Re: [PATCH 4/7] clk: qcom: clk-alpha-pll: Add support for controlling Lucid PLLs

Bjorn Andersson
2020-01-24T18:24:05Z

On Thu 16 Jan 15:39 PST 2020, Venkata Narendra Kumar Gutta wrote:

> From: Taniya Das <tdas@codeaurora.org>
>
> Add programming sequence support for managing the Lucid PLLs.
>
> Signed-off-by: Taniya Das <tdas@codeaurora.org>
> Signed-off-by: Venkata Narendra Kumar Gutta <vnkgutta@codeaurora.org>

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

> ---
> drivers/clk/qcom/clk-alpha-pll.c | 190 +++++++++++++++++++++++++++++++++++++++
> drivers/clk/qcom/clk-alpha-pll.h | 12 +++
> 2 files changed, 202 insertions(+)
>
> diff --git a/drivers/clk/qcom/clk-alpha-pll.c b/drivers/clk/qcom/clk-alpha-pll.c
> index 1b073b2..4258ab0 100644
> --- a/drivers/clk/qcom/clk-alpha-pll.c
> +++ b/drivers/clk/qcom/clk-alpha-pll.c
> @@ -52,6 +52,7 @@
> #define PLL_CONFIG_CTL_U1(p) ((p)->offset + (p)->regs[PLL_OFF_CONFIG_CTL_U1])
> #define PLL_TEST_CTL(p) ((p)->offset + (p)->regs[PLL_OFF_TEST_CTL])
> #define PLL_TEST_CTL_U(p) ((p)->offset + (p)->regs[PLL_OFF_TEST_CTL_U])
> +#define PLL_TEST_CTL_U1(p) ((p)->offset + (p)->regs[PLL_OFF_TEST_CTL_U1])
> #define PLL_STATUS(p) ((p)->offset + (p)->regs[PLL_OFF_STATUS])
> #define PLL_OPMODE(p) ((p)->offset + (p)->regs[PLL_OFF_OPMODE])
> #define PLL_FRAC(p) ((p)->offset + (p)->regs[PLL_OFF_FRAC])
> @@ -116,6 +117,22 @@
> [PLL_OFF_ALPHA_VAL] = 0x40,
> [PLL_OFF_CAL_VAL] = 0x44,
> },
> + [CLK_ALPHA_PLL_TYPE_LUCID] = {
> + [PLL_OFF_L_VAL] = 0x04,
> + [PLL_OFF_CAL_L_VAL] = 0x08,
> + [PLL_OFF_USER_CTL] = 0x0c,
> + [PLL_OFF_USER_CTL_U] = 0x10,
> + [PLL_OFF_USER_CTL_U1] = 0x14,
> + [PLL_OFF_CONFIG_CTL] = 0x18,
> + [PLL_OFF_CONFIG_CTL_U] = 0x1c,
> + [PLL_OFF_CONFIG_CTL_U1] = 0x20,
> + [PLL_OFF_TEST_CTL] = 0x24,
> + [PLL_OFF_TEST_CTL_U] = 0x28,
> + [PLL_OFF_TEST_CTL_U1] = 0x2c,
> + [PLL_OFF_STATUS] = 0x30,
> + [PLL_OFF_OPMODE] = 0x38,
> + [PLL_OFF_ALPHA_VAL] = 0x40,
> + },
> };
> EXPORT_SYMBOL_GPL(clk_alpha_pll_regs);
>
> @@ -139,6 +156,10 @@
> #define PLL_OUT_MASK 0x7
> #define PLL_RATE_MARGIN 500
>
> +/* LUCID PLL specific settings and offsets */
> +#define LUCID_PLL_CAL_VAL 0x44
> +#define LUCID_PCAL_DONE BIT(26)
> +
> #define pll_alpha_width(p) \
> ((PLL_ALPHA_VAL_U(p) - PLL_ALPHA_VAL(p) == 4) ? \
> ALPHA_REG_BITWIDTH : ALPHA_REG_16BIT_WIDTH)
> @@ -1367,3 +1388,172 @@ static int clk_alpha_pll_postdiv_fabia_set_rate(struct clk_hw *hw,
> .set_rate = clk_alpha_pll_postdiv_fabia_set_rate,
> };
> EXPORT_SYMBOL_GPL(clk_alpha_pll_postdiv_fabia_ops);
> +
> +void clk_lucid_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
> + const struct alpha_pll_config *config)
> +{
> + if (config->l)
> + regmap_write(regmap, PLL_L_VAL(pll), config->l);
> +
> + regmap_write(regmap, PLL_CAL_L_VAL(pll), LUCID_PLL_CAL_VAL);
> +
> + if (config->alpha)
> + regmap_write(regmap, PLL_ALPHA_VAL(pll), config->alpha);
> +
> + if (config->config_ctl_val)
> + regmap_write(regmap, PLL_CONFIG_CTL(pll),
> + config->config_ctl_val);
> +
> + if (config->config_ctl_hi_val)
> + regmap_write(regmap, PLL_CONFIG_CTL_U(pll),
> + config->config_ctl_hi_val);
> +
> + if (config->config_ctl_hi1_val)
> + regmap_write(regmap, PLL_CONFIG_CTL_U1(pll),
> + config->config_ctl_hi1_val);
> +
> + if (config->user_ctl_val)
> + regmap_write(regmap, PLL_USER_CTL(pll),
> + config->user_ctl_val);
> +
> + if (config->user_ctl_hi_val)
> + regmap_write(regmap, PLL_USER_CTL_U(pll),
> + config->user_ctl_hi_val);
> +
> + if (config->user_ctl_hi1_val)
> + regmap_write(regmap, PLL_USER_CTL_U1(pll),
> + config->user_ctl_hi1_val);
> +
> + if (config->test_ctl_val)
> + regmap_write(regmap, PLL_TEST_CTL(pll),
> + config->test_ctl_val);
> +
> + if (config->test_ctl_hi_val)
> + regmap_write(regmap, PLL_TEST_CTL_U(pll),
> + config->test_ctl_hi_val);
> +
> + if (config->test_ctl_hi1_val)
> + regmap_write(regmap, PLL_TEST_CTL_U1(pll),
> + config->test_ctl_hi1_val);
> +
> + regmap_update_bits(regmap, PLL_MODE(pll), PLL_UPDATE_BYPASS,
> + PLL_UPDATE_BYPASS);
> +
> + /* Disable PLL output */
> + regmap_update_bits(regmap, PLL_MODE(pll), PLL_OUTCTRL, 0);
> +
> + /* Set operation mode to OFF */
> + regmap_write(regmap, PLL_OPMODE(pll), PLL_STANDBY);
> +
> + /* PLL should be in OFF mode before continuing */
> + wmb();
> +
> + /* Place the PLL in STANDBY mode */
> + regmap_update_bits(regmap, PLL_MODE(pll), PLL_RESET_N, PLL_RESET_N);
> +}
> +EXPORT_SYMBOL_GPL(clk_lucid_pll_configure);
> +
> +/*
> + * The Lucid PLL requires a power-on self-calibration which happens when the
> + * PLL comes out of reset. Calibrate in case it is not completed.
> + */
> +static int alpha_pll_lucid_prepare(struct clk_hw *hw)
> +{
> + struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
> + u32 regval;
> + int ret;
> +
> + /* Return early if calibration is not needed. */
> + regmap_read(pll->clkr.regmap, PLL_STATUS(pll), &regval);
> + if (regval & LUCID_PCAL_DONE)
> + return 0;
> +
> + ret = clk_trion_pll_enable(hw);
> + if (ret)
> + return ret;
> +
> + clk_trion_pll_disable(hw);
> +
> + return 0;
> +}
> +
> +static int alpha_pll_lucid_set_rate(struct clk_hw *hw, unsigned long rate,
> + unsigned long prate)
> +{
> + struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
> + unsigned long rrate;
> + u32 regval, l, alpha_width = pll_alpha_width(pll);
> + u64 a;
> + int ret;
> +
> + rrate = alpha_pll_round_rate(rate, prate, &l, &a, alpha_width);
> +
> + /*
> + * Due to a limited number of bits for fractional rate programming, the
> + * rounded up rate could be marginally higher than the requested rate.
> + */
> + if (rrate > (rate + PLL_RATE_MARGIN) || rrate < rate) {
> + pr_err("Call set rate on the PLL with rounded rates!\n");
> + return -EINVAL;
> + }
> +
> + regmap_write(pll->clkr.regmap, PLL_L_VAL(pll), l);
> + regmap_write(pll->clkr.regmap, PLL_ALPHA_VAL(pll), a);
> +
> + /* Latch the PLL input */
> + ret = regmap_update_bits(pll->clkr.regmap, PLL_MODE(pll),
> + PLL_UPDATE, PLL_UPDATE);
> + if (ret)
> + return ret;
> +
> + /* Wait for 2 reference cycles before checking the ACK bit. */
> + udelay(1);
> + regmap_read(pll->clkr.regmap, PLL_MODE(pll), &regval);
> + if (!(regval & ALPHA_PLL_ACK_LATCH)) {
> + WARN(1, "PLL latch failed. Output may be unstable!\n");
> + return -EINVAL;
> + }
> +
> + /* Return the latch input to 0 */
> + ret = regmap_update_bits(pll->clkr.regmap, PLL_MODE(pll),
> + PLL_UPDATE, 0);
> + if (ret)
> + return ret;
> +
> + if (clk_hw_is_enabled(hw)) {
> + ret = wait_for_pll_enable_lock(pll);
> + if (ret)
> + return ret;
> + }
> +
> + /* Wait for PLL output to stabilize */
> + udelay(100);
> + return 0;
> +}
> +
> +const struct clk_ops clk_alpha_pll_lucid_ops = {
> + .prepare = alpha_pll_lucid_prepare,
> + .enable = clk_trion_pll_enable,
> + .disable = clk_trion_pll_disable,
> + .is_enabled = clk_trion_pll_is_enabled,
> + .recalc_rate = clk_trion_pll_recalc_rate,
> + .round_rate = clk_alpha_pll_round_rate,
> + .set_rate = alpha_pll_lucid_set_rate,
> +};
> +EXPORT_SYMBOL_GPL(clk_alpha_pll_lucid_ops);
> +
> +const struct clk_ops clk_alpha_pll_fixed_lucid_ops = {
> + .enable = clk_trion_pll_enable,
> + .disable = clk_trion_pll_disable,
> + .is_enabled = clk_trion_pll_is_enabled,
> + .recalc_rate = clk_trion_pll_recalc_rate,
> + .round_rate = clk_alpha_pll_round_rate,
> +};
> +EXPORT_SYMBOL_GPL(clk_alpha_pll_fixed_lucid_ops);
> +
> +const struct clk_ops clk_alpha_pll_postdiv_lucid_ops = {
> + .recalc_rate = clk_alpha_pll_postdiv_fabia_recalc_rate,
> + .round_rate = clk_alpha_pll_postdiv_fabia_round_rate,
> + .set_rate = clk_alpha_pll_postdiv_fabia_set_rate,
> +};
> +EXPORT_SYMBOL_GPL(clk_alpha_pll_postdiv_lucid_ops);
> diff --git a/drivers/clk/qcom/clk-alpha-pll.h b/drivers/clk/qcom/clk-alpha-pll.h
> index fbc1f67..704674a 100644
> --- a/drivers/clk/qcom/clk-alpha-pll.h
> +++ b/drivers/clk/qcom/clk-alpha-pll.h
> @@ -14,6 +14,7 @@ enum {
> CLK_ALPHA_PLL_TYPE_BRAMMO,
> CLK_ALPHA_PLL_TYPE_FABIA,
> CLK_ALPHA_PLL_TYPE_TRION,
> + CLK_ALPHA_PLL_TYPE_LUCID,
> CLK_ALPHA_PLL_TYPE_MAX,
> };
>
> @@ -30,6 +31,7 @@ enum {
> PLL_OFF_CONFIG_CTL_U1,
> PLL_OFF_TEST_CTL,
> PLL_OFF_TEST_CTL_U,
> + PLL_OFF_TEST_CTL_U1,
> PLL_OFF_STATUS,
> PLL_OFF_OPMODE,
> PLL_OFF_FRAC,
> @@ -94,10 +96,13 @@ struct alpha_pll_config {
> u32 alpha_hi;
> u32 config_ctl_val;
> u32 config_ctl_hi_val;
> + u32 config_ctl_hi1_val;
> u32 user_ctl_val;
> u32 user_ctl_hi_val;
> + u32 user_ctl_hi1_val;
> u32 test_ctl_val;
> u32 test_ctl_hi_val;
> + u32 test_ctl_hi1_val;
> u32 main_output_mask;
> u32 aux_output_mask;
> u32 aux2_output_mask;
> @@ -123,10 +128,17 @@ struct alpha_pll_config {
> extern const struct clk_ops clk_alpha_pll_fixed_fabia_ops;
> extern const struct clk_ops clk_alpha_pll_postdiv_fabia_ops;
>
> +extern const struct clk_ops clk_alpha_pll_lucid_ops;
> +extern const struct clk_ops clk_alpha_pll_fixed_lucid_ops;
> +extern const struct clk_ops clk_alpha_pll_postdiv_lucid_ops;
> +
> void clk_alpha_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
> const struct alpha_pll_config *config);
> void clk_fabia_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
> const struct alpha_pll_config *config);
> +void clk_lucid_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
> + const struct alpha_pll_config *config);
> +
> extern const struct clk_ops clk_trion_fixed_pll_ops;
> extern const struct clk_ops clk_trion_pll_postdiv_ops;
>
> --
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> a Linux Foundation Collaborative Project