[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <940a744c-ca5d-4edd-8a90-be2f8c7da7c0@linaro.org>
Date: Tue, 7 Jan 2025 14:36:52 +0100
From: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
Cc: Bjorn Andersson <andersson@...nel.org>,
Michael Turquette <mturquette@...libre.com>, Stephen Boyd
<sboyd@...nel.org>, Rob Herring <robh@...nel.org>,
Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley
<conor+dt@...nel.org>, Neil Armstrong <neil.armstrong@...aro.org>,
linux-arm-msm@...r.kernel.org, linux-clk@...r.kernel.org,
devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/3] clk: qcom: clk-alpha-pll: Add Pongo PLL
On 07/01/2025 13:36, Dmitry Baryshkov wrote:
> On Mon, Jan 06, 2025 at 02:44:30PM +0100, Krzysztof Kozlowski wrote:
>> Add support for Pongo type of PLL clocks, used in Qualcomm SM8750 SoC.
>> Notable difference comparing to other PLLs is the need for calibration
>> for internally generated clock followed by wait_for_pll(). This is done
>> in configure call and at this time clocks are not yet registered, thus
>> wait_for_pll() cannot use clk_hw_get_name.
>
> Is this still correct?
No, it is not, I forgot to drop it after reworking code.
Patches were merged, though.
>
>> Locking during this
>> calibration requires much more time, thus increase the timeout in
>> wait_for_pll().
>>
>> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
>>
>> ---
>>
>> v2:
>> - EXPORT_SYMBOL_GPL
>> - Move the PLL calibration and wait_for_pll_enable_lock() call to
>> prepare callback.
>> ---
>> drivers/clk/qcom/clk-alpha-pll.c | 165 ++++++++++++++++++++++++++++++++++++++-
>> drivers/clk/qcom/clk-alpha-pll.h | 6 ++
>> 2 files changed, 170 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/clk/qcom/clk-alpha-pll.c b/drivers/clk/qcom/clk-alpha-pll.c
>> index 00d3659ea2124e26dd50c1b4e88ba71c1411442e..df609f7e394de2dc73e60df01b1ad71714c0719d 100644
>> --- a/drivers/clk/qcom/clk-alpha-pll.c
>> +++ b/drivers/clk/qcom/clk-alpha-pll.c
>> @@ -58,6 +58,7 @@
>> #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_TEST_CTL_U2(p) ((p)->offset + (p)->regs[PLL_OFF_TEST_CTL_U2])
>> +#define PLL_TEST_CTL_U3(p) ((p)->offset + (p)->regs[PLL_OFF_TEST_CTL_U3])
>> #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])
>> @@ -197,6 +198,23 @@ const u8 clk_alpha_pll_regs[][PLL_OFF_MAX_REGS] = {
>> [PLL_OFF_TEST_CTL_U1] = 0x34,
>> [PLL_OFF_TEST_CTL_U2] = 0x38,
>> },
>> + [CLK_ALPHA_PLL_TYPE_PONGO_ELU] = {
>> + [PLL_OFF_OPMODE] = 0x04,
>> + [PLL_OFF_STATE] = 0x08,
>> + [PLL_OFF_STATUS] = 0x0c,
>> + [PLL_OFF_L_VAL] = 0x10,
>> + [PLL_OFF_USER_CTL] = 0x14,
>> + [PLL_OFF_USER_CTL_U] = 0x18,
>> + [PLL_OFF_CONFIG_CTL] = 0x1c,
>> + [PLL_OFF_CONFIG_CTL_U] = 0x20,
>> + [PLL_OFF_CONFIG_CTL_U1] = 0x24,
>> + [PLL_OFF_CONFIG_CTL_U2] = 0x28,
>> + [PLL_OFF_TEST_CTL] = 0x2c,
>> + [PLL_OFF_TEST_CTL_U] = 0x30,
>> + [PLL_OFF_TEST_CTL_U1] = 0x34,
>> + [PLL_OFF_TEST_CTL_U2] = 0x38,
>> + [PLL_OFF_TEST_CTL_U3] = 0x3c,
>> + },
>> [CLK_ALPHA_PLL_TYPE_TAYCAN_ELU] = {
>> [PLL_OFF_OPMODE] = 0x04,
>> [PLL_OFF_STATE] = 0x08,
>> @@ -337,6 +355,12 @@ EXPORT_SYMBOL_GPL(clk_alpha_pll_regs);
>> #define LUCID_EVO_PLL_CAL_L_VAL_SHIFT 16
>> #define LUCID_OLE_PLL_RINGOSC_CAL_L_VAL_SHIFT 24
>>
>> +/* PONGO ELU PLL specific setting and offsets */
>> +#define PONGO_PLL_OUT_MASK GENMASK(1, 0)
>> +#define PONGO_PLL_L_VAL_MASK GENMASK(11, 0)
>
> Does it really support such a high L value, or are there any additional
> flags / data entries? PLL2 uses 0x493, which should end up with 22 GHz
> clock, if my calculations are correct.
That's the bitfield also in datasheet (except downstream driver). Not
exactly answer to "does it really support", but not sure what else we
can do here.
>
>> +#define PONGO_XO_PRESENT BIT(10)
>> +#define PONGO_CLOCK_SELECT BIT(12)
>> +
>> /* ZONDA PLL specific */
>> #define ZONDA_PLL_OUT_MASK 0xf
>> #define ZONDA_STAY_IN_CFA BIT(16)
>> @@ -366,7 +390,8 @@ static int wait_for_pll(struct clk_alpha_pll *pll, u32 mask, bool inverse,
>> if (ret)
>> return ret;
>>
>> - for (count = 200; count > 0; count--) {
>> + /* Pongo PLLs using a 32KHz reference can take upwards of 1500us to lock. */
>> + for (count = 1500; count > 0; count--) {
>> ret = regmap_read(pll->clkr.regmap, PLL_MODE(pll), &val);
>> if (ret)
>> return ret;
>> @@ -2527,6 +2552,144 @@ const struct clk_ops clk_alpha_pll_reset_lucid_evo_ops = {
>> };
>> EXPORT_SYMBOL_GPL(clk_alpha_pll_reset_lucid_evo_ops);
>>
>> +static int alpha_pll_pongo_elu_prepare(struct clk_hw *hw)
>> +{
>> + struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
>> + struct regmap *regmap = pll->clkr.regmap;
>> + int ret;
>> +
>> + /* Enable PLL intially to one-time calibrate against XO. */
>> + regmap_write(regmap, PLL_OPMODE(pll), PLL_RUN);
>> + regmap_update_bits(regmap, PLL_MODE(pll), PLL_RESET_N, PLL_RESET_N);
>> + regmap_update_bits(regmap, PLL_MODE(pll), PONGO_XO_PRESENT, PONGO_XO_PRESENT);
>> +
>> + /* Set regmap for wait_for_pll() */
>> + pll->clkr.regmap = regmap;
>> + ret = wait_for_pll_enable_lock(pll);
>> + if (ret) {
>> + /* Reverse calibration - disable PLL output */
>> + regmap_update_bits(regmap, PLL_MODE(pll), PLL_OUTCTRL, 0);
>> + return ret;
>> + }
>> +
>> + /* Disable PLL after one-time calibration. */
>> + regmap_write(regmap, PLL_OPMODE(pll), PLL_STANDBY);
>> +
>> + /* Select internally generated clock. */
>> + regmap_update_bits(regmap, PLL_MODE(pll), PONGO_CLOCK_SELECT,
>> + PONGO_CLOCK_SELECT);
>> +
>> + return 0;
>> +}
>> +
>> +static int alpha_pll_pongo_elu_enable(struct clk_hw *hw)
>> +{
>> + struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
>> + struct regmap *regmap = pll->clkr.regmap;
>> + int ret;
>> +
>> + /* Check if PLL is already enabled */
>> + if (trion_pll_is_enabled(pll, regmap))
>> + return 0;
>> +
>> + ret = regmap_update_bits(regmap, PLL_MODE(pll), PLL_RESET_N, PLL_RESET_N);
>> + if (ret)
>> + return ret;
>> +
>> + /* Set operation mode to RUN */
>> + regmap_write(regmap, PLL_OPMODE(pll), PLL_RUN);
>> +
>> + ret = wait_for_pll_enable_lock(pll);
>> + if (ret)
>> + return ret;
>> +
>> + /* Enable the global PLL outputs */
>> + ret = regmap_update_bits(regmap, PLL_MODE(pll), PLL_OUTCTRL, PLL_OUTCTRL);
>> + if (ret)
>> + return ret;
>> +
>> + /* Ensure that the write above goes through before returning. */
>> + mb();
>> +
>> + return ret;
>> +}
>> +
>> +static void alpha_pll_pongo_elu_disable(struct clk_hw *hw)
>> +{
>> + struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
>> + struct regmap *regmap = pll->clkr.regmap;
>> + int ret;
>> +
>> + /* Disable the global PLL output */
>> + ret = regmap_update_bits(regmap, PLL_MODE(pll), PLL_OUTCTRL, 0);
>> + if (ret)
>> + return;
>> +
>> + /* Place the PLL mode in STANDBY */
>> + regmap_write(regmap, PLL_OPMODE(pll), PLL_STANDBY);
>> +}
>> +
>> +static unsigned long alpha_pll_pongo_elu_recalc_rate(struct clk_hw *hw,
>> + unsigned long parent_rate)
>> +{
>> + struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
>> + struct regmap *regmap = pll->clkr.regmap;
>> + u32 l;
>> +
>> + if (regmap_read(regmap, PLL_L_VAL(pll), &l))
>> + return 0;
>> +
>> + l &= PONGO_PLL_L_VAL_MASK;
>> +
>> + return alpha_pll_calc_rate(parent_rate, l, 0, pll_alpha_width(pll));
>> +}
>> +
>> +const struct clk_ops clk_alpha_pll_pongo_elu_ops = {
>> + .prepare = alpha_pll_pongo_elu_prepare,
>> + .enable = alpha_pll_pongo_elu_enable,
>> + .disable = alpha_pll_pongo_elu_disable,
>> + .recalc_rate = alpha_pll_pongo_elu_recalc_rate,
>> +};
>> +EXPORT_SYMBOL_GPL(clk_alpha_pll_pongo_elu_ops);
>> +
>> +void clk_pongo_elu_pll_configure(struct clk_alpha_pll *pll,
>> + struct regmap *regmap,
>> + const struct alpha_pll_config *config)
>> +{
>> + u32 val;
>> +
>> + regmap_update_bits(regmap, PLL_USER_CTL(pll), PONGO_PLL_OUT_MASK,
>> + PONGO_PLL_OUT_MASK);
>> +
>> + if (trion_pll_is_enabled(pll, regmap))
>> + return;
>> +
>> + if (regmap_read(regmap, PLL_L_VAL(pll), &val))
>> + return;
>> + val &= PONGO_PLL_L_VAL_MASK;
>> + if (val)
>> + return;
>> +
>> + clk_alpha_pll_write_config(regmap, PLL_L_VAL(pll), config->l);
>> + clk_alpha_pll_write_config(regmap, PLL_ALPHA_VAL(pll), config->alpha);
>> + clk_alpha_pll_write_config(regmap, PLL_CONFIG_CTL(pll), config->config_ctl_val);
>> + clk_alpha_pll_write_config(regmap, PLL_CONFIG_CTL_U(pll), config->config_ctl_hi_val);
>> + clk_alpha_pll_write_config(regmap, PLL_CONFIG_CTL_U1(pll), config->config_ctl_hi1_val);
>> + clk_alpha_pll_write_config(regmap, PLL_CONFIG_CTL_U2(pll), config->config_ctl_hi2_val);
>> + clk_alpha_pll_write_config(regmap, PLL_USER_CTL(pll),
>> + config->user_ctl_val | PONGO_PLL_OUT_MASK);
>> + clk_alpha_pll_write_config(regmap, PLL_USER_CTL_U(pll), config->user_ctl_hi_val);
>> + clk_alpha_pll_write_config(regmap, PLL_TEST_CTL(pll), config->test_ctl_val);
>> + clk_alpha_pll_write_config(regmap, PLL_TEST_CTL_U(pll), config->test_ctl_hi_val);
>> + clk_alpha_pll_write_config(regmap, PLL_TEST_CTL_U1(pll), config->test_ctl_hi1_val);
>> + clk_alpha_pll_write_config(regmap, PLL_TEST_CTL_U2(pll), config->test_ctl_hi2_val);
>> + clk_alpha_pll_write_config(regmap, PLL_TEST_CTL_U3(pll), config->test_ctl_hi3_val);
>> +
>> + /* Disable PLL output */
>> + regmap_update_bits(regmap, PLL_MODE(pll), PLL_OUTCTRL, 0);
>> +}
>> +EXPORT_SYMBOL_GPL(clk_pongo_elu_pll_configure);
>> +
>> void clk_rivian_evo_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
>> const struct alpha_pll_config *config)
>> {
>> diff --git a/drivers/clk/qcom/clk-alpha-pll.h b/drivers/clk/qcom/clk-alpha-pll.h
>> index 87bd469d9c2c2ec4e0758c97231527b92fe6afe5..79aca8525262211ae5295245427d4540abf1e09a 100644
>> --- a/drivers/clk/qcom/clk-alpha-pll.h
>> +++ b/drivers/clk/qcom/clk-alpha-pll.h
>> @@ -27,6 +27,7 @@ enum {
>> CLK_ALPHA_PLL_TYPE_ZONDA_OLE,
>> CLK_ALPHA_PLL_TYPE_LUCID_EVO,
>> CLK_ALPHA_PLL_TYPE_LUCID_OLE,
>> + CLK_ALPHA_PLL_TYPE_PONGO_ELU,
>> CLK_ALPHA_PLL_TYPE_TAYCAN_ELU,
>> CLK_ALPHA_PLL_TYPE_RIVIAN_EVO,
>> CLK_ALPHA_PLL_TYPE_DEFAULT_EVO,
>> @@ -53,6 +54,7 @@ enum {
>> PLL_OFF_TEST_CTL_U,
>> PLL_OFF_TEST_CTL_U1,
>> PLL_OFF_TEST_CTL_U2,
>> + PLL_OFF_TEST_CTL_U3,
>> PLL_OFF_STATE,
>> PLL_OFF_STATUS,
>> PLL_OFF_OPMODE,
>> @@ -138,6 +140,7 @@ struct alpha_pll_config {
>> u32 test_ctl_hi_mask;
>> u32 test_ctl_hi1_val;
>> u32 test_ctl_hi2_val;
>> + u32 test_ctl_hi3_val;
>> u32 main_output_mask;
>> u32 aux_output_mask;
>> u32 aux2_output_mask;
>> @@ -196,6 +199,7 @@ extern const struct clk_ops clk_alpha_pll_postdiv_lucid_evo_ops;
>> #define clk_alpha_pll_postdiv_lucid_ole_ops clk_alpha_pll_postdiv_lucid_evo_ops
>> #define clk_alpha_pll_postdiv_taycan_elu_ops clk_alpha_pll_postdiv_lucid_evo_ops
>>
>> +extern const struct clk_ops clk_alpha_pll_pongo_elu_ops;
>> extern const struct clk_ops clk_alpha_pll_rivian_evo_ops;
>> #define clk_alpha_pll_postdiv_rivian_evo_ops clk_alpha_pll_postdiv_fabia_ops
>>
>> @@ -222,6 +226,8 @@ void clk_lucid_evo_pll_configure(struct clk_alpha_pll *pll, struct regmap *regma
>> const struct alpha_pll_config *config);
>> void clk_lucid_ole_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
>> const struct alpha_pll_config *config);
>> +void clk_pongo_elu_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
>> + const struct alpha_pll_config *config);
>> #define clk_taycan_elu_pll_configure(pll, regmap, config) \
>> clk_lucid_evo_pll_configure(pll, regmap, config)
>>
>>
>> --
>> 2.43.0
>>
>
Best regards,
Krzysztof
Powered by blists - more mailing lists