ENGR00132709 MX53: add "clk nfc" command support

Add "clk nfc" command support.
Limit NFC MAX clock as 34MHZ to be compatible with
some old NAND flashes.

Signed-off-by: Lily Zhang <r58066@freescale.com>

3 files changed, 39 insertions, 0 deletions

diff --git a/board/freescale/mx53_rd/mx53_rd.c b/board/freescale/mx53_rd/mx53_rd.c
index d88cb38..9c71514 100644
--- a/board/freescale/mx53_rd/mx53_rd.c
+++ b/board/freescale/mx53_rd/mx53_rd.c
@@ -1036,6 +1036,13 @@ void setup_nfc(void)
 		reg &= ~WEIM_GCR2_MUX16_BYP_GRANT_MASK;
 		__raw_writel(reg, WEIM_BASE_ADDR + i);
 	}
+
+	/* To be compatible with some old NAND flash,
+	 * limit NFC clocks as 34MHZ. The user can modify
+	 * it according to dedicate NAND flash
+	 */
+	clk_config(0, 34, MXC_NFC_CLK);
+
 #if defined(CONFIG_MX53_ARD)
 	mxc_request_iomux(MX53_PIN_NANDF_CS0,
 			IOMUX_CONFIG_ALT0);
diff --git a/common/cmd_clk.c b/common/cmd_clk.c
index 0d6123e..b4130f3 100644
--- a/common/cmd_clk.c
+++ b/common/cmd_clk.c
@@ -42,6 +42,8 @@ int do_clkops(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 			clk_info(PERIPH_CLK);
 		else if (strcmp(argv[1], "ddr") == 0)
 			clk_info(DDR_CLK);
+		else if (strcmp(argv[1], "nfc") == 0)
+			clk_info(MXC_NFC_CLK);
 		else
 			printf("Unsupported clock type!\n");
 		break;
@@ -53,6 +55,8 @@ int do_clkops(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 			clk_config(CONFIG_REF_CLK_FREQ, freq, PERIPH_CLK);
 		else if (strcmp(argv[1], "ddr") == 0)
 			clk_config(CONFIG_REF_CLK_FREQ, freq, DDR_CLK);
+		else if (strcmp(argv[1], "nfc") == 0)
+			clk_config(CONFIG_REF_CLK_FREQ, freq, MXC_NFC_CLK);
 		else
 			printf("Unsupported clock type!\n");
 		break;
@@ -75,6 +79,7 @@ U_BOOT_CMD(
 	"clk periph <peripheral clock in MHz> -"
 	"Setup/Display peripheral clock\n"
 	"clk ddr <DDR clock in MHz> - Setup/Display DDR clock\n"
+	"clk nfc <NFC clk in MHz> - Setup/Display NFC clock\n"
 	"Example:\n"
 	"clk - Show various clocks\n"
 	"clk core 665 - Set core clock to 665MHz\n"
diff --git a/cpu/arm_cortexa8/mx53/generic.c b/cpu/arm_cortexa8/mx53/generic.c
index 8904d9d..6ba61ee 100644
--- a/cpu/arm_cortexa8/mx53/generic.c
+++ b/cpu/arm_cortexa8/mx53/generic.c
@@ -789,6 +789,26 @@ static int config_core_clk(u32 ref, u32 freq)
 	return config_pll_clk(PLL1_CLK, &pll_param);
 }
 
+static int config_nfc_clk(u32 nfc_clk)
+{
+	u32 reg;
+	u32 parent_rate = __get_emi_slow_clk();
+	u32 div = parent_rate / nfc_clk;
+
+	if (nfc_clk <= 0)
+		return -1;
+	if (div == 0)
+		div++;
+	if (parent_rate / div > NFC_CLK_MAX)
+		div++;
+	reg = __REG(MXC_CCM_CBCDR);
+	reg &= ~MXC_CCM_CBCDR_NFC_PODF_MASK;
+	reg |= (div - 1) << MXC_CCM_CBCDR_NFC_PODF_OFFSET;
+	writel(reg, MXC_CCM_CBCDR);
+	while (readl(CCM_BASE_ADDR + CLKCTL_CDHIPR) != 0)
+		;
+	return 0;
+}
 static int config_periph_clk(u32 ref, u32 freq)
 {
 	int ret = 0;
@@ -820,6 +840,7 @@ static int config_periph_clk(u32 ref, u32 freq)
 	} else {
 		u32 old_cbcmr = readl(CCM_BASE_ADDR + CLKCTL_CBCMR);
 		u32 new_cbcdr = calc_per_cbcdr_val(pll, old_cbcmr);
+		u32 old_nfc = __get_nfc_clk();
 
 		/* Switch peripheral to PLL3 */
 		writel(0x00015154, CCM_BASE_ADDR + CLKCTL_CBCMR);
@@ -845,6 +866,8 @@ static int config_periph_clk(u32 ref, u32 freq)
 		/* Make sure change is effective */
 		while (readl(CCM_BASE_ADDR + CLKCTL_CDHIPR) != 0)
 			;
+		/* restore to old NFC clock */
+		config_nfc_clk(old_nfc);
 		puts("\n");
 	}
 
@@ -944,6 +967,10 @@ int clk_config(u32 ref, u32 freq, u32 clk_type)
 		if (config_ddr_clk(freq))
 			return -1;
 		break;
+	case MXC_NFC_CLK:
+		if (config_nfc_clk(freq))
+			return -1;
+		break;
 	default:
 		printf("Unsupported or invalid clock type! :(\n");
 	}