[U-Boot] [PATCH 1/3] mx5: Add clock config interface

Fabio Estevam
2012-04-30T18:12:02Z

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>
---
Changes since v1:
- Rebased against Stefano's u-boot-imx plus the v2 version of
http://marc.info/?l=u-boot&m=133572323109396&w=2
- Fixed console output
- Use -EINVAL instead of -1

arch/arm/cpu/armv7/mx5/clock.c | 448 +++++++++++++++++++++++++++++-
arch/arm/include/asm/arch-mx5/clock.h | 5 +-
arch/arm/include/asm/arch-mx5/crm_regs.h | 6 +
3 files changed, 454 insertions(+), 5 deletions(-)

diff --git a/arch/arm/cpu/armv7/mx5/clock.c b/arch/arm/cpu/armv7/mx5/clock.c
index 903e207..30d86b4 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;
}
diff --git a/arch/arm/include/asm/arch-mx5/clock.h b/arch/arm/include/asm/arch-mx5/clock.h
index e822809..35ee815 100644
--- a/arch/arm/include/asm/arch-mx5/clock.h
+++ b/arch/arm/include/asm/arch-mx5/clock.h
@@ -33,6 +33,9 @@ enum mxc_clock {
MXC_CSPI_CLK,
MXC_FEC_CLK,
MXC_SATA_CLK,
+ MXC_DDR_CLK,
+ MXC_NFC_CLK,
+ MXC_PERIPH_CLK,
};

unsigned int imx_decode_pll(unsigned int pll, unsigned int f_ref);
@@ -40,7 +43,7 @@ unsigned int imx_decode_pll(unsigned int pll, unsigned int f_ref);
u32 imx_get_uartclk(void);
u32 imx_get_fecclk(void);
unsigned int mxc_get_clock(enum mxc_clock clk);
-
+int mxc_set_clock(u32 ref, u32 freq, u32 clk_type);
void set_usb_phy2_clk(void);
void enable_usb_phy2_clk(unsigned char enable);
void set_usboh3_clk(void);
diff --git a/arch/arm/include/asm/arch-mx5/crm_regs.h b/arch/arm/include/asm/arch-mx5/crm_regs.h
index bdeafbc..4e0fc1b 100644
--- a/arch/arm/include/asm/arch-mx5/crm_regs.h
+++ b/arch/arm/include/asm/arch-mx5/crm_regs.h
@@ -76,6 +76,9 @@ struct mxc_ccm_reg {
u32 CCGR4;
u32 CCGR5;
u32 CCGR6; /* 0x0080 */
+#ifdef CONFIG_MX53
+ u32 CCGR7; /* 0x0084 */
+#endif
u32 cmeor;
};

@@ -84,6 +87,9 @@ struct mxc_ccm_reg {
#define MXC_CCM_CACRR_ARM_PODF_MASK 0x7

/* Define the bits in register CBCDR */
+#define MXC_CCM_CBCDR_DDR_HIFREQ_SEL (0x1 << 30)
+#define MXC_CCM_CBCDR_DDR_PODF_MASK (0x7 << 27)
+#define MXC_CCM_CBCDR_DDR_PODF_OFFSET 27
#define MXC_CCM_CBCDR_EMI_CLK_SEL (0x1 << 26)
#define MXC_CCM_CBCDR_PERIPH_CLK_SEL (0x1 << 25)
#define MXC_CCM_CBCDR_EMI_PODF_OFFSET 22
--
1.7.1