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SubjectRe: [PATCH V4] clk: qcom: clk-alpha-pll: Add support for Stromer PLLs
From
Hi Stephen,

Thanks for taking time to review the patch.


On 1/13/2023 5:23 AM, Stephen Boyd wrote:
> Quoting Kathiravan T (2022-12-27 05:25:07)
>> diff --git a/drivers/clk/qcom/clk-alpha-pll.c b/drivers/clk/qcom/clk-alpha-pll.c
>> index f9e4cfd7261c..29866100df08 100644
>> --- a/drivers/clk/qcom/clk-alpha-pll.c
>> +++ b/drivers/clk/qcom/clk-alpha-pll.c
>> @@ -204,9 +204,24 @@ const u8 clk_alpha_pll_regs[][PLL_OFF_MAX_REGS] = {
>> [PLL_OFF_CONFIG_CTL] = 0x1C,
>> [PLL_OFF_STATUS] = 0x20,
>> },
>> + [CLK_ALPHA_PLL_TYPE_STROMER] = {
>> + [PLL_OFF_L_VAL] = 0x08,
>> + [PLL_OFF_ALPHA_VAL] = 0x10,
>> + [PLL_OFF_ALPHA_VAL_U] = 0x14,
>> + [PLL_OFF_USER_CTL] = 0x18,
>> + [PLL_OFF_USER_CTL_U] = 0x1c,
>> + [PLL_OFF_CONFIG_CTL] = 0x20,
>> + [PLL_OFF_CONFIG_CTL_U] = 0xff,
>> + [PLL_OFF_TEST_CTL] = 0x30,
>> + [PLL_OFF_TEST_CTL_U] = 0x34,
>> + [PLL_OFF_STATUS] = 0x28,
>> + },
>> };
>> EXPORT_SYMBOL_GPL(clk_alpha_pll_regs);
>>
>> +static unsigned long
>> +alpha_pll_round_rate(unsigned long rate, unsigned long prate, u32 *l, u64 *a,
> Is this necessary?


Not really, will re-arrange the functions and drop this.


>
>> + u32 alpha_width);
>> /*
>> * Even though 40 bits are present, use only 32 for ease of calculation.
>> */
>> @@ -215,6 +230,8 @@ EXPORT_SYMBOL_GPL(clk_alpha_pll_regs);
>> #define ALPHA_BITWIDTH 32U
>> #define ALPHA_SHIFT(w) min(w, ALPHA_BITWIDTH)
>>
>> +#define ALPHA_PLL_STATUS_REG_SHIFT 8
>> +
>> #define PLL_HUAYRA_M_WIDTH 8
>> #define PLL_HUAYRA_M_SHIFT 8
>> #define PLL_HUAYRA_M_MASK 0xff
>> @@ -325,7 +342,7 @@ static void clk_alpha_pll_write_config(struct regmap *regmap, unsigned int reg,
>> void clk_alpha_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
>> const struct alpha_pll_config *config)
>> {
>> - u32 val, mask;
>> + u32 val, val_u, mask, mask_u;
>>
>> regmap_write(regmap, PLL_L_VAL(pll), config->l);
>> regmap_write(regmap, PLL_ALPHA_VAL(pll), config->alpha);
>> @@ -355,14 +372,85 @@ void clk_alpha_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
>> mask |= config->pre_div_mask;
>> mask |= config->post_div_mask;
>> mask |= config->vco_mask;
>> + mask |= config->alpha_en_mask;
>> + mask |= config->alpha_mode_mask;
>>
>> regmap_update_bits(regmap, PLL_USER_CTL(pll), mask, val);
>>
>> + /* Stromer APSS PLL does not enable LOCK_DET by default, so enable it */
> Instead of adding these things to clk_alpha_pll_configure() can you
> introduce another api like clk_stromer_pll_configure() that sets these
> values unconditionally? That way we don't have to think or worry about
> the other alpha PLLs (of which there are many).


Sure, will introduce the new API.

>
>> + val_u = config->status_reg_val << ALPHA_PLL_STATUS_REG_SHIFT;
>> + val_u |= config->lock_det;
>> +
>> + mask_u = config->status_reg_mask;
>> + mask_u |= config->lock_det;
>> +
>> + if (val_u)
>> + regmap_update_bits(regmap, PLL_USER_CTL_U(pll), mask_u, val_u);
>> +
>> + 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 (pll->flags & SUPPORTS_FSM_MODE)
>> qcom_pll_set_fsm_mode(regmap, PLL_MODE(pll), 6, 0);
>> }
>> EXPORT_SYMBOL_GPL(clk_alpha_pll_configure);
>>
>> +static int clk_alpha_pll_stromer_determine_rate(struct clk_hw *hw,
>> + struct clk_rate_request *req)
>> +{
>> + u32 l;
>> + u64 a;
>> +
>> + req->rate = alpha_pll_round_rate(req->rate, req->best_parent_rate,
>> + &l, &a, ALPHA_REG_BITWIDTH);
>> +
>> + return 0;
>> +}
>> +
>> +static int clk_alpha_pll_stromer_set_rate(struct clk_hw *hw, unsigned long rate,
>> + unsigned long prate)
>> +{
>> + struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
>> + u32 l;
>> + int ret;
>> + u64 a;
>> +
>> + rate = alpha_pll_round_rate(rate, prate, &l, &a, ALPHA_REG_BITWIDTH);
>> +
>> + regmap_write(pll->clkr.regmap, PLL_L_VAL(pll), l);
>> + regmap_write(pll->clkr.regmap, PLL_ALPHA_VAL(pll), a);
>> + regmap_write(pll->clkr.regmap, PLL_ALPHA_VAL_U(pll),
>> + a >> ALPHA_BITWIDTH);
>> +
>> + regmap_update_bits(pll->clkr.regmap, PLL_USER_CTL(pll),
>> + PLL_ALPHA_EN, PLL_ALPHA_EN);
>> +
>> + if (!clk_hw_is_enabled(hw))
>> + return 0;
>> +
>> + /*
>> + * Stromer PLL supports Dynamic programming.
>> + * It allows the PLL frequency to be changed on-the-fly without first
>> + * execution of a shutdown procedure followed by a bring up procedure.
>> + */
>> +
> Drop newline above please.


Ack.


>
>> + regmap_update_bits(pll->clkr.regmap, PLL_MODE(pll), PLL_UPDATE,
>> + PLL_UPDATE);
>> +
>> + ret = wait_for_pll_update(pll);
>> + if (ret)
>> + return ret;
>> +
>> + ret = wait_for_pll_enable_lock(pll);
>> + if (ret)
>> + return ret;
>> +
>> + return 0;
> Just use
>
> return wait_for_pll_enable_lock(pll);


Ack.


>
>> +}
>> +
>> static int clk_alpha_pll_hwfsm_enable(struct clk_hw *hw)
>> {
>> int ret;
>> @@ -1013,6 +1101,16 @@ const struct clk_ops clk_alpha_pll_hwfsm_ops = {
>> };
>> EXPORT_SYMBOL_GPL(clk_alpha_pll_hwfsm_ops);
>>
>> +const struct clk_ops clk_alpha_pll_stromer_ops = {
>> + .enable = clk_alpha_pll_enable,
>> + .disable = clk_alpha_pll_disable,
>> + .is_enabled = clk_alpha_pll_is_enabled,
>> + .recalc_rate = clk_alpha_pll_recalc_rate,
>> + .determine_rate = clk_alpha_pll_stromer_determine_rate,
>> + .set_rate = clk_alpha_pll_stromer_set_rate,
>> +};
>> +EXPORT_SYMBOL_GPL(clk_alpha_pll_stromer_ops);
>> +
>> const struct clk_ops clk_alpha_pll_fixed_trion_ops = {
>> .enable = clk_trion_pll_enable,
>> .disable = clk_trion_pll_disable,
>> diff --git a/drivers/clk/qcom/clk-alpha-pll.h b/drivers/clk/qcom/clk-alpha-pll.h
>> index 2bdae362c827..1d122919e275 100644
>> --- a/drivers/clk/qcom/clk-alpha-pll.h
>> +++ b/drivers/clk/qcom/clk-alpha-pll.h
>> @@ -1,5 +1,5 @@
>> /* SPDX-License-Identifier: GPL-2.0 */
>> -/* Copyright (c) 2015, 2018, The Linux Foundation. All rights reserved. */
>> +/* Copyright (c) 2015, 2018, 2021 The Linux Foundation. All rights reserved. */
> 2022 or 2023?


Will make it as 2023.

I'm on vacation next week. I will post the V5 once I'm back.

Thanks,

Kathiravan T.


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