mx5: Add clock config interface

mx5: Add clock config interface

Add clock config interface support, so that we
can configure CPU or DDR clock in the later init

Signed-off-by: Jason Liu <jason.hui@linaro.org>
Signed-off-by: Eric Miao <eric.miao@linaro.org>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>

1 files changed, 444 insertions, 4 deletions

diff --git a/arch/arm/cpu/armv7/mx5/clock.c b/arch/arm/cpu/armv7/mx5/clock.c
index 903e207..fc2406b 100644
--- a/arch/arm/cpu/armv7/mx5/clock.c
+++ b/arch/arm/cpu/armv7/mx5/clock.c
@@ -49,6 +49,42 @@ struct mxc_pll_reg *mxc_plls[PLL_CLOCKS] = {
 #endif
 };
 
+#define AHB_CLK_ROOT    133333333
+#define SZ_DEC_1M       1000000
+#define PLL_PD_MAX      16      /* Actual pd+1 */
+#define PLL_MFI_MAX     15
+#define PLL_MFI_MIN     5
+#define ARM_DIV_MAX     8
+#define IPG_DIV_MAX     4
+#define AHB_DIV_MAX     8
+#define EMI_DIV_MAX     8
+#define NFC_DIV_MAX     8
+
+#define MX5_CBCMR	0x00015154
+#define MX5_CBCDR	0x02888945
+
+struct fixed_pll_mfd {
+	u32 ref_clk_hz;
+	u32 mfd;
+};
+
+const struct fixed_pll_mfd fixed_mfd[] = {
+	{CONFIG_SYS_MX5_HCLK, 24 * 16},
+};
+
+struct pll_param {
+	u32 pd;
+	u32 mfi;
+	u32 mfn;
+	u32 mfd;
+};
+
+#define PLL_FREQ_MAX(ref_clk)  (4 * (ref_clk) * PLL_MFI_MAX)
+#define PLL_FREQ_MIN(ref_clk) \
+		((2 * (ref_clk) * (PLL_MFI_MIN - 1)) / PLL_PD_MAX)
+#define MAX_DDR_CLK     420000000
+#define NFC_CLK_MAX     34000000
+
 struct mxc_ccm_reg *mxc_ccm = (struct mxc_ccm_reg *)MXC_CCM_BASE;
 
 void set_usboh3_clk(void)
@@ -291,7 +327,7 @@ static u32 get_uart_clk(void)
 /*
  * This function returns the low power audio clock.
  */
-u32 get_lp_apm(void)
+static u32 get_lp_apm(void)
 {
 	u32 ret_val = 0;
 	u32 ccsr = __raw_readl(&mxc_ccm->ccsr);
@@ -307,7 +343,7 @@ u32 get_lp_apm(void)
 /*
  * get cspi clock rate.
  */
-u32 imx_get_cspiclk(void)
+static u32 imx_get_cspiclk(void)
 {
 	u32 ret_val = 0, pdf, pre_pdf, clk_sel;
 	u32 cscmr1 = __raw_readl(&mxc_ccm->cscmr1);
@@ -344,8 +380,77 @@ u32 imx_get_cspiclk(void)
 	return ret_val;
 }
 
+static u32 get_axi_a_clk(void)
+{
+	u32 cbcdr =  __raw_readl(&mxc_ccm->cbcdr);
+	u32 pdf = (cbcdr & MXC_CCM_CBCDR_AXI_A_PODF_MASK) \
+			>> MXC_CCM_CBCDR_AXI_A_PODF_OFFSET;
+
+	return  get_periph_clk() / (pdf + 1);
+}
+
+static u32 get_axi_b_clk(void)
+{
+	u32 cbcdr =  __raw_readl(&mxc_ccm->cbcdr);
+	u32 pdf = (cbcdr & MXC_CCM_CBCDR_AXI_B_PODF_MASK) \
+			>> MXC_CCM_CBCDR_AXI_B_PODF_OFFSET;
+
+	return  get_periph_clk() / (pdf + 1);
+}
+
+static u32 get_emi_slow_clk(void)
+{
+	u32 cbcdr = __raw_readl(&mxc_ccm->cbcdr);
+	u32 emi_clk_sel = cbcdr & MXC_CCM_CBCDR_EMI_CLK_SEL;
+	u32 pdf = (cbcdr & MXC_CCM_CBCDR_EMI_PODF_MASK) \
+			>> MXC_CCM_CBCDR_EMI_PODF_OFFSET;
+
+	if (emi_clk_sel)
+		return  get_ahb_clk() / (pdf + 1);
+
+	return  get_periph_clk() / (pdf + 1);
+}
+
+static u32 get_ddr_clk(void)
+{
+	u32 ret_val = 0;
+	u32 cbcmr = __raw_readl(&mxc_ccm->cbcmr);
+	u32 ddr_clk_sel = (cbcmr & MXC_CCM_CBCMR_DDR_CLK_SEL_MASK) \
+				>> MXC_CCM_CBCMR_DDR_CLK_SEL_OFFSET;
+#ifdef CONFIG_MX51
+	u32 cbcdr = __raw_readl(&mxc_ccm->cbcdr);
+	if (cbcdr & MXC_CCM_CBCDR_DDR_HIFREQ_SEL) {
+		u32 ddr_clk_podf = (cbcdr & MXC_CCM_CBCDR_DDR_PODF_MASK) >> \
+					MXC_CCM_CBCDR_DDR_PODF_OFFSET;
+
+		ret_val = decode_pll(mxc_plls[PLL1_CLOCK], CONFIG_SYS_MX5_HCLK);
+		ret_val /= ddr_clk_podf + 1;
+
+		return ret_val;
+	}
+#endif
+	switch (ddr_clk_sel) {
+	case 0:
+		ret_val = get_axi_a_clk();
+		break;
+	case 1:
+		ret_val = get_axi_b_clk();
+		break;
+	case 2:
+		ret_val = get_emi_slow_clk();
+		break;
+	case 3:
+		ret_val = get_ahb_clk();
+		break;
+	default:
+		break;
+	}
+
+	return ret_val;
+}
+
 /*
- * The API of get mxc clockes.
+ * The API of get mxc clocks.
  */
 unsigned int mxc_get_clock(enum mxc_clock clk)
 {
@@ -367,10 +472,12 @@ unsigned int mxc_get_clock(enum mxc_clock clk)
 				    CONFIG_SYS_MX5_HCLK);
 	case MXC_SATA_CLK:
 		return get_ahb_clk();
+	case MXC_DDR_CLK:
+		return get_ddr_clk();
 	default:
 		break;
 	}
-	return -1;
+	return -EINVAL;
 }
 
 u32 imx_get_uartclk(void)
@@ -384,6 +491,338 @@ u32 imx_get_fecclk(void)
 	return mxc_get_clock(MXC_IPG_CLK);
 }
 
+static int gcd(int m, int n)
+{
+	int t;
+	while (m > 0) {
+		if (n > m) {
+			t = m;
+			m = n;
+			n = t;
+		} /* swap */
+		m -= n;
+	}
+	return n;
+}
+
+/*
+ * This is to calculate various parameters based on reference clock and
+ * targeted clock based on the equation:
+ *      t_clk = 2*ref_freq*(mfi + mfn/(mfd+1))/(pd+1)
+ * This calculation is based on a fixed MFD value for simplicity.
+ */
+static int calc_pll_params(u32 ref, u32 target, struct pll_param *pll)
+{
+	u64 pd, mfi = 1, mfn, mfd, t1;
+	u32 n_target = target;
+	u32 n_ref = ref, i;
+
+	/*
+	 * Make sure targeted freq is in the valid range.
+	 * Otherwise the following calculation might be wrong!!!
+	 */
+	if (n_target < PLL_FREQ_MIN(ref) ||
+		n_target > PLL_FREQ_MAX(ref)) {
+		printf("Targeted peripheral clock should be"
+			"within [%d - %d]\n",
+			PLL_FREQ_MIN(ref) / SZ_DEC_1M,
+			PLL_FREQ_MAX(ref) / SZ_DEC_1M);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(fixed_mfd); i++) {
+		if (fixed_mfd[i].ref_clk_hz == ref) {
+			mfd = fixed_mfd[i].mfd;
+			break;
+		}
+	}
+
+	if (i == ARRAY_SIZE(fixed_mfd))
+		return -EINVAL;
+
+	/* Use n_target and n_ref to avoid overflow */
+	for (pd = 1; pd <= PLL_PD_MAX; pd++) {
+		t1 = n_target * pd;
+		do_div(t1, (4 * n_ref));
+		mfi = t1;
+		if (mfi > PLL_MFI_MAX)
+			return -EINVAL;
+		else if (mfi < 5)
+			continue;
+		break;
+	}
+	/*
+	 * Now got pd and mfi already
+	 *
+	 * mfn = (((n_target * pd) / 4 - n_ref * mfi) * mfd) / n_ref;
+	 */
+	t1 = n_target * pd;
+	do_div(t1, 4);
+	t1 -= n_ref * mfi;
+	t1 *= mfd;
+	do_div(t1, n_ref);
+	mfn = t1;
+	debug("ref=%d, target=%d, pd=%d," "mfi=%d,mfn=%d, mfd=%d\n",
+		ref, n_target, (u32)pd, (u32)mfi, (u32)mfn, (u32)mfd);
+	i = 1;
+	if (mfn != 0)
+		i = gcd(mfd, mfn);
+	pll->pd = (u32)pd;
+	pll->mfi = (u32)mfi;
+	do_div(mfn, i);
+	pll->mfn = (u32)mfn;
+	do_div(mfd, i);
+	pll->mfd = (u32)mfd;
+
+	return 0;
+}
+
+#define calc_div(tgt_clk, src_clk, limit) ({		\
+		u32 v = 0;				\
+		if (((src_clk) % (tgt_clk)) <= 100)	\
+			v = (src_clk) / (tgt_clk);	\
+		else					\
+			v = ((src_clk) / (tgt_clk)) + 1;\
+		if (v > limit)				\
+			v = limit;			\
+		(v - 1);				\
+	})
+
+#define CHANGE_PLL_SETTINGS(pll, pd, fi, fn, fd) \
+	{	\
+		__raw_writel(0x1232, &pll->ctrl);		\
+		__raw_writel(0x2, &pll->config);		\
+		__raw_writel((((pd) - 1) << 0) | ((fi) << 4),	\
+			&pll->op);				\
+		__raw_writel(fn, &(pll->mfn));			\
+		__raw_writel((fd) - 1, &pll->mfd);		\
+		__raw_writel((((pd) - 1) << 0) | ((fi) << 4),	\
+			&pll->hfs_op);				\
+		__raw_writel(fn, &pll->hfs_mfn);		\
+		__raw_writel((fd) - 1, &pll->hfs_mfd);		\
+		__raw_writel(0x1232, &pll->ctrl);		\
+		while (!__raw_readl(&pll->ctrl) & 0x1)		\
+			;\
+	}
+
+static int config_pll_clk(enum pll_clocks index, struct pll_param *pll_param)
+{
+	u32 ccsr = __raw_readl(&mxc_ccm->ccsr);
+	struct mxc_pll_reg *pll = mxc_plls[index];
+
+	switch (index) {
+	case PLL1_CLOCK:
+		/* Switch ARM to PLL2 clock */
+		__raw_writel(ccsr | 0x4, &mxc_ccm->ccsr);
+		CHANGE_PLL_SETTINGS(pll, pll_param->pd,
+					pll_param->mfi, pll_param->mfn,
+					pll_param->mfd);
+		/* Switch back */
+		__raw_writel(ccsr & ~0x4, &mxc_ccm->ccsr);
+		break;
+	case PLL2_CLOCK:
+		/* Switch to pll2 bypass clock */
+		__raw_writel(ccsr | 0x2, &mxc_ccm->ccsr);
+		CHANGE_PLL_SETTINGS(pll, pll_param->pd,
+					pll_param->mfi, pll_param->mfn,
+					pll_param->mfd);
+		/* Switch back */
+		__raw_writel(ccsr & ~0x2, &mxc_ccm->ccsr);
+		break;
+	case PLL3_CLOCK:
+		/* Switch to pll3 bypass clock */
+		__raw_writel(ccsr | 0x1, &mxc_ccm->ccsr);
+		CHANGE_PLL_SETTINGS(pll, pll_param->pd,
+					pll_param->mfi, pll_param->mfn,
+					pll_param->mfd);
+		/* Switch back */
+		__raw_writel(ccsr & ~0x1, &mxc_ccm->ccsr);
+		break;
+	case PLL4_CLOCK:
+		/* Switch to pll4 bypass clock */
+		__raw_writel(ccsr | 0x20, &mxc_ccm->ccsr);
+		CHANGE_PLL_SETTINGS(pll, pll_param->pd,
+					pll_param->mfi, pll_param->mfn,
+					pll_param->mfd);
+		/* Switch back */
+		__raw_writel(ccsr & ~0x20, &mxc_ccm->ccsr);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/* Config CPU clock */
+static int config_core_clk(u32 ref, u32 freq)
+{
+	int ret = 0;
+	struct pll_param pll_param;
+
+	memset(&pll_param, 0, sizeof(struct pll_param));
+
+	/* The case that periph uses PLL1 is not considered here */
+	ret = calc_pll_params(ref, freq, &pll_param);
+	if (ret != 0) {
+		printf("Error:Can't find pll parameters: %d\n", ret);
+		return ret;
+	}
+
+	return config_pll_clk(PLL1_CLOCK, &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 -EINVAL;
+	if (div == 0)
+		div++;
+	if (parent_rate / div > NFC_CLK_MAX)
+		div++;
+	reg = __raw_readl(&mxc_ccm->cbcdr);
+	reg &= ~MXC_CCM_CBCDR_NFC_PODF_MASK;
+	reg |= (div - 1) << MXC_CCM_CBCDR_NFC_PODF_OFFSET;
+	__raw_writel(reg, &mxc_ccm->cbcdr);
+	while (__raw_readl(&mxc_ccm->cdhipr) != 0)
+		;
+	return 0;
+}
+
+/* Config main_bus_clock for periphs */
+static int config_periph_clk(u32 ref, u32 freq)
+{
+	int ret = 0;
+	struct pll_param pll_param;
+
+	memset(&pll_param, 0, sizeof(struct pll_param));
+
+	if (__raw_readl(&mxc_ccm->cbcdr) & MXC_CCM_CBCDR_PERIPH_CLK_SEL) {
+		ret = calc_pll_params(ref, freq, &pll_param);
+		if (ret != 0) {
+			printf("Error:Can't find pll parameters: %d\n",
+				ret);
+			return ret;
+		}
+		switch ((__raw_readl(&mxc_ccm->cbcmr) & \
+			MXC_CCM_CBCMR_PERIPH_CLK_SEL_MASK) >> \
+			MXC_CCM_CBCMR_PERIPH_CLK_SEL_OFFSET) {
+		case 0:
+			return config_pll_clk(PLL1_CLOCK, &pll_param);
+			break;
+		case 1:
+			return config_pll_clk(PLL3_CLOCK, &pll_param);
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int config_ddr_clk(u32 emi_clk)
+{
+	u32 clk_src;
+	s32 shift = 0, clk_sel, div = 1;
+	u32 cbcmr = __raw_readl(&mxc_ccm->cbcmr);
+	u32 cbcdr = __raw_readl(&mxc_ccm->cbcdr);
+
+	if (emi_clk > MAX_DDR_CLK) {
+		printf("Warning:DDR clock should not exceed %d MHz\n",
+			MAX_DDR_CLK / SZ_DEC_1M);
+		emi_clk = MAX_DDR_CLK;
+	}
+
+	clk_src = get_periph_clk();
+	/* Find DDR clock input */
+	clk_sel = (cbcmr >> 10) & 0x3;
+	switch (clk_sel) {
+	case 0:
+		shift = 16;
+		break;
+	case 1:
+		shift = 19;
+		break;
+	case 2:
+		shift = 22;
+		break;
+	case 3:
+		shift = 10;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if ((clk_src % emi_clk) < 10000000)
+		div = clk_src / emi_clk;
+	else
+		div = (clk_src / emi_clk) + 1;
+	if (div > 8)
+		div = 8;
+
+	cbcdr = cbcdr & ~(0x7 << shift);
+	cbcdr |= ((div - 1) << shift);
+	__raw_writel(cbcdr, &mxc_ccm->cbcdr);
+	while (__raw_readl(&mxc_ccm->cdhipr) != 0)
+		;
+	__raw_writel(0x0, &mxc_ccm->ccdr);
+
+	return 0;
+}
+
+/*
+ * This function assumes the expected core clock has to be changed by
+ * modifying the PLL. This is NOT true always but for most of the times,
+ * it is. So it assumes the PLL output freq is the same as the expected
+ * core clock (presc=1) unless the core clock is less than PLL_FREQ_MIN.
+ * In the latter case, it will try to increase the presc value until
+ * (presc*core_clk) is greater than PLL_FREQ_MIN. It then makes call to
+ * calc_pll_params() and obtains the values of PD, MFI,MFN, MFD based
+ * on the targeted PLL and reference input clock to the PLL. Lastly,
+ * it sets the register based on these values along with the dividers.
+ * Note 1) There is no value checking for the passed-in divider values
+ *         so the caller has to make sure those values are sensible.
+ *      2) Also adjust the NFC divider such that the NFC clock doesn't
+ *         exceed NFC_CLK_MAX.
+ *      3) IPU HSP clock is independent of AHB clock. Even it can go up to
+ *         177MHz for higher voltage, this function fixes the max to 133MHz.
+ *      4) This function should not have allowed diag_printf() calls since
+ *         the serial driver has been stoped. But leave then here to allow
+ *         easy debugging by NOT calling the cyg_hal_plf_serial_stop().
+ */
+int mxc_set_clock(u32 ref, u32 freq, enum mxc_clock clk)
+{
+	freq *= SZ_DEC_1M;
+
+	switch (clk) {
+	case MXC_ARM_CLK:
+		if (config_core_clk(ref, freq))
+			return -EINVAL;
+		break;
+	case MXC_PERIPH_CLK:
+		if (config_periph_clk(ref, freq))
+			return -EINVAL;
+		break;
+	case MXC_DDR_CLK:
+		if (config_ddr_clk(freq))
+			return -EINVAL;
+		break;
+	case MXC_NFC_CLK:
+		if (config_nfc_clk(freq))
+			return -EINVAL;
+		break;
+	default:
+		printf("Warning:Unsupported or invalid clock type\n");
+	}
+
+	return 0;
+}
+
 #ifdef CONFIG_MX53
 /*
  * The clock for the external interface can be set to use internal clock
@@ -430,6 +869,7 @@ int do_mx5_showclocks(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	printf("AHB        %8d kHz\n", mxc_get_clock(MXC_AHB_CLK) / 1000);
 	printf("IPG        %8d kHz\n", mxc_get_clock(MXC_IPG_CLK) / 1000);
 	printf("IPG PERCLK %8d kHz\n", mxc_get_clock(MXC_IPG_PERCLK) / 1000);
+	printf("DDR        %8d kHz\n", mxc_get_clock(MXC_DDR_CLK) / 1000);
 
 	return 0;
 }