[PATCH v2 3/9] clk: qcom: msm8996-cpu: Add MSM8996 Pro CBF support

From: Yassine Oudjana
Date: Sat Apr 09 2022 - 00:16:41 EST


MSM8996 Pro (MSM8996SG) has a /4 divisor on the CBF clock
instead of /2. This allows it to reach a lower minimum frequency
of 192000000Hz compared to 307200000Hz on regular MSM8996.
Add support for setting the CBF clock divisor to /4 for MSM8996 Pro.

Signed-off-by: Yassine Oudjana <y.oudjana@xxxxxxxxxxxxxx>
Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxx>
---
drivers/clk/qcom/clk-cpu-8996.c | 61 +++++++++++++++++++++------------
1 file changed, 40 insertions(+), 21 deletions(-)

diff --git a/drivers/clk/qcom/clk-cpu-8996.c b/drivers/clk/qcom/clk-cpu-8996.c
index 8afc271f92d0..231d8224fa16 100644
--- a/drivers/clk/qcom/clk-cpu-8996.c
+++ b/drivers/clk/qcom/clk-cpu-8996.c
@@ -70,11 +70,11 @@ enum _pmux_input {

enum {
CBF_PLL_INDEX = 1,
- CBF_DIV_2_INDEX,
+ CBF_DIV_INDEX,
CBF_SAFE_INDEX
};

-#define DIV_2_THRESHOLD 600000000
+#define DIV_THRESHOLD 600000000
#define PWRCL_REG_OFFSET 0x0
#define PERFCL_REG_OFFSET 0x80000
#define MUX_OFFSET 0x40
@@ -142,6 +142,17 @@ static const struct alpha_pll_config cbfpll_config = {
.early_output_mask = BIT(3),
};

+static const struct alpha_pll_config cbfpll_config_pro = {
+ .l = 72,
+ .config_ctl_val = 0x200d4aa8,
+ .config_ctl_hi_val = 0x006,
+ .pre_div_mask = BIT(12),
+ .post_div_mask = 0x3 << 8,
+ .post_div_val = 0x3 << 8,
+ .main_output_mask = BIT(0),
+ .early_output_mask = BIT(3),
+};
+
static struct clk_alpha_pll perfcl_pll = {
.offset = PERFCL_REG_OFFSET,
.regs = prim_pll_regs,
@@ -230,7 +241,8 @@ struct clk_cpu_8996_mux {
u8 width;
struct notifier_block nb;
struct clk_hw *pll;
- struct clk_hw *pll_div_2;
+ struct clk_hw *pll_div;
+ u8 div;
struct clk_regmap clkr;
};

@@ -280,11 +292,11 @@ static int clk_cpu_8996_mux_determine_rate(struct clk_hw *hw,
struct clk_cpu_8996_mux *cpuclk = to_clk_cpu_8996_mux_hw(hw);
struct clk_hw *parent = cpuclk->pll;

- if (cpuclk->pll_div_2 && req->rate < DIV_2_THRESHOLD) {
- if (req->rate < (DIV_2_THRESHOLD / 2))
+ if (cpuclk->pll_div && req->rate < DIV_THRESHOLD) {
+ if (req->rate < (DIV_THRESHOLD / cpuclk->div))
return -EINVAL;

- parent = cpuclk->pll_div_2;
+ parent = cpuclk->pll_div;
}

req->best_parent_rate = clk_hw_round_rate(parent, req->rate);
@@ -336,7 +348,8 @@ static struct clk_cpu_8996_mux pwrcl_pmux = {
.shift = 0,
.width = 2,
.pll = &pwrcl_pll.clkr.hw,
- .pll_div_2 = &pwrcl_smux.clkr.hw,
+ .pll_div = &pwrcl_smux.clkr.hw,
+ .div = 2,
.nb.notifier_call = cpu_clk_notifier_cb,
.clkr.hw.init = &(struct clk_init_data) {
.name = "pwrcl_pmux",
@@ -358,7 +371,8 @@ static struct clk_cpu_8996_mux perfcl_pmux = {
.shift = 0,
.width = 2,
.pll = &perfcl_pll.clkr.hw,
- .pll_div_2 = &perfcl_smux.clkr.hw,
+ .pll_div = &perfcl_smux.clkr.hw,
+ .div = 2,
.nb.notifier_call = cpu_clk_notifier_cb,
.clkr.hw.init = &(struct clk_init_data) {
.name = "perfcl_pmux",
@@ -481,19 +495,23 @@ static int qcom_cbf_clk_msm8996_register_clks(struct device *dev,
struct regmap *regmap)
{
int ret;
+ bool is_pro = of_device_is_compatible(dev->of_node, "qcom,msm8996pro-apcc");

- cbf_mux.pll_div_2 = clk_hw_register_fixed_factor(dev, "cbf_pll_main",
- "cbf_pll", CLK_SET_RATE_PARENT,
- 1, 2);
- if (IS_ERR(cbf_mux.pll_div_2)) {
+ cbf_mux.div = is_pro ? 4 : 2;
+ cbf_mux.pll_div = clk_hw_register_fixed_factor(dev, "cbf_pll_main",
+ "cbf_pll", CLK_SET_RATE_PARENT,
+ 1, cbf_mux.div);
+
+ if (IS_ERR(cbf_mux.pll_div)) {
dev_err(dev, "Failed to initialize cbf_pll_main\n");
- return PTR_ERR(cbf_mux.pll_div_2);
+ return PTR_ERR(cbf_mux.pll_div);
}

ret = devm_clk_register_regmap(dev, cbf_msm8996_clks[0]);
ret = devm_clk_register_regmap(dev, cbf_msm8996_clks[1]);

- clk_alpha_pll_configure(&cbf_pll, regmap, &cbfpll_config);
+ clk_alpha_pll_configure(&cbf_pll, regmap, is_pro ?
+ &cbfpll_config_pro : &cbfpll_config);
clk_set_rate(cbf_pll.clkr.hw.clk, 614400000);
clk_prepare_enable(cbf_pll.clkr.hw.clk);
clk_notifier_register(cbf_mux.clkr.hw.clk, &cbf_mux.nb);
@@ -575,7 +593,7 @@ static int cpu_clk_notifier_cb(struct notifier_block *nb, unsigned long event,
qcom_cpu_clk_msm8996_acd_init(base);
break;
case POST_RATE_CHANGE:
- if (cnd->new_rate < DIV_2_THRESHOLD)
+ if (cnd->new_rate < DIV_THRESHOLD)
ret = clk_cpu_8996_mux_set_parent(&cpuclk->clkr.hw,
DIV_2_INDEX);
else
@@ -600,15 +618,15 @@ static int cbf_clk_notifier_cb(struct notifier_block *nb, unsigned long event,

switch (event) {
case PRE_RATE_CHANGE:
- parent = clk_hw_get_parent_by_index(&cbfclk->clkr.hw, CBF_DIV_2_INDEX);
- ret = clk_cpu_8996_mux_set_parent(&cbfclk->clkr.hw, CBF_DIV_2_INDEX);
+ parent = clk_hw_get_parent_by_index(&cbfclk->clkr.hw, CBF_DIV_INDEX);
+ ret = clk_cpu_8996_mux_set_parent(&cbfclk->clkr.hw, CBF_DIV_INDEX);

- if (cnd->old_rate > DIV_2_THRESHOLD && cnd->new_rate < DIV_2_THRESHOLD)
- ret = clk_set_rate(parent->clk, cnd->old_rate / 2);
+ if (cnd->old_rate > DIV_THRESHOLD && cnd->new_rate < DIV_THRESHOLD)
+ ret = clk_set_rate(parent->clk, cnd->old_rate / cbfclk->div);
break;
case POST_RATE_CHANGE:
- if (cnd->new_rate < DIV_2_THRESHOLD)
- ret = clk_cpu_8996_mux_set_parent(&cbfclk->clkr.hw, CBF_DIV_2_INDEX);
+ if (cnd->new_rate < DIV_THRESHOLD)
+ ret = clk_cpu_8996_mux_set_parent(&cbfclk->clkr.hw, CBF_DIV_INDEX);
else {
parent = clk_hw_get_parent_by_index(&cbfclk->clkr.hw, CBF_PLL_INDEX);
ret = clk_set_rate(parent->clk, cnd->new_rate);
@@ -676,6 +694,7 @@ static int qcom_cpu_clk_msm8996_driver_remove(struct platform_device *pdev)

static const struct of_device_id qcom_cpu_clk_msm8996_match_table[] = {
{ .compatible = "qcom,msm8996-apcc" },
+ { .compatible = "qcom,msm8996pro-apcc" },
{}
};
MODULE_DEVICE_TABLE(of, qcom_cpu_clk_msm8996_match_table);
--
2.35.1