mmc: tegra: port to standard clock/reset APIs

Tegra186 supports the new standard clock and reset APIs. Older Tegra SoCs
still use custom APIs. Enhance the Tegra MMC driver so that it can operate
with either set of APIs.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>

arch/arm/include/asm/arch-tegra/tegra_mmc.h

@@ -9,6 +9,9 @@
 #ifndef __TEGRA_MMC_H_
 #define __TEGRA_MMC_H_
 
+#include <common.h>
+#include <clk.h>
+#include <reset.h>
 #include <fdtdec.h>
 #include <asm/gpio.h>
 
@@ -134,7 +137,10 @@ struct mmc_host {
 	int id;			/* device id/number, 0-3 */
 	int enabled;		/* 1 to enable, 0 to disable */
 	int width;		/* Bus Width, 1, 4 or 8 */
-#ifndef CONFIG_TEGRA186
+#ifdef CONFIG_TEGRA186
+	struct reset_ctl reset_ctl;
+	struct clk clk;
+#else
 	enum periph_id mmc_id;	/* Peripheral ID: PERIPH_ID_... */
 #endif
 	struct gpio_desc cd_gpio;	/* Change Detect GPIO */

drivers/mmc/tegra_mmc.c

@@ -9,6 +9,7 @@
 
 #include <bouncebuf.h>
 #include <common.h>
+#include <dm/device.h>
 #include <errno.h>
 #include <asm/gpio.h>
 #include <asm/io.h>
@@ -20,6 +21,15 @@
 #include <asm/arch-tegra/tegra_mmc.h>
 #include <mmc.h>
 
+/*
+ * FIXME: TODO: This driver contains a number of ifdef CONFIG_TEGRA186 that
+ * should not be present. These are needed because newer Tegra SoCs support
+ * only the standard clock/reset APIs, whereas older Tegra SoCs support only
+ * a custom Tegra-specific API. ASAP the older Tegra SoCs' code should be
+ * fixed to implement the standard APIs, and all drivers converted to solely
+ * use the new standard APIs, with no ifdefs.
+ */
+
 DECLARE_GLOBAL_DATA_PTR;
 
 struct mmc_host mmc_host[CONFIG_SYS_MMC_MAX_DEVICE];
@@ -360,11 +370,14 @@ static void mmc_change_clock(struct mmc_host *host, uint clock)
 	 */
 	if (clock == 0)
 		goto out;
-#ifndef CONFIG_TEGRA186
+#ifdef CONFIG_TEGRA186
+	{
+		ulong rate = clk_set_rate(&host->clk, clock);
+		div = (rate + clock - 1) / clock;
+	}
+#else
 	clock_adjust_periph_pll_div(host->mmc_id, CLOCK_ID_PERIPH, clock,
 				    &div);
-#else
-	div = (20000000 + clock - 1) / clock;
 #endif
 	debug("div = %d\n", div);
 
@@ -539,6 +552,9 @@ static int do_mmc_init(int dev_index, bool removable)
 {
 	struct mmc_host *host;
 	struct mmc *mmc;
+#ifdef CONFIG_TEGRA186
+	int ret;
+#endif
 
 	/* DT should have been read & host config filled in */
 	host = &mmc_host[dev_index];
@@ -550,7 +566,21 @@ static int do_mmc_init(int dev_index, bool removable)
 	      gpio_get_number(&host->cd_gpio));
 
 	host->clock = 0;
-#ifndef CONFIG_TEGRA186
+
+#ifdef CONFIG_TEGRA186
+	ret = reset_assert(&host->reset_ctl);
+	if (ret)
+		return ret;
+	ret = clk_enable(&host->clk);
+	if (ret)
+		return ret;
+	ret = clk_set_rate(&host->clk, 20000000);
+	if (IS_ERR_VALUE(ret))
+		return ret;
+	ret = reset_deassert(&host->reset_ctl);
+	if (ret)
+		return ret;
+#else
 	clock_start_periph_pll(host->mmc_id, CLOCK_ID_PERIPH, 20000000);
 #endif
 
@@ -577,11 +607,7 @@ static int do_mmc_init(int dev_index, bool removable)
 	 *  (actually 52MHz)
 	 */
 	host->cfg.f_min = 375000;
-#ifndef CONFIG_TEGRA186
 	host->cfg.f_max = 48000000;
-#else
-	host->cfg.f_max = 375000;
-#endif
 
 	host->cfg.b_max = CONFIG_SYS_MMC_MAX_BLK_COUNT;
 
@@ -613,7 +639,27 @@ static int mmc_get_config(const void *blob, int node, struct mmc_host *host,
 		return -FDT_ERR_NOTFOUND;
 	}
 
-#ifndef CONFIG_TEGRA186
+#ifdef CONFIG_TEGRA186
+	{
+		/*
+		 * FIXME: This variable should go away when the MMC device
+		 * actually is a udevice.
+		 */
+		struct udevice dev;
+		int ret;
+		dev.of_offset = node;
+		ret = reset_get_by_name(&dev, "sdmmc", &host->reset_ctl);
+		if (ret) {
+			debug("reset_get_by_index() failed: %d\n", ret);
+			return ret;
+		}
+		ret = clk_get_by_name(&dev, "sdmmc", &host->clk);
+		if (ret) {
+			debug("clk_get_by_index() failed: %d\n", ret);
+			return ret;
+		}
+	}
+#else
 	host->mmc_id = clock_decode_periph_id(blob, node);
 	if (host->mmc_id == PERIPH_ID_NONE) {
 		debug("%s: could not decode periph id\n", __func__);