Patchwork [U-Boot,4/5] mmc: Tegra: Add SD bus power/voltage function and MMC pad init call.

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Submitter Tom Warren
Date Feb. 26, 2013, 8:46 p.m.
Message ID <1361911596-16518-5-git-send-email-twarren@nvidia.com>
Download mbox | patch
Permalink /patch/223392/
State Superseded
Delegated to: Tom Warren
Headers show

Comments

Tom Warren - Feb. 26, 2013, 8:46 p.m.
Tegra30 requires the SD Bus Voltage & Power bits be set in the SD
Power Control register. Tegra20 works w/o them set, but do it anyway
for those SoCs as it's part of the SD spec. Also call a common
board pad init routine (pad_init_mmc) in mmc_reset(), used by
Tegra30 only for now.

Signed-off-by: Tom Warren <twarren@nvidia.com>
---
 drivers/mmc/tegra_mmc.c |   48 ++++++++++++++++++++++++++++++++++++++++++----
 1 files changed, 43 insertions(+), 5 deletions(-)

Patch

diff --git a/drivers/mmc/tegra_mmc.c b/drivers/mmc/tegra_mmc.c
index 6063d08..9e44771 100644
--- a/drivers/mmc/tegra_mmc.c
+++ b/drivers/mmc/tegra_mmc.c
@@ -21,7 +21,6 @@ 
 
 #include <bouncebuf.h>
 #include <common.h>
-#include <fdtdec.h>
 #include <asm/gpio.h>
 #include <asm/io.h>
 #include <asm/arch/clock.h>
@@ -38,6 +37,38 @@  struct mmc_host mmc_host[MAX_HOSTS];
 #error "Please enable device tree support to use this driver"
 #endif
 
+static void mmc_set_power(struct mmc_host *host, unsigned short power)
+{
+	u8 pwr = 0;
+	debug("%s: power = %x\n", __func__, power);
+
+	if (power != (unsigned short)-1) {
+		switch (1 << power) {
+		case MMC_VDD_165_195:
+			pwr = TEGRA_MMC_PWRCTL_SD_BUS_VOLTAGE_V1_8;
+			break;
+		case MMC_VDD_29_30:
+		case MMC_VDD_30_31:
+			pwr = TEGRA_MMC_PWRCTL_SD_BUS_VOLTAGE_V3_0;
+			break;
+		case MMC_VDD_32_33:
+		case MMC_VDD_33_34:
+			pwr = TEGRA_MMC_PWRCTL_SD_BUS_VOLTAGE_V3_3;
+			break;
+		}
+	}
+	debug("%s: pwr = %X\n", __func__, pwr);
+
+	/* Set the bus voltage first (if any) */
+	writeb(pwr, &host->reg->pwrcon);
+	if (pwr == 0)
+		return;
+
+	/* Now enable bus power */
+	pwr |= TEGRA_MMC_PWRCTL_SD_BUS_POWER;
+	writeb(pwr, &host->reg->pwrcon);
+}
+
 static void mmc_prepare_data(struct mmc_host *host, struct mmc_data *data,
 				struct bounce_buffer *bbstate)
 {
@@ -334,8 +365,7 @@  static void mmc_change_clock(struct mmc_host *host, uint clock)
 	debug(" mmc_change_clock called\n");
 
 	/*
-	 * Change Tegra SDMMCx clock divisor here. Source is 216MHz,
-	 * PLLP_OUT0
+	 * Change Tegra SDMMCx clock divisor here. Source is PLLP_OUT0
 	 */
 	if (clock == 0)
 		goto out;
@@ -410,7 +440,7 @@  static void mmc_set_ios(struct mmc *mmc)
 	debug("mmc_set_ios: hostctl = %08X\n", ctrl);
 }
 
-static void mmc_reset(struct mmc_host *host)
+static void mmc_reset(struct mmc_host *host, struct mmc *mmc)
 {
 	unsigned int timeout;
 	debug(" mmc_reset called\n");
@@ -436,6 +466,14 @@  static void mmc_reset(struct mmc_host *host)
 		timeout--;
 		udelay(1000);
 	}
+
+	/* Set SD bus voltage & enable bus power */
+	mmc_set_power(host, fls(mmc->voltages) - 1);
+	debug("%s: power control = %02X, host control = %02X\n", __func__,
+		readb(&host->reg->pwrcon), readb(&host->reg->hostctl));
+
+	/* Make sure SDIO pads are set up */
+	pad_init_mmc(host->reg);
 }
 
 static int mmc_core_init(struct mmc *mmc)
@@ -444,7 +482,7 @@  static int mmc_core_init(struct mmc *mmc)
 	unsigned int mask;
 	debug(" mmc_core_init called\n");
 
-	mmc_reset(host);
+	mmc_reset(host, mmc);
 
 	host->version = readw(&host->reg->hcver);
 	debug("host version = %x\n", host->version);