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path: root/drivers/mmc/host/sdhci-omap.c
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Diffstat (limited to 'drivers/mmc/host/sdhci-omap.c')
-rw-r--r--drivers/mmc/host/sdhci-omap.c90
1 files changed, 89 insertions, 1 deletions
diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c
index ecf905066c56..c11c18a9aacb 100644
--- a/drivers/mmc/host/sdhci-omap.c
+++ b/drivers/mmc/host/sdhci-omap.c
@@ -27,6 +27,7 @@
#include <linux/regulator/consumer.h>
#include <linux/pinctrl/consumer.h>
#include <linux/sys_soc.h>
+#include <linux/thermal.h>
#include "sdhci-pltfm.h"
@@ -290,15 +291,19 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode)
struct sdhci_host *host = mmc_priv(mmc);
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host);
+ struct thermal_zone_device *thermal_dev;
struct device *dev = omap_host->dev;
struct mmc_ios *ios = &mmc->ios;
u32 start_window = 0, max_window = 0;
+ bool single_point_failure = false;
bool dcrc_was_enabled = false;
u8 cur_match, prev_match = 0;
u32 length = 0, max_len = 0;
u32 phase_delay = 0;
+ int temperature;
int ret = 0;
u32 reg;
+ int i;
/* clock tuning is not needed for upto 52MHz */
if (ios->clock <= 52000000)
@@ -308,6 +313,16 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode)
if (ios->timing == MMC_TIMING_UHS_SDR50 && !(reg & CAPA2_TSDR50))
return 0;
+ thermal_dev = thermal_zone_get_zone_by_name("cpu_thermal");
+ if (IS_ERR(thermal_dev)) {
+ dev_err(dev, "Unable to get thermal zone for tuning\n");
+ return PTR_ERR(thermal_dev);
+ }
+
+ ret = thermal_zone_get_temp(thermal_dev, &temperature);
+ if (ret)
+ return ret;
+
reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_DLL);
reg |= DLL_SWT;
sdhci_omap_writel(omap_host, SDHCI_OMAP_DLL, reg);
@@ -325,6 +340,11 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode)
omap_host->is_tuning = true;
+ /*
+ * Stage 1: Search for a maximum pass window ignoring any
+ * any single point failures. If the tuning value ends up
+ * near it, move away from it in stage 2 below
+ */
while (phase_delay <= MAX_PHASE_DELAY) {
sdhci_omap_set_dll(omap_host, phase_delay);
@@ -332,10 +352,15 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode)
if (cur_match) {
if (prev_match) {
length++;
+ } else if (single_point_failure) {
+ /* ignore single point failure */
+ length++;
} else {
start_window = phase_delay;
length = 1;
}
+ } else {
+ single_point_failure = prev_match;
}
if (length > max_len) {
@@ -353,13 +378,76 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode)
goto tuning_error;
}
+ /*
+ * Assign tuning value as a ratio of maximum pass window based
+ * on temperature
+ */
+ if (temperature < -20000)
+ phase_delay = min(max_window + 4 * max_len - 24,
+ max_window +
+ DIV_ROUND_UP(13 * max_len, 16) * 4);
+ else if (temperature < 20000)
+ phase_delay = max_window + DIV_ROUND_UP(9 * max_len, 16) * 4;
+ else if (temperature < 40000)
+ phase_delay = max_window + DIV_ROUND_UP(8 * max_len, 16) * 4;
+ else if (temperature < 70000)
+ phase_delay = max_window + DIV_ROUND_UP(7 * max_len, 16) * 4;
+ else if (temperature < 90000)
+ phase_delay = max_window + DIV_ROUND_UP(5 * max_len, 16) * 4;
+ else if (temperature < 120000)
+ phase_delay = max_window + DIV_ROUND_UP(4 * max_len, 16) * 4;
+ else
+ phase_delay = max_window + DIV_ROUND_UP(3 * max_len, 16) * 4;
+
+ /*
+ * Stage 2: Search for a single point failure near the chosen tuning
+ * value in two steps. First in the +3 to +10 range and then in the
+ * +2 to -10 range. If found, move away from it in the appropriate
+ * direction by the appropriate amount depending on the temperature.
+ */
+ for (i = 3; i <= 10; i++) {
+ sdhci_omap_set_dll(omap_host, phase_delay + i);
+
+ if (mmc_send_tuning(mmc, opcode, NULL)) {
+ if (temperature < 10000)
+ phase_delay += i + 6;
+ else if (temperature < 20000)
+ phase_delay += i - 12;
+ else if (temperature < 70000)
+ phase_delay += i - 8;
+ else
+ phase_delay += i - 6;
+
+ goto single_failure_found;
+ }
+ }
+
+ for (i = 2; i >= -10; i--) {
+ sdhci_omap_set_dll(omap_host, phase_delay + i);
+
+ if (mmc_send_tuning(mmc, opcode, NULL)) {
+ if (temperature < 10000)
+ phase_delay += i + 12;
+ else if (temperature < 20000)
+ phase_delay += i + 8;
+ else if (temperature < 70000)
+ phase_delay += i + 8;
+ else if (temperature < 90000)
+ phase_delay += i + 10;
+ else
+ phase_delay += i + 12;
+
+ goto single_failure_found;
+ }
+ }
+
+single_failure_found:
reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_AC12);
if (!(reg & AC12_SCLK_SEL)) {
ret = -EIO;
goto tuning_error;
}
- phase_delay = max_window + 4 * (max_len >> 1);
sdhci_omap_set_dll(omap_host, phase_delay);
omap_host->is_tuning = false;