret = sdhci_start_signal_voltage_switch(mmc, ios);
+ if (ret < 0)
+ return ret;
+ ret = tegra_sdhci_set_padctrl(host, ios->signal_voltage);
+ }
+
+ return ret;
+}
+
+static void tegra_sdhci_init_pinctrl_info(struct device *dev,
+ struct sdhci_tegra *tegra_host)
+{
+ tegra_host->pinctrl_sdmmc = devm_pinctrl_get(dev);
+ if (IS_ERR_OR_NULL(tegra_host->pinctrl_sdmmc)) {
Can this ever return NULL, considering ARCH_TEGRA selects PINCTRL?
IS_ERR is probably better. Same for the two other checks in this function.
+ dev_dbg(dev, "No pinctrl info, err: %ld\n",
+ PTR_ERR(tegra_host->pinctrl_sdmmc));
+ return;
+ }
+
+ tegra_host->pinctrl_state_3v3 =
+ pinctrl_lookup_state(tegra_host->pinctrl_sdmmc, "sdmmc-3v3");
+ if (IS_ERR_OR_NULL(tegra_host->pinctrl_state_3v3)) {
+ dev_err(dev, "Missing 3.3V pad state, err: %ld\n",
+ PTR_ERR(tegra_host->pinctrl_state_3v3));
+ return;
+ }
+
+ tegra_host->pinctrl_state_1v8 =
+ pinctrl_lookup_state(tegra_host->pinctrl_sdmmc, "sdmmc-1v8");
+ if (IS_ERR_OR_NULL(tegra_host->pinctrl_state_1v8)) {
+ dev_err(dev, "Missing 1.8V pad state, err: %ld\n",
+ PTR_ERR(tegra_host->pinctrl_state_3v3));
+ return;
+ }
+
+ tegra_host->pad_control_required = true; > }
static const struct sdhci_ops tegra_sdhci_ops = {
@@ -305,7 +377,6 @@ static const struct sdhci_ops tegra_sdhci_ops = {
.reset = tegra_sdhci_reset,
.platform_execute_tuning = tegra_sdhci_execute_tuning,
.set_uhs_signaling = tegra_sdhci_set_uhs_signaling,
- .voltage_switch = tegra_sdhci_voltage_switch,
.get_max_clock = tegra_sdhci_get_max_clock,
};
@@ -362,7 +433,6 @@ static const struct sdhci_ops tegra114_sdhci_ops = {
.reset = tegra_sdhci_reset,
.platform_execute_tuning = tegra_sdhci_execute_tuning,
.set_uhs_signaling = tegra_sdhci_set_uhs_signaling,
- .voltage_switch = tegra_sdhci_voltage_switch,
.get_max_clock = tegra_sdhci_get_max_clock,
};
@@ -419,6 +489,7 @@ static const struct sdhci_pltfm_data sdhci_tegra210_pdata = {
static const struct sdhci_tegra_soc_data soc_data_tegra210 = {
.pdata = &sdhci_tegra210_pdata,
+ .nvquirks = NVQUIRK_NEEDS_PAD_CONTROL,
};
static const struct sdhci_pltfm_data sdhci_tegra186_pdata = {
@@ -442,6 +513,7 @@ static const struct sdhci_pltfm_data sdhci_tegra186_pdata = {
static const struct sdhci_tegra_soc_data soc_data_tegra186 = {
.pdata = &sdhci_tegra186_pdata,
+ .nvquirks = NVQUIRK_NEEDS_PAD_CONTROL,
};
static const struct of_device_id sdhci_tegra_dt_match[] = {
@@ -478,8 +550,15 @@ static int sdhci_tegra_probe(struct platform_device *pdev)
tegra_host = sdhci_pltfm_priv(pltfm_host);
tegra_host->ddr_signaling = false;
tegra_host->pad_calib_required = false;
+ tegra_host->pad_control_required = false;
tegra_host->soc_data = soc_data;
+ if (soc_data->nvquirks & NVQUIRK_NEEDS_PAD_CONTROL) {
+ host->mmc_host_ops.start_signal_voltage_switch =
+ sdhci_tegra_start_signal_voltage_switch;
+ tegra_sdhci_init_pinctrl_info(&pdev->dev, tegra_host);
+ }
+
Do we know here if the controller is for eMMC or SD? If it's for SD we
should probably print a warning if the pinctrl info is not available.
Later we would also need to disable 1.8V modes if we fail to get the
pinctrl info.
Cheers,
Mikko
rc = mmc_of_parse(host->mmc);
if (rc)
goto err_parse_dt;