mx51: add resources for SD/MMC on i.MX51

the attached patch allows SD to work on i.MX51 with Wolfram's drivers
Tested on i.MX51.

Based on original patch from: Richard Zhu <r65037@freescale.com>
Signed-off-by: Eric Bénard <eric@eukrea.com>

2 files changed, 113 insertions, 0 deletions

diff --git a/arch/arm/mach-mx5/clock-mx51.c b/arch/arm/mach-mx5/clock-mx51.c
index 9a39492c5b23..f2aae92cf0e2 100644
--- a/arch/arm/mach-mx5/clock-mx51.c
+++ b/arch/arm/mach-mx5/clock-mx51.c
@@ -41,6 +41,36 @@ static struct clk usboh3_clk;
 
 #define MAX_DPLL_WAIT_TRIES     1000 /* 1000 * udelay(1) = 1ms */
 
+/* calculate best pre and post dividers to get the required divider */
+static void __calc_pre_post_dividers(u32 div, u32 *pre, u32 *post,
+        u32 max_pre, u32 max_post)
+{
+        if (div >= max_pre * max_post) {
+                *pre = max_pre;
+                *post = max_post;
+        } else if (div >= max_pre) {
+                u32 min_pre, temp_pre, old_err, err;
+                min_pre = DIV_ROUND_UP(div, max_post);
+                old_err = max_pre;
+                for (temp_pre = max_pre; temp_pre >= min_pre; temp_pre--) {
+                        err = div % temp_pre;
+                        if (err == 0) {
+                                *pre = temp_pre;
+                                break;
+                        }
+                        err = temp_pre - err;
+                        if (err < old_err) {
+                                old_err = err;
+                                *pre = temp_pre;
+                        }
+                }
+                *post = DIV_ROUND_UP(div, *pre);
+        } else {
+                *pre = div;
+                *post = 1;
+        }
+}
+
 static void _clk_ccgr_setclk(struct clk *clk, unsigned mode)
 {
         u32 reg = __raw_readl(clk->enable_reg);
@@ -787,6 +817,20 @@ static struct clk emi_slow_clk = {
                 .secondary      = s,                    \
         }
 
+#define DEFINE_CLOCK_MAX(name, i, er, es, pfx, p, s)    \
+        static struct clk name = {                      \
+                .id             = i,                    \
+                .enable_reg     = er,                   \
+                .enable_shift   = es,                   \
+                .get_rate       = pfx##_get_rate,       \
+                .set_rate       = pfx##_set_rate,       \
+                .set_parent     = pfx##_set_parent,     \
+                .enable         = _clk_max_enable,      \
+                .disable        = _clk_max_disable,     \
+                .parent         = p,                    \
+                .secondary      = s,                    \
+        }
+
 #define CLK_GET_RATE(name, nr, bitsname)                                \
 static unsigned long clk_##name##_get_rate(struct clk *clk)             \
 {                                                                       \
@@ -817,6 +861,37 @@ static int clk_##name##_set_parent(struct clk *clk, struct clk *parent)	\
         return 0;                                                       \
 }
 
+#define CLK_SET_RATE(name, nr, bitsname)                                \
+static int clk_##name##_set_rate(struct clk *clk, unsigned long rate)   \
+{                                                                       \
+        u32 reg, div, parent_rate;                                      \
+        u32 pre = 0, post = 0;                                          \
+                                                                        \
+        parent_rate = clk_get_rate(clk->parent);                        \
+        div = parent_rate / rate;                                       \
+                                                                        \
+        if ((parent_rate / div) != rate)                                \
+                return -EINVAL;                                         \
+                                                                        \
+        __calc_pre_post_dividers(div, &pre, &post,                      \
+                (MXC_CCM_CSCDR##nr##_##bitsname##_CLK_PRED_MASK >>      \
+                MXC_CCM_CSCDR##nr##_##bitsname##_CLK_PRED_OFFSET) + 1,  \
+                (MXC_CCM_CSCDR##nr##_##bitsname##_CLK_PODF_MASK >>      \
+                MXC_CCM_CSCDR##nr##_##bitsname##_CLK_PODF_OFFSET) + 1);\
+                                                                        \
+        /* Set sdhc1 clock divider */                                   \
+        reg = __raw_readl(MXC_CCM_CSCDR##nr) &                          \
+                ~(MXC_CCM_CSCDR##nr##_##bitsname##_CLK_PRED_MASK        \
+                | MXC_CCM_CSCDR##nr##_##bitsname##_CLK_PODF_MASK);      \
+        reg |= (post - 1) <<                                            \
+                MXC_CCM_CSCDR##nr##_##bitsname##_CLK_PODF_OFFSET;       \
+        reg |= (pre - 1) <<                                             \
+                MXC_CCM_CSCDR##nr##_##bitsname##_CLK_PRED_OFFSET;       \
+        __raw_writel(reg, MXC_CCM_CSCDR##nr);                           \
+                                                                        \
+        return 0;                                                       \
+}
+
 /* UART */
 CLK_GET_RATE(uart, 1, UART)
 CLK_SET_PARENT(uart, 1, UART)
@@ -847,6 +922,15 @@ static struct clk ecspi_main_clk = {
         .set_parent = clk_ecspi_set_parent,
 };
 
+/* eSDHC */
+CLK_GET_RATE(esdhc1, 1, ESDHC1_MSHC1)
+CLK_SET_PARENT(esdhc1, 1, ESDHC1_MSHC1)
+CLK_SET_RATE(esdhc1, 1, ESDHC1_MSHC1)
+
+CLK_GET_RATE(esdhc2, 1, ESDHC2_MSHC2)
+CLK_SET_PARENT(esdhc2, 1, ESDHC2_MSHC2)
+CLK_SET_RATE(esdhc2, 1, ESDHC2_MSHC2)
+
 #define DEFINE_CLOCK_FULL(name, i, er, es, gr, sr, e, d, p, s)          \
         static struct clk name = {                                      \
                 .id             = i,                                    \
@@ -935,6 +1019,16 @@ DEFINE_CLOCK(cspi_clk, 0, MXC_CCM_CCGR4, MXC_CCM_CCGRx_CG13_OFFSET,
 DEFINE_CLOCK(sdma_clk, 1, MXC_CCM_CCGR4, MXC_CCM_CCGRx_CG15_OFFSET,
                 NULL, NULL, &ahb_clk, NULL);
 
+/* eSDHC */
+DEFINE_CLOCK_FULL(esdhc1_ipg_clk, 0, MXC_CCM_CCGR3, MXC_CCM_CCGRx_CG0_OFFSET,
+        NULL,  NULL, _clk_max_enable, _clk_max_disable, &ipg_clk, NULL);
+DEFINE_CLOCK_MAX(esdhc1_clk, 0, MXC_CCM_CCGR3, MXC_CCM_CCGRx_CG1_OFFSET,
+        clk_esdhc1, &pll2_sw_clk, &esdhc1_ipg_clk);
+DEFINE_CLOCK_FULL(esdhc2_ipg_clk, 1, MXC_CCM_CCGR3, MXC_CCM_CCGRx_CG2_OFFSET,
+        NULL,  NULL, _clk_max_enable, _clk_max_disable, &ipg_clk, NULL);
+DEFINE_CLOCK_MAX(esdhc2_clk, 1, MXC_CCM_CCGR3, MXC_CCM_CCGRx_CG3_OFFSET,
+        clk_esdhc2, &pll2_sw_clk, &esdhc2_ipg_clk);
+
 #define _REGISTER_CLOCK(d, n, c) \
        { \
                 .dev_id = d, \
@@ -968,6 +1062,8 @@ static struct clk_lookup lookups[] = {
         _REGISTER_CLOCK("imx51-ecspi.0", NULL, ecspi1_clk)
         _REGISTER_CLOCK("imx51-ecspi.1", NULL, ecspi2_clk)
         _REGISTER_CLOCK("imx51-cspi.0", NULL, cspi_clk)
+        _REGISTER_CLOCK("sdhci-esdhc-imx.0", NULL, esdhc1_clk)
+        _REGISTER_CLOCK("sdhci-esdhc-imx.1", NULL, esdhc2_clk)
 };
 
 static void clk_tree_init(void)
@@ -1011,6 +1107,14 @@ int __init mx51_clocks_init(unsigned long ckil, unsigned long osc,
         /* set the usboh3_clk parent to pll2_sw_clk */
         clk_set_parent(&usboh3_clk, &pll2_sw_clk);
 
+        /* Set SDHC parents to be PLL2 */
+        clk_set_parent(&esdhc1_clk, &pll2_sw_clk);
+        clk_set_parent(&esdhc2_clk, &pll2_sw_clk);
+
+        /* set SDHC root clock as 166.25MHZ*/
+        clk_set_rate(&esdhc1_clk, 166250000);
+        clk_set_rate(&esdhc2_clk, 166250000);
+
         /* System timer */
         mxc_timer_init(&gpt_clk, MX51_IO_ADDRESS(MX51_GPT1_BASE_ADDR),
                 MX51_MXC_INT_GPT);
diff --git a/arch/arm/mach-mx5/devices-imx51.h b/arch/arm/mach-mx5/devices-imx51.h
index c233379256b8..547432d8420f 100644
--- a/arch/arm/mach-mx5/devices-imx51.h
+++ b/arch/arm/mach-mx5/devices-imx51.h
@@ -36,3 +36,12 @@ extern const struct imx_spi_imx_data imx51_cspi_data __initconst;
 extern const struct imx_spi_imx_data imx51_ecspi_data[] __initconst;
 #define imx51_add_ecspi(id, pdata)      \
         imx_add_spi_imx(&imx51_ecspi_data[id], pdata)
+
+#define imx51_add_esdhc0(pdata) \
+        imx_add_esdhc(0, MX51_MMC_SDHC1_BASE_ADDR, SZ_16K, MX51_MXC_INT_MMC_SDHC1, pdata)
+#define imx51_add_esdhc1(pdata) \
+        imx_add_esdhc(1, MX51_MMC_SDHC2_BASE_ADDR, SZ_16K, MX51_MXC_INT_MMC_SDHC2, pdata)
+#define imx51_add_esdhc2(pdata) \
+        imx_add_esdhc(2, MX51_MMC_SDHC3_BASE_ADDR, SZ_16K, MX51_MXC_INT_MMC_SDHC3, pdata)
+#define imx51_add_esdhc3(pdata) \
+        imx_add_esdhc(3, MX51_MMC_SDHC4_BASE_ADDR, SZ_16K, MX51_MXC_INT_MMC_SDHC4, pdata)