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Subject[PATCH v2 06/16] mmc: sdhci_omap: Add support to set IODELAY values
Date
The data manual of J6/J6 Eco recommends to set different IODELAY values
depending on the mode in which the MMC/SD is enumerated in order to
ensure IO timings are met.

Add support to set the IODELAY values depending on the various MMC
modes using the pinctrl APIs.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
drivers/mmc/host/sdhci-omap.c | 147 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 147 insertions(+)

diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c
index e24ae903f7ba..8b6170cd689b 100644
--- a/drivers/mmc/host/sdhci-omap.c
+++ b/drivers/mmc/host/sdhci-omap.c
@@ -90,8 +90,12 @@

#define MAX_PHASE_DELAY 0x7C

+/* sdhci-omap controller flags */
+#define SDHCI_OMAP_REQUIRE_IODELAY BIT(0)
+
struct sdhci_omap_data {
u32 offset;
+ u8 flags;
};

struct sdhci_omap_host {
@@ -102,8 +106,16 @@ struct sdhci_omap_host {
struct sdhci_host *host;
u8 bus_mode;
u8 power_mode;
+ u8 timing;
+ u8 flags;
+
+ struct pinctrl *pinctrl;
+ struct pinctrl_state **pinctrl_state;
};

+static void sdhci_omap_start_clock(struct sdhci_omap_host *omap_host);
+static void sdhci_omap_stop_clock(struct sdhci_omap_host *omap_host);
+
static inline u32 sdhci_omap_readl(struct sdhci_omap_host *host,
unsigned int offset)
{
@@ -436,6 +448,31 @@ static int sdhci_omap_start_signal_voltage_switch(struct mmc_host *mmc,
return 0;
}

+static void sdhci_omap_set_timing(struct sdhci_omap_host *omap_host, u8 timing)
+{
+ int ret;
+ struct pinctrl_state *pinctrl_state;
+ struct device *dev = omap_host->dev;
+
+ if (!(omap_host->flags & SDHCI_OMAP_REQUIRE_IODELAY))
+ return;
+
+ if (omap_host->timing == timing)
+ return;
+
+ sdhci_omap_stop_clock(omap_host);
+
+ pinctrl_state = omap_host->pinctrl_state[timing];
+ ret = pinctrl_select_state(omap_host->pinctrl, pinctrl_state);
+ if (ret) {
+ dev_err(dev, "failed to select pinctrl state\n");
+ return;
+ }
+
+ sdhci_omap_start_clock(omap_host);
+ omap_host->timing = timing;
+}
+
static void sdhci_omap_set_power_mode(struct sdhci_omap_host *omap_host,
u8 power_mode)
{
@@ -472,6 +509,7 @@ static void sdhci_omap_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
omap_host = sdhci_pltfm_priv(pltfm_host);

sdhci_omap_set_bus_mode(omap_host, ios->bus_mode);
+ sdhci_omap_set_timing(omap_host, ios->timing);
sdhci_set_ios(mmc, ios);
sdhci_omap_set_power_mode(omap_host, ios->power_mode);
}
@@ -680,6 +718,7 @@ static const struct sdhci_pltfm_data sdhci_omap_pdata = {

static const struct sdhci_omap_data dra7_data = {
.offset = 0x200,
+ .flags = SDHCI_OMAP_REQUIRE_IODELAY,
};

static const struct of_device_id omap_sdhci_match[] = {
@@ -688,6 +727,108 @@ static const struct of_device_id omap_sdhci_match[] = {
};
MODULE_DEVICE_TABLE(of, omap_sdhci_match);

+static struct pinctrl_state
+*sdhci_omap_iodelay_pinctrl_state(struct sdhci_omap_host *omap_host, char *mode,
+ u32 *caps, u32 capmask)
+{
+ struct device *dev = omap_host->dev;
+ struct pinctrl_state *pinctrl_state = ERR_PTR(-ENODEV);
+
+ if (!(*caps & capmask))
+ goto ret;
+
+ pinctrl_state = pinctrl_lookup_state(omap_host->pinctrl, mode);
+ if (IS_ERR(pinctrl_state)) {
+ dev_err(dev, "no pinctrl state for %s mode", mode);
+ *caps &= ~capmask;
+ }
+
+ret:
+ return pinctrl_state;
+}
+
+static int sdhci_omap_config_iodelay_pinctrl_state(struct sdhci_omap_host
+ *omap_host)
+{
+ struct device *dev = omap_host->dev;
+ struct sdhci_host *host = omap_host->host;
+ struct mmc_host *mmc = host->mmc;
+ u32 *caps = &mmc->caps;
+ u32 *caps2 = &mmc->caps2;
+ struct pinctrl_state *state;
+ struct pinctrl_state **pinctrl_state;
+
+ if (!(omap_host->flags & SDHCI_OMAP_REQUIRE_IODELAY))
+ return 0;
+
+ pinctrl_state = devm_kzalloc(dev, sizeof(*pinctrl_state) *
+ (MMC_TIMING_MMC_HS200 + 1), GFP_KERNEL);
+ if (!pinctrl_state)
+ return -ENOMEM;
+
+ omap_host->pinctrl = devm_pinctrl_get(omap_host->dev);
+ if (IS_ERR(omap_host->pinctrl)) {
+ dev_err(dev, "Cannot get pinctrl\n");
+ return PTR_ERR(omap_host->pinctrl);
+ }
+
+ state = pinctrl_lookup_state(omap_host->pinctrl, "default");
+ if (IS_ERR(state)) {
+ dev_err(dev, "no pinctrl state for default mode\n");
+ return PTR_ERR(state);
+ }
+ pinctrl_state[MMC_TIMING_LEGACY] = state;
+
+ state = sdhci_omap_iodelay_pinctrl_state(omap_host, "sdr104", caps,
+ MMC_CAP_UHS_SDR104);
+ if (!IS_ERR(state))
+ pinctrl_state[MMC_TIMING_UHS_SDR104] = state;
+
+ state = sdhci_omap_iodelay_pinctrl_state(omap_host, "ddr50", caps,
+ MMC_CAP_UHS_DDR50);
+ if (!IS_ERR(state))
+ pinctrl_state[MMC_TIMING_UHS_DDR50] = state;
+
+ state = sdhci_omap_iodelay_pinctrl_state(omap_host, "sdr50", caps,
+ MMC_CAP_UHS_SDR50);
+ if (!IS_ERR(state))
+ pinctrl_state[MMC_TIMING_UHS_SDR50] = state;
+
+ state = sdhci_omap_iodelay_pinctrl_state(omap_host, "sdr25", caps,
+ MMC_CAP_UHS_SDR25);
+ if (!IS_ERR(state))
+ pinctrl_state[MMC_TIMING_UHS_SDR25] = state;
+
+ state = sdhci_omap_iodelay_pinctrl_state(omap_host, "sdr12", caps,
+ MMC_CAP_UHS_SDR12);
+ if (!IS_ERR(state))
+ pinctrl_state[MMC_TIMING_UHS_SDR12] = state;
+
+ state = sdhci_omap_iodelay_pinctrl_state(omap_host, "ddr_1_8v", caps,
+ MMC_CAP_1_8V_DDR);
+ if (!IS_ERR(state))
+ pinctrl_state[MMC_TIMING_MMC_DDR52] = state;
+
+ state = sdhci_omap_iodelay_pinctrl_state(omap_host, "hs", caps,
+ MMC_CAP_SD_HIGHSPEED);
+ if (!IS_ERR(state))
+ pinctrl_state[MMC_TIMING_SD_HS] = state;
+
+ state = sdhci_omap_iodelay_pinctrl_state(omap_host, "hs", caps,
+ MMC_CAP_MMC_HIGHSPEED);
+ if (!IS_ERR(state))
+ pinctrl_state[MMC_TIMING_MMC_HS] = state;
+
+ state = sdhci_omap_iodelay_pinctrl_state(omap_host, "hs200_1_8v", caps2,
+ MMC_CAP2_HS200_1_8V_SDR);
+ if (!IS_ERR(state))
+ pinctrl_state[MMC_TIMING_MMC_HS200] = state;
+
+ omap_host->pinctrl_state = pinctrl_state;
+
+ return 0;
+}
+
static int sdhci_omap_probe(struct platform_device *pdev)
{
int ret;
@@ -724,6 +865,8 @@ static int sdhci_omap_probe(struct platform_device *pdev)
omap_host->base = host->ioaddr;
omap_host->dev = dev;
omap_host->power_mode = MMC_POWER_UNDEFINED;
+ omap_host->timing = MMC_TIMING_LEGACY;
+ omap_host->flags = data->flags;
host->ioaddr += offset;

mmc = host->mmc;
@@ -772,6 +915,10 @@ static int sdhci_omap_probe(struct platform_device *pdev)
goto err_put_sync;
}

+ ret = sdhci_omap_config_iodelay_pinctrl_state(omap_host);
+ if (ret)
+ goto err_put_sync;
+
host->mmc_host_ops.get_ro = mmc_gpio_get_ro;
host->mmc_host_ops.start_signal_voltage_switch =
sdhci_omap_start_signal_voltage_switch;
--
2.11.0
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