[U-Boot] [PATCH V4 4/9] EXYNOS5: DWMMC: Added FDT support for DWMMC

Amar amarendra.xt at samsung.com
Fri Jan 4 10:34:05 CET 2013


This patch adds FDT support for DWMMC, by reading the DWMMC node data
from the device tree and initialising DWMMC channels as per data
obtained from the node.

Changes from V1:
        1)Updated code to have same signature for the function
        exynos_dwmci_init() for both FDT and non-FDT versions.
        2)Updated code to pass device_id parameter to the function
        exynos5_mmc_set_clk_div() instead of index.
        3)Updated code to decode the value of "samsung,width" from FDT.
        4)Channel index is computed instead of getting from FDT.

Changes from V2:
        1)Updation of commit message and resubmition of proper patch set.

Changes from V3:
	1)Replaced the new function exynos5_mmc_set_clk_div() with the
	existing function set_mmc_clk(). set_mmc_clk() will do the purpose.
	2)Computation of FSYS block clock divisor (pre-ratio) is added.

Signed-off-by: Vivek Gautam <gautam.vivek at samsung.com>
Signed-off-by: Amar <amarendra.xt at samsung.com>
---
 arch/arm/include/asm/arch-exynos/dwmmc.h |   4 +
 drivers/mmc/exynos_dw_mmc.c              | 129 +++++++++++++++++++++++++++++--
 include/dwmmc.h                          |   4 +
 3 files changed, 130 insertions(+), 7 deletions(-)

diff --git a/arch/arm/include/asm/arch-exynos/dwmmc.h b/arch/arm/include/asm/arch-exynos/dwmmc.h
index 8acdf9b..40dcc7b 100644
--- a/arch/arm/include/asm/arch-exynos/dwmmc.h
+++ b/arch/arm/include/asm/arch-exynos/dwmmc.h
@@ -29,8 +29,12 @@
 
 int exynos_dwmci_init(u32 regbase, int bus_width, int index);
 
+#ifdef CONFIG_OF_CONTROL
+unsigned int exynos_dwmmc_init(const void *blob);
+#else
 static inline unsigned int exynos_dwmmc_init(int index, int bus_width)
 {
 	unsigned int base = samsung_get_base_mmc() + (0x10000 * index);
 	return exynos_dwmci_init(base, bus_width, index);
 }
+#endif
diff --git a/drivers/mmc/exynos_dw_mmc.c b/drivers/mmc/exynos_dw_mmc.c
index 72a31b7..d7ca7d0 100644
--- a/drivers/mmc/exynos_dw_mmc.c
+++ b/drivers/mmc/exynos_dw_mmc.c
@@ -19,39 +19,154 @@
  */
 
 #include <common.h>
-#include <malloc.h>
 #include <dwmmc.h>
+#include <fdtdec.h>
+#include <libfdt.h>
+#include <malloc.h>
 #include <asm/arch/dwmmc.h>
 #include <asm/arch/clk.h>
+#include <asm/arch/pinmux.h>
+
+#define	DWMMC_MAX_CH_NUM		4
+#define	DWMMC_MAX_FREQ			52000000
+#define	DWMMC_MIN_FREQ			400000
+#define	DWMMC_MMC0_CLKSEL_VAL		0x03030001
+#define	DWMMC_MMC2_CLKSEL_VAL		0x03020001
+#define	ONE_MEGA_HZ			1000000
+#define	SCALED_VAL_FOUR_HUNDRED		400
 
 static char *EXYNOS_NAME = "EXYNOS DWMMC";
+u32 timing[3];
 
+/*
+ * Function used as callback function to initialise the
+ * CLKSEL register for every mmc channel.
+ */
 static void exynos_dwmci_clksel(struct dwmci_host *host)
 {
-	u32 val;
-	val = DWMCI_SET_SAMPLE_CLK(DWMCI_SHIFT_0) |
-		DWMCI_SET_DRV_CLK(DWMCI_SHIFT_0) | DWMCI_SET_DIV_RATIO(0);
+	dwmci_writel(host, DWMCI_CLKSEL, host->clksel_val);
+}
 
-	dwmci_writel(host, DWMCI_CLKSEL, val);
+unsigned int exynos_dwmci_get_clk(int dev_index)
+{
+	return get_mmc_clk(dev_index);
 }
 
 int exynos_dwmci_init(u32 regbase, int bus_width, int index)
 {
 	struct dwmci_host *host = NULL;
+	unsigned int clock, div;
 	host = malloc(sizeof(struct dwmci_host));
 	if (!host) {
 		printf("dwmci_host malloc fail!\n");
 		return 1;
 	}
 
+	/*
+	 * The max operating freq of FSYS block is 400MHz.
+	 * Scale down the 400MHz to number 400.
+	 * Scale down the MPLL clock by dividing MPLL_CLK with ONE_MEGA_HZ.
+	 * Arrive at the divisor value taking 400 as the reference.
+	 */
+
+	/* get mpll clock and divide it by ONE_MEGA_HZ */
+	clock = get_pll_clk(MPLL) / ONE_MEGA_HZ;
+
+	/* Arrive at the divisor value. */
+	for (div = 0; div <= 0xf; div++) {
+		if ((clock / (div + 1)) <= SCALED_VAL_FOUR_HUNDRED)
+			break;
+	}
+
+	/* set the clock divisor for mmc */
+	set_mmc_clk(index, div);
+
 	host->name = EXYNOS_NAME;
 	host->ioaddr = (void *)regbase;
 	host->buswidth = bus_width;
+#ifdef CONFIG_OF_CONTROL
+	host->clksel_val = (DWMCI_SET_SAMPLE_CLK(timing[0]) |
+				DWMCI_SET_DRV_CLK(timing[1]) |
+				DWMCI_SET_DIV_RATIO(timing[2]));
+#else
+	if (0 == index)
+		host->clksel_val = DWMMC_MMC0_CLKSEL_VAL;
+	if (2 == index)
+		host->clksel_val = DWMMC_MMC2_CLKSEL_VAL;
+#endif
 	host->clksel = exynos_dwmci_clksel;
 	host->dev_index = index;
-
-	add_dwmci(host, 52000000, 400000);
+	host->mmc_clk = exynos_dwmci_get_clk;
+	/* Add the mmc chennel to be registered with mmc core */
+	add_dwmci(host, DWMMC_MAX_FREQ, DWMMC_MIN_FREQ);
 
 	return 0;
 }
 
+#ifdef CONFIG_OF_CONTROL
+unsigned int exynos_dwmmc_init(const void *blob)
+{
+	u32 base;
+	int index, bus_width;
+	int node_list[DWMMC_MAX_CH_NUM];
+	int err = 0;
+	int dev_id, flag;
+	int count, i;
+
+	count = fdtdec_find_aliases_for_id(blob, "dwmmc",
+				COMPAT_SAMSUNG_EXYNOS5_DWMMC, node_list,
+				DWMMC_MAX_CH_NUM);
+
+	for (i = 0; i < count; i++) {
+		int node = node_list[i];
+
+		if (node <= 0)
+			continue;
+
+		/* Extract device id for each mmc channel */
+		dev_id = pinmux_decode_periph_id(blob, node);
+
+		/* Get the bus width from the device node */
+		bus_width = fdtdec_get_int(blob, node, "samsung,bus-width", 0);
+		if (bus_width < 0) {
+			debug("DWMMC: Can't get bus-width\n");
+			return -1;
+		}
+		if (8 == bus_width)
+			flag = PINMUX_FLAG_8BIT_MODE;
+		else
+			flag = PINMUX_FLAG_NONE;
+
+		/* config pinmux for each mmc channel */
+		err = exynos_pinmux_config(dev_id, flag);
+		if (err) {
+			debug("DWMMC not configured\n");
+			return err;
+		}
+
+		index = dev_id - PERIPH_ID_SDMMC0;
+
+		/* Get the base address from the device node */
+		base = fdtdec_get_addr(blob, node, "reg");
+		if (!base) {
+			debug("DWMMC: Can't get base address\n");
+			return -1;
+		}
+		/* Extract the timing info from the node */
+		err = fdtdec_get_int_array(blob, node, "samsung,timing",
+					timing, 3);
+		if (err) {
+			debug("Can't get sdr-timings for divider\n");
+			return -1;
+		}
+		/* Initialise each mmc channel */
+		err =  exynos_dwmci_init(base, bus_width, index);
+		if (err) {
+			debug("Can't do dwmci init\n");
+			return -1;
+		}
+	}
+
+	return 0;
+}
+#endif
diff --git a/include/dwmmc.h b/include/dwmmc.h
index c8b1d40..4a42849 100644
--- a/include/dwmmc.h
+++ b/include/dwmmc.h
@@ -123,6 +123,9 @@
 #define MSIZE(x)		((x) << 28)
 #define RX_WMARK(x)		((x) << 16)
 #define TX_WMARK(x)		(x)
+#define RX_WMARK_SHIFT		16
+#define RX_WMARK_MASK		(0xfff << RX_WMARK_SHIFT)
+
 
 #define DWMCI_IDMAC_OWN		(1 << 31)
 #define DWMCI_IDMAC_CH		(1 << 4)
@@ -144,6 +147,7 @@ struct dwmci_host {
 	unsigned int bus_hz;
 	int dev_index;
 	int buswidth;
+	u32 clksel_val;
 	u32 fifoth_val;
 	struct mmc *mmc;
 
-- 
1.8.0



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