[PATCH v4 7/7] clk/qcom: fix rcg divider value
Caleb Connolly
caleb.connolly at linaro.org
Tue Nov 7 13:53:00 CET 2023
On 07/11/2023 12:41, Caleb Connolly 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 at linaro.org>
Forgot to pick up Sumit's R-b here.
> ---
> drivers/clk/qcom/clock-apq8016.c | 2 +-
> drivers/clk/qcom/clock-apq8096.c | 2 +-
> drivers/clk/qcom/clock-qcom.c | 64 +++++++++++++++++++++++++++++-----------
> drivers/clk/qcom/clock-qcom.h | 11 +++++++
> drivers/clk/qcom/clock-qcs404.c | 16 +++++-----
> drivers/clk/qcom/clock-sdm845.c | 26 ----------------
> 6 files changed, 67 insertions(+), 54 deletions(-)
>
> diff --git a/drivers/clk/qcom/clock-apq8016.c b/drivers/clk/qcom/clock-apq8016.c
> index 498e8ef6780d..c0ce570edc79 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 367c0f06ae20..cf1a347309a5 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..7c683e519226 100644
> --- a/drivers/clk/qcom/clock-qcom.c
> +++ b/drivers/clk/qcom/clock-qcom.c
> @@ -19,6 +19,8 @@
> #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 +70,42 @@ 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 +117,13 @@ 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 +140,7 @@ 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 +148,7 @@ 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 +156,22 @@ 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 f234ab5d6541..f5b352803927 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 6af1f38302d2..36ffee79d966 100644
> --- a/drivers/clk/qcom/clock-sdm845.c
> +++ b/drivers/clk/qcom/clock-sdm845.c
> @@ -27,16 +27,6 @@
> #define SE9_UART_APPS_N 0x18154
> #define SE9_UART_APPS_D 0x18158
>
> -#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),
> @@ -64,22 +54,6 @@ 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);
>
--
// Caleb (they/them)
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