[U-Boot] [PATCH V7 04/10] EXYNOS5: DWMMC: Added FDT support for DWMMC

Amar amarendra.xt at samsung.com
Tue Mar 5 14:11:24 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.

Signed-off-by: Vivek Gautam <gautam.vivek at samsung.com>
Signed-off-by: Amar <amarendra.xt at samsung.com>
Acked-by: Simon Glass <sjg at chromium.org>
---
Changes since 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 since V2:
	1)Updation of commit message and resubmition of proper patch set.

Changes since 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.

Changes since V4:
	1)Replaced "unsigned int exynos_dwmmc_init(int index, int bus_width)" with
	int exynos_dwmci_add_port(int, u32, inth, u32)
		i)exynos_dwmmc_add_port() will be used by non-FDT boards.
		ii)In FDT case, exynos_dwmmc_init(const void *blob) will use
		exynos_dwmmc_add_port() for every channel enabled in device node.
	2)Changed the computation method of mmc clock divisor.
	3)Updated exynos_dwmmc_init() to compute the 'clksel_val' within the function.

Changes since V5:
	1)Updated in response to review comments and changed the mmc clock value
	from 50MHz to 52MHz.

Changes since V6:
	No change.

 arch/arm/include/asm/arch-exynos/dwmmc.h |  11 +--
 drivers/mmc/exynos_dw_mmc.c              | 127 ++++++++++++++++++++++++++++---
 include/dwmmc.h                          |   3 +
 3 files changed, 124 insertions(+), 17 deletions(-)

diff --git a/arch/arm/include/asm/arch-exynos/dwmmc.h b/arch/arm/include/asm/arch-exynos/dwmmc.h
index 8acdf9b..3b147b8 100644
--- a/arch/arm/include/asm/arch-exynos/dwmmc.h
+++ b/arch/arm/include/asm/arch-exynos/dwmmc.h
@@ -27,10 +27,7 @@
 #define DWMCI_SET_DRV_CLK(x)	((x) << 16)
 #define DWMCI_SET_DIV_RATIO(x)	((x) << 24)
 
-int exynos_dwmci_init(u32 regbase, int bus_width, int index);
-
-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);
-}
+#ifdef CONFIG_OF_CONTROL
+int exynos_dwmmc_init(const void *blob);
+#endif
+int exynos_dwmci_add_port(int index, u32 regbase, int bus_width, u32 clksel);
diff --git a/drivers/mmc/exynos_dw_mmc.c b/drivers/mmc/exynos_dw_mmc.c
index 72a31b7..4238dd9 100644
--- a/drivers/mmc/exynos_dw_mmc.c
+++ b/drivers/mmc/exynos_dw_mmc.c
@@ -19,39 +19,146 @@
  */
 
 #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>
 
-static char *EXYNOS_NAME = "EXYNOS DWMMC";
+#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
 
+/*
+ * 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)
+/*
+ * This function adds the mmc channel to be registered with mmc core.
+ * index -	mmc channel number.
+ * regbase -	register base address of mmc channel specified in 'index'.
+ * bus_width -	operating bus width of mmc channel specified in 'index'.
+ * clksel -	value to be written into CLKSEL register in case of FDT.
+ *		NULL in case od non-FDT.
+ */
+int exynos_dwmci_add_port(int index, u32 regbase, int bus_width, u32 clksel)
 {
 	struct dwmci_host *host = NULL;
+	unsigned int div;
+	unsigned long freq, sclk;
 	host = malloc(sizeof(struct dwmci_host));
 	if (!host) {
 		printf("dwmci_host malloc fail!\n");
 		return 1;
 	}
+	/* request mmc clock vlaue of 52MHz.  */
+	freq = 52000000;
+	sclk = get_mmc_clk(index);
+	div = DIV_ROUND_UP(sclk, freq);
+	/* set the clock divisor for mmc */
+	set_mmc_clk(index, div);
 
-	host->name = EXYNOS_NAME;
+	host->name = "EXYNOS DWMMC";
 	host->ioaddr = (void *)regbase;
 	host->buswidth = bus_width;
+
+	if (clksel) {
+		host->clksel_val = clksel;
+	} else {
+		if (0 == index)
+			host->clksel_val = DWMMC_MMC0_CLKSEL_VAL;
+		if (2 == index)
+			host->clksel_val = DWMMC_MMC2_CLKSEL_VAL;
+	}
+
 	host->clksel = exynos_dwmci_clksel;
 	host->dev_index = index;
+	host->mmc_clk = exynos_dwmci_get_clk;
+	/* Add the mmc channel to be registered with mmc core */
+	if (add_dwmci(host, DWMMC_MAX_FREQ, DWMMC_MIN_FREQ)) {
+		debug("dwmmc%d registration failed\n", index);
+		return -1;
+	}
+	return 0;
+}
+
+#ifdef CONFIG_OF_CONTROL
+int exynos_dwmmc_init(const void *blob)
+{
+	int index, bus_width;
+	int node_list[DWMMC_MAX_CH_NUM];
+	int err = 0, dev_id, flag, count, i;
+	u32 clksel_val, base, timing[3];
+
+	count = fdtdec_find_aliases_for_id(blob, "mmc",
+				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;
 
-	add_dwmci(host, 52000000, 400000);
+		/* 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;
+		}
+
+		clksel_val = (DWMCI_SET_SAMPLE_CLK(timing[0]) |
+				DWMCI_SET_DRV_CLK(timing[1]) |
+				DWMCI_SET_DIV_RATIO(timing[2]));
+		/* Initialise each mmc channel */
+		err = exynos_dwmci_add_port(index, base, bus_width, clksel_val);
+		if (err)
+			debug("dwmmc Channel-%d init failed\n", index);
+	}
 	return 0;
 }
-
+#endif
diff --git a/include/dwmmc.h b/include/dwmmc.h
index c8b1d40..e142f3e 100644
--- a/include/dwmmc.h
+++ b/include/dwmmc.h
@@ -123,6 +123,8 @@
 #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 +146,7 @@ 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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