[PATCH 2/3] mmc: sdhci_am654: Update OTAPDLY writes

From: Faiz Abbas
Date: Wed Jan 08 2020 - 10:08:05 EST

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In reply to: Rob Herring: "Re: [PATCH 1/3] dt-bindings: mmc: sdhci-am654: Update Output tap delay binding"
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According to the latest AM65x Data Manual[1], a different output tap
delay value is optimum for a given speed mode. Therefore, deprecate the
ti,otap-del-sel binding and introduce a new binding for each of the
possible MMC/SD speed modes. If the legacy mode is not found, fall back
to old binding to maintain dts compatibility.

[1] http://www.ti.com/lit/gpn/am6526

Signed-off-by: Faiz Abbas <faiz_abbas@xxxxxx>
---
drivers/mmc/host/sdhci_am654.c | 123 ++++++++++++++++++++++++++++-----
include/linux/mmc/host.h | 2 +
2 files changed, 107 insertions(+), 18 deletions(-)

diff --git a/drivers/mmc/host/sdhci_am654.c b/drivers/mmc/host/sdhci_am654.c
index b8fe94fd9525..bb977de43f7d 100644
--- a/drivers/mmc/host/sdhci_am654.c
+++ b/drivers/mmc/host/sdhci_am654.c
@@ -81,7 +81,8 @@ static struct regmap_config sdhci_am654_regmap_config = {

struct sdhci_am654_data {
struct regmap *base;
- int otap_del_sel;
+ bool legacy_otapdly;
+ int otap_del_sel[11];
int trm_icp;
int drv_strength;
bool dll_on;
@@ -98,11 +99,34 @@ struct sdhci_am654_driver_data {
#define DLL_PRESENT (1 << 3)
};

+struct timing_data {
+ const char *binding;
+ u32 capability;
+};
+
+static const struct timing_data td[] = {
+ [MMC_TIMING_LEGACY] = {"ti,otap-del-sel-legacy", 0},
+ [MMC_TIMING_MMC_HS] = {"ti,otap-del-sel-mmc-hs", MMC_CAP_MMC_HIGHSPEED},
+ [MMC_TIMING_SD_HS] = {"ti,otap-del-sel-sd-hs", MMC_CAP_SD_HIGHSPEED},
+ [MMC_TIMING_UHS_SDR12] = {"ti,otap-del-sel-sdr12", MMC_CAP_UHS_SDR12},
+ [MMC_TIMING_UHS_SDR25] = {"ti,otap-del-sel-sdr25", MMC_CAP_UHS_SDR25},
+ [MMC_TIMING_UHS_SDR50] = {"ti,otap-del-sel-sdr50", MMC_CAP_UHS_SDR50},
+ [MMC_TIMING_UHS_SDR104] = {"ti,otap-del-sel-sdr104",
+ MMC_CAP_UHS_SDR104},
+ [MMC_TIMING_UHS_DDR50] = {"ti,otap-del-sel-ddr50", MMC_CAP_UHS_DDR50},
+ [MMC_TIMING_MMC_DDR52] = {"ti,otap-del-sel-ddr52", MMC_CAP_DDR},
+ [MMC_TIMING_MMC_HS200] = {"ti,otap-del-sel-hs200", MMC_CAP2_HS200},
+ [MMC_TIMING_MMC_HS400] = {"ti,otap-del-sel-hs400", MMC_CAP2_HS400},
+};
+
static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
+ unsigned char timing = host->mmc->ios.timing;
int sel50, sel100, freqsel;
+ u32 otap_del_sel;
+ u32 otap_del_ena;
u32 mask, val;
int ret;

@@ -116,22 +140,29 @@ static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)

if (clock > CLOCK_TOO_SLOW_HZ) {
/* Setup DLL Output TAP delay */
+ if (sdhci_am654->legacy_otapdly)
+ otap_del_sel = sdhci_am654->otap_del_sel[0];
+ else
+ otap_del_sel = sdhci_am654->otap_del_sel[timing];
+
+ otap_del_ena = (timing > MMC_TIMING_UHS_SDR25) ? 1 : 0;
+
mask = OTAPDLYENA_MASK | OTAPDLYSEL_MASK;
- val = (1 << OTAPDLYENA_SHIFT) |
- (sdhci_am654->otap_del_sel << OTAPDLYSEL_SHIFT);
- regmap_update_bits(sdhci_am654->base, PHY_CTRL4, mask, val);
+ val = (otap_del_ena << OTAPDLYENA_SHIFT) |
+ (otap_del_sel << OTAPDLYSEL_SHIFT);
+
/* Write to STRBSEL for HS400 speed mode */
- if (host->mmc->ios.timing == MMC_TIMING_MMC_HS400) {
+ if (timing == MMC_TIMING_MMC_HS400) {
if (sdhci_am654->flags & STRBSEL_4_BIT)
- mask = STRBSEL_4BIT_MASK;
+ mask |= STRBSEL_4BIT_MASK;
else
- mask = STRBSEL_8BIT_MASK;
+ mask |= STRBSEL_8BIT_MASK;

- regmap_update_bits(sdhci_am654->base, PHY_CTRL4, mask,
- sdhci_am654->strb_sel <<
- STRBSEL_SHIFT);
+ val |= sdhci_am654->strb_sel << STRBSEL_SHIFT;
}

+ regmap_update_bits(sdhci_am654->base, PHY_CTRL4, mask, val);
+
if (sdhci_am654->flags & FREQSEL_2_BIT) {
switch (clock) {
case 200000000:
@@ -198,11 +229,19 @@ static void sdhci_j721e_4bit_set_clock(struct sdhci_host *host,
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
- int val, mask;
+ unsigned char timing = host->mmc->ios.timing;
+ u32 otap_del_sel;
+ u32 mask, val;
+
+ /* Setup DLL Output TAP delay */
+ if (sdhci_am654->legacy_otapdly)
+ otap_del_sel = sdhci_am654->otap_del_sel[0];
+ else
+ otap_del_sel = sdhci_am654->otap_del_sel[timing];

mask = OTAPDLYENA_MASK | OTAPDLYSEL_MASK;
- val = (1 << OTAPDLYENA_SHIFT) |
- (sdhci_am654->otap_del_sel << OTAPDLYSEL_SHIFT);
+ val = (0x1 << OTAPDLYENA_SHIFT) |
+ (otap_del_sel << OTAPDLYSEL_SHIFT);
regmap_update_bits(sdhci_am654->base, PHY_CTRL4, mask, val);

sdhci_set_clock(host, clock);
@@ -371,6 +410,55 @@ static int sdhci_am654_cqe_add_host(struct sdhci_host *host)
return ret;
}

+static int sdhci_am654_get_otap_delay(struct sdhci_host *host,
+ struct sdhci_am654_data *sdhci_am654)
+{
+ struct device *dev = mmc_dev(host->mmc);
+ int i;
+ int ret;
+
+ ret = device_property_read_u32(dev, td[MMC_TIMING_LEGACY].binding,
+ &sdhci_am654->otap_del_sel[MMC_TIMING_LEGACY]);
+ if (ret) {
+ /*
+ * ti,otap-del-sel-legacy is mandatory, look for old binding
+ * if not found.
+ */
+ ret = device_property_read_u32(dev, "ti,otap-del-sel",
+ &sdhci_am654->otap_del_sel[0]);
+ if (ret) {
+ dev_err(dev, "Couldn't find otap-del-sel\n");
+
+ return ret;
+ }
+
+ dev_info(dev, "Using legacy binding ti,otap-del-sel\n");
+ sdhci_am654->legacy_otapdly = true;
+
+ return 0;
+ }
+
+ for (i = MMC_TIMING_MMC_HS; i <= MMC_TIMING_MMC_HS400; i++) {
+
+ ret = device_property_read_u32(dev, td[i].binding,
+ &sdhci_am654->otap_del_sel[i]);
+ if (ret) {
+ dev_dbg(dev, "Couldn't find %s\n",
+ td[i].binding);
+ /*
+ * Remove the corresponding capability
+ * if an otap-del-sel value is not found
+ */
+ if (i <= MMC_TIMING_MMC_DDR52)
+ host->mmc->caps &= ~td[i].capability;
+ else
+ host->mmc->caps2 &= ~td[i].capability;
+ }
+ }
+
+ return 0;
+}
+
static int sdhci_am654_init(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -419,6 +507,10 @@ static int sdhci_am654_init(struct sdhci_host *host)
if (ret)
goto err_cleanup_host;

+ ret = sdhci_am654_get_otap_delay(host, sdhci_am654);
+ if (ret)
+ goto err_cleanup_host;
+
ret = __sdhci_add_host(host);
if (ret)
goto err_cleanup_host;
@@ -437,11 +529,6 @@ static int sdhci_am654_get_of_property(struct platform_device *pdev,
int drv_strength;
int ret;

- ret = device_property_read_u32(dev, "ti,otap-del-sel",
- &sdhci_am654->otap_del_sel);
- if (ret)
- return ret;
-
if (sdhci_am654->flags & DLL_PRESENT) {
ret = device_property_read_u32(dev, "ti,trm-icp",
&sdhci_am654->trm_icp);
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index ba703384bea0..a22a10456c62 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -322,6 +322,8 @@ struct mmc_host {
#define MMC_CAP_3_3V_DDR (1 << 11) /* Host supports eMMC DDR 3.3V */
#define MMC_CAP_1_8V_DDR (1 << 12) /* Host supports eMMC DDR 1.8V */
#define MMC_CAP_1_2V_DDR (1 << 13) /* Host supports eMMC DDR 1.2V */
+#define MMC_CAP_DDR (MMC_CAP_3_3V_DDR | MMC_CAP_1_8V_DDR | \
+ MMC_CAP_1_2V_DDR)
#define MMC_CAP_POWER_OFF_CARD (1 << 14) /* Can power off after boot */
#define MMC_CAP_BUS_WIDTH_TEST (1 << 15) /* CMD14/CMD19 bus width ok */
#define MMC_CAP_UHS_SDR12 (1 << 16) /* Host supports UHS SDR12 mode */
--
2.19.2

Next message: Faiz Abbas: "[PATCH 3/3] mmc: sdhci_am654: Enable DLL only for some speed modes"
Previous message: Faiz Abbas: "[PATCH 1/3] dt-bindings: mmc: sdhci-am654: Update Output tap delay binding"
In reply to: Rob Herring: "Re: [PATCH 1/3] dt-bindings: mmc: sdhci-am654: Update Output tap delay binding"
Next in thread: Faiz Abbas: "[PATCH 3/3] mmc: sdhci_am654: Enable DLL only for some speed modes"
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