Re: [PATCH V4] clk: qcom: clk-alpha-pll: Add support for Stromer PLLs
From: Kathiravan Thirumoorthy
Date: Fri Jan 13 2023 - 08:44:28 EST
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.