[U-Boot] [PATCH] mx5: Add clock config interface
Stefano Babic
sbabic at denx.de
Mon Mar 19 16:27:07 CET 2012
On 16/03/2012 21:21, Fabio Estevam wrote:
> From: Jason Liu <jason.hui at linaro.org>
>
> mx5: Add clock config interface
Hi Fabio,
>
> 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 at linaro.org>
> Signed-off-by: Eric Miao <eric.miao at linaro.org>
> ---
My personal quote: this seems to introduce several changes as the clocks
are computed - my personal feeling is that this patch will go into the
-next branch.
>
> diff --git a/arch/arm/cpu/armv7/mx5/clock.c b/arch/arm/cpu/armv7/mx5/clock.c
> index e92f106..c7613f0 100644
> --- a/arch/arm/cpu/armv7/mx5/clock.c
> +++ b/arch/arm/cpu/armv7/mx5/clock.c
> @@ -24,6 +24,7 @@
> */
>
> #include <common.h>
> +#include <div64.h>
> #include <asm/io.h>
> #include <asm/errno.h>
> #include <asm/arch/imx-regs.h>
> @@ -48,6 +49,39 @@ 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
> +
> +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)
> @@ -212,20 +246,13 @@ static u32 get_periph_clk(void)
> /* NOTREACHED */
> }
>
> -/*
> - * Get the rate of ahb clock.
> - */
> static u32 get_ahb_clk(void)
> {
> - uint32_t freq, div, reg;
> + u32 cbcdr = __raw_readl(&mxc_ccm->cbcdr);
> + u32 pdf = (cbcdr & MXC_CCM_CBCDR_AHB_PODF_MASK) \
> + >> MXC_CCM_CBCDR_AHB_PODF_OFFSET;
>
> - freq = get_periph_clk();
> -
> - reg = __raw_readl(&mxc_ccm->cbcdr);
> - div = ((reg & MXC_CCM_CBCDR_AHB_PODF_MASK) >>
> - MXC_CCM_CBCDR_AHB_PODF_OFFSET) + 1;
> -
> - return freq / div;
> + return get_periph_clk() / (pdf + 1);
A good occasion to factorize with mx6 code. What about to move the
function into arch/arm/cpu/armv7/imx-common/ ?
> }
>
> /*
> @@ -306,7 +333,7 @@ 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)
Right, all internal functions should be static - thanks for fixing it.
>
> +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_nfc_clk(void)
> +{
> + u32 cbcdr = __raw_readl(&mxc_ccm->cbcdr);
> + u32 pdf = (cbcdr & MXC_CCM_CBCDR_NFC_PODF_MASK) \
> + >> MXC_CCM_CBCDR_NFC_PODF_OFFSET;
> +
> + return get_emi_slow_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.
> */
> @@ -376,10 +482,12 @@ unsigned int mxc_get_clock(enum mxc_clock clk)
> case MXC_UART_CLK:
> return get_uart_clk();
> case MXC_CSPI_CLK:
> - return imx_get_cspiclk();
> + return get_cspi_clk();
> case MXC_FEC_CLK:
> return decode_pll(mxc_plls[PLL1_CLOCK],
> CONFIG_SYS_MX5_HCLK);
> + case MXC_DDR_CLK:
> + return get_ddr_clk();
> default:
> break;
> }
> @@ -398,6 +506,424 @@ u32 imx_get_fecclk(void)
> }
>
> /*
> + * Clock config code start here
> + */
> +
> +/* precondition: m>0 and n>0. Let g=gcd(m,n). */
> +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.
> + *
> + * @param ref reference clock freq in Hz
> + * @param target targeted clock in Hz
> + * @param pll pll_param structure.
We have not doxygen in all u-boot code and this function remains an
exception. So you can drop all @statements. This should be fixed globally.
> + }
> + /* Now got pd and mfi already */
> + /*
> + mfn = (((n_target * pd) / 4 - n_ref * mfi) * mfd) / n_ref;
> + */
Dead code ?
> + t1 = n_target * pd;
> + do_div(t1, 4);
> + t1 -= n_ref * mfi;
> + t1 *= mfd;
> + do_div(t1, n_ref);
> + mfn = t1;
> +#ifdef CMD_CLOCK_DEBUG
> + printf("ref=%d, target=%d, pd=%d," "mfi=%d,mfn=%d, mfd=%d\n",
> + ref, n_target, (u32)pd, (u32)mfi, (u32)mfn, (u32)mfd);
What is CMD_CLOCK_DEBUG ? I think it is enough if you replace printf()
with debug()
> +
> +static u32 calc_per_cbcdr_val(u32 per_clk)
> +{
> + u32 cbcdr = __raw_readl(&mxc_ccm->cbcdr);
> + u32 tmp_clk = 0, div = 0, clk_sel = 0;
> +
> + cbcdr &= ~MXC_CCM_CBCDR_PERIPH_CLK_SEL;
> +
> + /* emi_slow_podf divider */
> + tmp_clk = get_emi_slow_clk();
> + clk_sel = cbcdr & MXC_CCM_CBCDR_EMI_CLK_SEL;
> + if (clk_sel) {
> + div = calc_div(tmp_clk, per_clk, 8);
> + cbcdr &= ~MXC_CCM_CBCDR_EMI_PODF_MASK;
> + cbcdr |= (div << MXC_CCM_CBCDR_EMI_PODF_OFFSET);
> + }
> +
> + /* axi_b_podf divider */
> + tmp_clk = get_axi_b_clk();
> + div = calc_div(tmp_clk, per_clk, 8);
> + cbcdr &= ~MXC_CCM_CBCDR_AXI_B_PODF_MASK;
> + cbcdr |= (div << MXC_CCM_CBCDR_AXI_B_PODF_OFFSET);
> +
> + /* axi_b_podf divider */
> + tmp_clk = get_axi_a_clk();
> + div = calc_div(tmp_clk, per_clk, 8);
> + cbcdr &= ~MXC_CCM_CBCDR_AXI_A_PODF_MASK;
> + cbcdr |= (div << MXC_CCM_CBCDR_AXI_A_PODF_OFFSET);
> +
> + /* ahb podf divider */
> + tmp_clk = AHB_CLK_ROOT;
> + div = calc_div(tmp_clk, per_clk, 8);
> + cbcdr &= ~MXC_CCM_CBCDR_AHB_PODF_MASK;
> + cbcdr |= (div << MXC_CCM_CBCDR_AHB_PODF_OFFSET);
> +
> + return cbcdr;
> +}
> +
> +#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 -1;
> + }
> +
> + 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 -1;
> + 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 -1;
> + }
> + } else {
> + u32 old_cbcmr = __raw_readl(&mxc_ccm->cbcmr);
> + u32 new_cbcdr = calc_per_cbcdr_val(freq);
> + u32 old_nfc = get_nfc_clk();
> +
> + /* Switch peripheral to PLL3 */
> + __raw_writel(0x00015154, &mxc_ccm->cbcmr);
> + __raw_writel(0x02888945, &mxc_ccm->cbcdr);
Can we set constants for these ?
> +
> + /* Make sure change is effective */
> + while (__raw_readl(&mxc_ccm->cdhipr) != 0)
> + ;
> +
> + /* Setup PLL2 */
> + ret = calc_pll_params(ref, freq, &pll_param);
> + if (ret != 0) {
> + printf("Error:Can't find pll parameters: %d\n",
> + ret);
> + return ret;
> + }
> + config_pll_clk(PLL2_CLOCK, &pll_param);
> +
> + /* Switch peripheral back */
> + __raw_writel(new_cbcdr, &mxc_ccm->cbcdr);
> + __raw_writel(old_cbcmr, &mxc_ccm->cbcmr);
> +
> + /* Make sure change is effective */
> + while (__raw_readl(&mxc_ccm->cdhipr) != 0)
> + ;
> + /* restore to old NFC clock */
> + config_nfc_clk(old_nfc);
> + }
> +
> + 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 -1;
> + }
> +
> + 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;
> +}
> +
> +/*!
Drop the "!"
Best regards,
Stefano Babic
--
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