[PATCH 1/7] clk: qcom: clk-alpha-pll: Add support for Stromer PLLs

Varadarajan Narayanan
2020-09-28T05:18:17Z

Add programming sequence support for managing the Stromer
PLLs.

Signed-off-by: Varadarajan Narayanan <varada@codeaurora.org>
---
drivers/clk/qcom/clk-alpha-pll.c | 156 ++++++++++++++++++++++++++++++++++++++-
drivers/clk/qcom/clk-alpha-pll.h | 5 ++
2 files changed, 160 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/qcom/clk-alpha-pll.c b/drivers/clk/qcom/clk-alpha-pll.c
index 26139ef..ce3257f 100644
--- a/drivers/clk/qcom/clk-alpha-pll.c
+++ b/drivers/clk/qcom/clk-alpha-pll.c
@@ -116,6 +116,19 @@ const u8 clk_alpha_pll_regs[][PLL_OFF_MAX_REGS] = {
[PLL_OFF_OPMODE] = 0x38,
[PLL_OFF_ALPHA_VAL] = 0x40,
},
+
+ [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);

@@ -127,6 +140,8 @@ EXPORT_SYMBOL_GPL(clk_alpha_pll_regs);
#define ALPHA_BITWIDTH 32U
#define ALPHA_SHIFT(w) min(w, ALPHA_BITWIDTH)

+#define PLL_STATUS_REG_SHIFT 8
+
#define PLL_HUAYRA_M_WIDTH 8
#define PLL_HUAYRA_M_SHIFT 8
#define PLL_HUAYRA_M_MASK 0xff
@@ -210,7 +225,7 @@ static int wait_for_pll(struct clk_alpha_pll *pll, u32 mask, bool inverse,
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);
@@ -240,14 +255,143 @@ 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 */
+ val_u = config->status_reg_val << PLL_STATUS_REG_SHIFT;
+ val_u |= config->lock_det;
+
+ mask_u = config->status_reg_mask;
+ mask_u |= config->lock_det;
+
+ if (val_u != 0)
+ regmap_update_bits(regmap, PLL_USER_CTL_U(pll), mask_u, val_u);
+
+ if (config->test_ctl_val != 0)
+ regmap_write(regmap, PLL_TEST_CTL(pll), config->test_ctl_val);
+
+ if (config->test_ctl_hi_val != 0)
+ 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 unsigned long
+alpha_pll_stromer_calc_rate(u64 prate, u32 l, u64 a)
+{
+ return (prate * l) + ((prate * a) >> ALPHA_REG_BITWIDTH);
+}
+
+static unsigned long
+alpha_pll_stromer_round_rate(unsigned long rate, unsigned long prate, u32 *l, u64 *a)
+{
+ u64 remainder;
+ u64 quotient;
+
+ quotient = rate;
+ remainder = do_div(quotient, prate);
+ *l = quotient;
+
+ if (!remainder) {
+ *a = 0;
+ return rate;
+ }
+
+ quotient = remainder << ALPHA_REG_BITWIDTH;
+
+ remainder = do_div(quotient, prate);
+
+ if (remainder)
+ quotient++;
+
+ *a = quotient;
+ return alpha_pll_stromer_calc_rate(prate, *l, *a);
+}
+
+static unsigned long
+clk_alpha_pll_stromer_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
+{
+ u32 l, low, high, ctl;
+ u64 a = 0, prate = parent_rate;
+ struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
+
+ regmap_read(pll->clkr.regmap, PLL_L_VAL(pll), &l);
+
+ regmap_read(pll->clkr.regmap, PLL_USER_CTL(pll), &ctl);
+ if (ctl & PLL_ALPHA_EN) {
+ regmap_read(pll->clkr.regmap, PLL_ALPHA_VAL(pll), &low);
+ regmap_read(pll->clkr.regmap, PLL_ALPHA_VAL_U(pll),
+ &high);
+ a = (u64)high << ALPHA_BITWIDTH | low;
+ }
+
+ return alpha_pll_stromer_calc_rate(prate, l, a);
+}
+
+static int clk_alpha_pll_stromer_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ unsigned long rate = req->rate;
+ u32 l;
+ u64 a;
+
+ rate = alpha_pll_stromer_round_rate(rate, req->best_parent_rate, &l, &a);
+
+ 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_stromer_round_rate(rate, prate, &l, &a);
+
+ /* Write desired values to registers */
+ 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.
+ */
+
+ regmap_update_bits(pll->clkr.regmap, PLL_MODE(pll), PLL_UPDATE,
+ PLL_UPDATE);
+ /* Make sure PLL_UPDATE request goes through */
+ mb();
+
+ /* Wait for PLL_UPDATE to be cleared */
+ ret = wait_for_pll_update(pll);
+ if (ret)
+ return ret;
+
+ /* Wait 11or more PLL clk_ref ticks[to be explored more on wait] */
+
+ /* Poll LOCK_DET for one */
+ ret = wait_for_pll_enable_lock(pll);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
static int clk_alpha_pll_hwfsm_enable(struct clk_hw *hw)
{
int ret;
@@ -898,6 +1042,16 @@ 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_stromer_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 d3201b8..3e25b1b 100644
--- a/drivers/clk/qcom/clk-alpha-pll.h
+++ b/drivers/clk/qcom/clk-alpha-pll.h
@@ -15,6 +15,7 @@ enum {
CLK_ALPHA_PLL_TYPE_FABIA,
CLK_ALPHA_PLL_TYPE_TRION,
CLK_ALPHA_PLL_TYPE_LUCID = CLK_ALPHA_PLL_TYPE_TRION,
+ CLK_ALPHA_PLL_TYPE_STROMER,
CLK_ALPHA_PLL_TYPE_MAX,
};

@@ -121,6 +122,9 @@ struct alpha_pll_config {
u32 post_div_mask;
u32 vco_val;
u32 vco_mask;
+ u32 status_reg_val;
+ u32 status_reg_mask;
+ u32 lock_det;
};

extern const struct clk_ops clk_alpha_pll_ops;
@@ -129,6 +133,7 @@ extern const struct clk_ops clk_alpha_pll_hwfsm_ops;
extern const struct clk_ops clk_alpha_pll_postdiv_ops;
extern const struct clk_ops clk_alpha_pll_huayra_ops;
extern const struct clk_ops clk_alpha_pll_postdiv_ro_ops;
+extern const struct clk_ops clk_alpha_pll_stromer_ops;

extern const struct clk_ops clk_alpha_pll_fabia_ops;
extern const struct clk_ops clk_alpha_pll_fixed_fabia_ops;
--
2.7.4