Re: [PATCH v2 7/7] clk/qcom: fix rcg divider value

On Tue, 31 Oct 2023 at 03:54, Caleb Connolly caleb.connolly@linaro.org wrote:

The RCG divider field takes a value of (2*h - 1) where h is the divisor. This allows fractional dividers to be supported by calculating them at compile time using a macro.

However, the clk_rcg_set_rate_mnd() function was also performing the calculation. Clean this all up and consistently use the F() macro to calculate these at compile time and properly support fractional divisors.

Additionally, improve clk_bcr_update() to timeout with a warning rather than hanging the board, and make the freq_tbl struct and helpers common so that they can be reused by future platforms.

Signed-off-by: Caleb Connolly caleb.connolly@linaro.org

drivers/clk/qcom/clock-apq8016.c | 2 +- drivers/clk/qcom/clock-apq8096.c | 2 +- drivers/clk/qcom/clock-qcom.c | 66 +++++++++++++++++++++++++++++----------- drivers/clk/qcom/clock-qcom.h | 11 +++++++ drivers/clk/qcom/clock-qcs404.c | 16 +++++----- drivers/clk/qcom/clock-sdm845.c | 26 ---------------- 6 files changed, 69 insertions(+), 54 deletions(-)

Although changes look fine to me, I will find some cycles to give them a try on real hardware.

diff --git a/drivers/clk/qcom/clock-apq8016.c b/drivers/clk/qcom/clock-apq8016.c index 630619c83454..eb812934cbae 100644 --- a/drivers/clk/qcom/clock-apq8016.c +++ b/drivers/clk/qcom/clock-apq8016.c @@ -78,7 +78,7 @@ static struct vote_clk gcc_blsp1_ahb_clk = { /* SDHCI */ static int clk_init_sdc(struct msm_clk_priv *priv, int slot, uint rate) {

•   int div = 8; /* 100MHz default */
  

•   int div = 15; /* 100MHz default */
  
    if (rate == 200000000)
            div = 4;
  

diff --git a/drivers/clk/qcom/clock-apq8096.c b/drivers/clk/qcom/clock-apq8096.c index 095c1b431245..55f16c14e046 100644 --- a/drivers/clk/qcom/clock-apq8096.c +++ b/drivers/clk/qcom/clock-apq8096.c @@ -65,7 +65,7 @@ static struct vote_clk gcc_blsp2_ahb_clk = {

static int clk_init_sdc(struct msm_clk_priv *priv, uint rate) {

•   int div = 3;
  

•   int div = 5;
  
    clk_enable_cbc(priv->base + SDCC2_AHB_CBCR);
    clk_rcg_set_rate_mnd(priv->base, &sdc_regs, div, 0, 0,
  

diff --git a/drivers/clk/qcom/clock-qcom.c b/drivers/clk/qcom/clock-qcom.c index fc478554f982..58374d356942 100644 --- a/drivers/clk/qcom/clock-qcom.c +++ b/drivers/clk/qcom/clock-qcom.c @@ -12,6 +12,8 @@

• Based on Little Kernel driver, simplified

*/

+#define LOG_DEBUG

Only needed for debug purposes?

-Sumit

#include <common.h> #include <clk-uclass.h> #include <dm.h> @@ -19,6 +21,8 @@ #include <dm/lists.h> #include <errno.h> #include <asm/io.h> +#include <linux/bug.h> +#include <linux/delay.h> #include <linux/bitops.h> #include <reset-uclass.h>

@@ -68,30 +72,42 @@ void clk_enable_vote_clk(phys_addr_t base, const struct vote_clk *vclk) /* Update clock command via CMD_RCGR */ void clk_bcr_update(phys_addr_t apps_cmd_rcgr) {

•   u32 count;
    setbits_le32(apps_cmd_rcgr, APPS_CMD_RCGR_UPDATE);
  
    /* Wait for frequency to be updated. */
  

•   while (readl(apps_cmd_rcgr) & APPS_CMD_RCGR_UPDATE)
  

•           ;
  

•   for (count = 0; count < 50000; count++) {
  

•           if (!(readl(apps_cmd_rcgr) & APPS_CMD_RCGR_UPDATE))
  

•                   break;
  

•           udelay(1);
  

•   }
  

•   WARN(count == 50000, "WARNING: RCG @ %#llx [%#010x] stuck at off\n",
  

•        apps_cmd_rcgr, readl(apps_cmd_rcgr));
  

}

-#define CFG_MODE_DUAL_EDGE (0x2 << 12) /* Counter mode */ +#define CFG_SRC_DIV_MASK 0b11111 +#define CFG_SRC_SEL_SHIFT 8 +#define CFG_SRC_SEL_MASK (0x7 << CFG_SRC_SEL_SHIFT) +#define CFG_MODE_SHIFT 12 +#define CFG_MODE_MASK (0x3 << CFG_MODE_SHIFT) +#define CFG_MODE_DUAL_EDGE (0x2 << CFG_MODE_SHIFT) +#define CFG_HW_CLK_CTRL_MASK BIT(20)

-#define CFG_MASK 0x3FFF

-#define CFG_DIVIDER_MASK 0x1F

-/* root set rate for clocks with half integer and MND divider */ +/*

• • root set rate for clocks with half integer and MND divider
• • div should be pre-calculated ((div * 2) - 1)
• */

void clk_rcg_set_rate_mnd(phys_addr_t base, const struct bcr_regs *regs, int div, int m, int n, int source, u8 mnd_width) { u32 cfg; /* M value for MND divider. */ u32 m_val = m;

•   u32 n_minus_m = n - m;
    /* NOT(N-M) value for MND divider. */
  

•   u32 n_val = ~((n) - (m)) * !!(n);
  

•   u32 n_val = ~n_minus_m * !!(n);
    /* NOT 2D value for MND divider. */
  

•   u32 d_val = ~(n);
  

•   u32 d_val = ~(clamp_t(u32, n, m, n_minus_m));
    u32 mask = BIT(mnd_width) - 1;
  
    debug("m %#x n %#x d %#x div %#x mask %#x\n", m_val, n_val, d_val, div, mask);
  

@@ -103,15 +119,13 @@ void clk_rcg_set_rate_mnd(phys_addr_t base, const struct bcr_regs *regs,

    /* setup src select and divider */
    cfg  = readl(base + regs->cfg_rcgr);

•   cfg &= ~CFG_MASK;
  

•   cfg |= source & CFG_CLK_SRC_MASK; /* Select clock source */
  

•   cfg &= ~(CFG_SRC_SEL_MASK | CFG_MODE_MASK | CFG_HW_CLK_CTRL_MASK);
  

•   cfg |= source & CFG_SRC_SEL_MASK; /* Select clock source */
  
  

•   /* Set the divider; HW permits fraction dividers (+0.5), but
  

•      for simplicity, we will support integers only */
    if (div)
  

•           cfg |= (2 * div - 1) & CFG_DIVIDER_MASK;
  

•           cfg |= div & CFG_SRC_DIV_MASK;
  
  

•   if (n_val)
  

•   if (n && (n != m))
            cfg |= CFG_MODE_DUAL_EDGE;
  
    writel(cfg, base + regs->cfg_rcgr); /* Write new clock configuration */
  

@@ -128,7 +142,7 @@ void clk_rcg_set_rate(phys_addr_t base, const struct bcr_regs *regs, int div,

    /* setup src select and divider */
    cfg  = readl(base + regs->cfg_rcgr);

•   cfg &= ~CFG_MASK;
  

•   cfg &= ~(CFG_SRC_SEL_MASK | CFG_MODE_MASK | CFG_HW_CLK_CTRL_MASK);
    cfg |= source & CFG_CLK_SRC_MASK; /* Select clock source */
  
    /*
  

@@ -136,7 +150,7 @@ void clk_rcg_set_rate(phys_addr_t base, const struct bcr_regs *regs, int div, * for simplicity, we will support integers only */ if (div)

•           cfg |= (2 * div - 1) & CFG_DIVIDER_MASK;
  

•           cfg |= (2 * div - 1) & CFG_SRC_DIV_MASK;
  
    writel(cfg, base + regs->cfg_rcgr); /* Write new clock configuration */
  
  

@@ -144,6 +158,22 @@ void clk_rcg_set_rate(phys_addr_t base, const struct bcr_regs *regs, int div, clk_bcr_update(base + regs->cmd_rcgr); }

+const struct freq_tbl *qcom_find_freq(const struct freq_tbl *f, uint rate) +{

•   if (!f)
  

•           return NULL;
  

•   if (!f->freq)
  

•           return f;
  

•   for (; f->freq; f++)
  

•           if (rate <= f->freq)
  

•                   return f;
  

•   /* Default to our fastest rate */
  

•   return f - 1;
  

+}

static int msm_clk_probe(struct udevice *dev) { struct msm_clk_data *data = (struct msm_clk_data *)dev_get_driver_data(dev); diff --git a/drivers/clk/qcom/clock-qcom.h b/drivers/clk/qcom/clock-qcom.h index 24a32cb9666d..01088c19015a 100644 --- a/drivers/clk/qcom/clock-qcom.h +++ b/drivers/clk/qcom/clock-qcom.h @@ -32,6 +32,16 @@ struct bcr_regs { uintptr_t D; };

+struct freq_tbl {

•   uint freq;
  

•   uint src;
  

•   u8 pre_div;
  

•   u16 m;
  

•   u16 n;
  

+};

+#define F(f, s, h, m, n) { (f), (s), (2 * (h) - 1), (m), (n) }

struct gate_clk { uintptr_t reg; u32 en_val; @@ -71,6 +81,7 @@ void clk_enable_gpll0(phys_addr_t base, const struct pll_vote_clk *gpll0); void clk_bcr_update(phys_addr_t apps_cmd_rgcr); void clk_enable_cbc(phys_addr_t cbcr); void clk_enable_vote_clk(phys_addr_t base, const struct vote_clk *vclk); +const struct freq_tbl *qcom_find_freq(const struct freq_tbl *f, uint rate); void clk_rcg_set_rate_mnd(phys_addr_t base, const struct bcr_regs *regs, int div, int m, int n, int source, u8 mnd_width); void clk_rcg_set_rate(phys_addr_t base, const struct bcr_regs *regs, int div, diff --git a/drivers/clk/qcom/clock-qcs404.c b/drivers/clk/qcom/clock-qcs404.c index 921abf1f699b..429ff35e1d1a 100644 --- a/drivers/clk/qcom/clock-qcs404.c +++ b/drivers/clk/qcom/clock-qcs404.c @@ -203,7 +203,7 @@ static ulong qcs404_clk_set_rate(struct clk *clk, ulong rate) break; case GCC_SDCC1_APPS_CLK: /* SDCC1: 200MHz */

•           clk_rcg_set_rate_mnd(priv->base, &sdc_regs, 4, 0, 0,
  

•           clk_rcg_set_rate_mnd(priv->base, &sdc_regs, 7, 0, 0,
                                 CFG_CLK_SRC_GPLL0, 8);
            clk_enable_gpll0(priv->base, &gpll0_vote_clk);
            clk_enable_cbc(priv->base + SDCC_APPS_CBCR(1));
  

@@ -213,16 +213,16 @@ static ulong qcs404_clk_set_rate(struct clk *clk, ulong rate) break; case GCC_ETH_RGMII_CLK: if (rate == 250000000)

•                   clk_rcg_set_rate_mnd(priv->base, &emac_regs, 2, 0, 0,
  

•                   clk_rcg_set_rate_mnd(priv->base, &emac_regs, 3, 0, 0,
                                         CFG_CLK_SRC_GPLL1, 8);
            else if (rate == 125000000)
  

•                   clk_rcg_set_rate_mnd(priv->base, &emac_regs, 4, 0, 0,
  

•                   clk_rcg_set_rate_mnd(priv->base, &emac_regs, 7, 0, 0,
                                         CFG_CLK_SRC_GPLL1, 8);
            else if (rate == 50000000)
  

•                   clk_rcg_set_rate_mnd(priv->base, &emac_regs, 10, 0, 0,
  

•                   clk_rcg_set_rate_mnd(priv->base, &emac_regs, 19, 0, 0,
                                         CFG_CLK_SRC_GPLL1, 8);
            else if (rate == 5000000)
  

•                   clk_rcg_set_rate_mnd(priv->base, &emac_regs, 2, 1, 50,
  

•                   clk_rcg_set_rate_mnd(priv->base, &emac_regs, 3, 1, 50,
                                         CFG_CLK_SRC_GPLL1, 8);
            break;
    default:
  

@@ -239,7 +239,7 @@ static int qcs404_clk_enable(struct clk *clk) switch (clk->id) { case GCC_USB30_MASTER_CLK: clk_enable_cbc(priv->base + USB30_MASTER_CBCR);

•           clk_rcg_set_rate_mnd(priv->base, &usb30_master_regs, 4, 0, 0,
  

•           clk_rcg_set_rate_mnd(priv->base, &usb30_master_regs, 7, 0, 0,
                                 CFG_CLK_SRC_GPLL0, 8);
            break;
    case GCC_SYS_NOC_USB3_CLK:
  

@@ -261,14 +261,14 @@ static int qcs404_clk_enable(struct clk *clk) /* SPEED_1000: freq -> 250MHz */ clk_enable_cbc(priv->base + ETH_PTP_CBCR); clk_enable_gpll0(priv->base, &gpll1_vote_clk);

•           clk_rcg_set_rate_mnd(priv->base, &emac_ptp_regs, 2, 0, 0,
  

•           clk_rcg_set_rate_mnd(priv->base, &emac_ptp_regs, 3, 0, 0,
                                 CFG_CLK_SRC_GPLL1, 8);
            break;
    case GCC_ETH_RGMII_CLK:
            /* SPEED_1000: freq -> 250MHz */
            clk_enable_cbc(priv->base + ETH_RGMII_CBCR);
            clk_enable_gpll0(priv->base, &gpll1_vote_clk);
  

•           clk_rcg_set_rate_mnd(priv->base, &emac_regs, 2, 0, 0,
  

•           clk_rcg_set_rate_mnd(priv->base, &emac_regs, 3, 0, 0,
                                 CFG_CLK_SRC_GPLL1, 8);
            break;
    case GCC_ETH_SLAVE_AHB_CLK:
  

diff --git a/drivers/clk/qcom/clock-sdm845.c b/drivers/clk/qcom/clock-sdm845.c index 9e78da482c65..07e3605cdbaf 100644 --- a/drivers/clk/qcom/clock-sdm845.c +++ b/drivers/clk/qcom/clock-sdm845.c @@ -30,16 +30,6 @@ #define USB30_SEC_GDSCR 0x10004 #define USB30_PRIM_GDSCR 0xf004

-#define F(f, s, h, m, n) { (f), (s), (2 * (h) - 1), (m), (n) }

-struct freq_tbl {

•   uint freq;
  

•   uint src;
  

•   u8 pre_div;
  

•   u16 m;
  

•   u16 n;
  

-};

static const struct freq_tbl ftbl_gcc_qupv3_wrap0_s0_clk_src[] = { F(7372800, CFG_CLK_SRC_GPLL0_EVEN, 1, 384, 15625), F(14745600, CFG_CLK_SRC_GPLL0_EVEN, 1, 768, 15625), @@ -67,22 +57,6 @@ static const struct bcr_regs uart2_regs = { .D = SE9_UART_APPS_D, };

-const struct freq_tbl *qcom_find_freq(const struct freq_tbl *f, uint rate) -{

•   if (!f)
  

•           return NULL;
  

•   if (!f->freq)
  

•           return f;
  

•   for (; f->freq; f++)
  

•           if (rate <= f->freq)
  

•                   return f;
  

•   /* Default to our fastest rate */
  

•   return f - 1;
  

-}

static ulong sdm845_clk_set_rate(struct clk *clk, ulong rate) { struct msm_clk_priv *priv = dev_get_priv(clk->dev);

-- 2.42.0