[PATCH v2 4/5] clk: qcom: clk-alpha-pll: Add support for Lucid 5LPE PLL

From: Vinod Koul
Date: Tue Dec 08 2020 - 01:48:21 EST


From: Vivek Aknurwar <viveka@xxxxxxxxxxxxxx>

Lucid 5LPE is a slightly different Lucid PLL with different offsets and
porgramming sequence so add support for these

Signed-off-by: Vivek Aknurwar <viveka@xxxxxxxxxxxxxx>
Signed-off-by: Jeevan Shriram <jshriram@xxxxxxxxxxxxxx>
[vkoul: rebase and tidy up for upstream]
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
---
drivers/clk/qcom/clk-alpha-pll.c | 223 +++++++++++++++++++++++++++++++
drivers/clk/qcom/clk-alpha-pll.h | 4 +
2 files changed, 227 insertions(+)

diff --git a/drivers/clk/qcom/clk-alpha-pll.c b/drivers/clk/qcom/clk-alpha-pll.c
index 564431130a76..6a399663d564 100644
--- a/drivers/clk/qcom/clk-alpha-pll.c
+++ b/drivers/clk/qcom/clk-alpha-pll.c
@@ -146,6 +146,12 @@ EXPORT_SYMBOL_GPL(clk_alpha_pll_regs);
/* LUCID PLL specific settings and offsets */
#define LUCID_PCAL_DONE BIT(27)

+/* LUCID 5LPE PLL specific settings and offsets */
+#define LUCID_5LPE_PCAL_DONE BIT(11)
+#define LUCID_5LPE_ENABLE_VOTE_RUN BIT(21)
+#define LUCID_5LPE_PLL_LATCH_INPUT BIT(14)
+#define LUCID_5LPE_ALPHA_PLL_ACK_LATCH BIT(13)
+
#define pll_alpha_width(p) \
((PLL_ALPHA_VAL_U(p) - PLL_ALPHA_VAL(p) == 4) ? \
ALPHA_REG_BITWIDTH : ALPHA_REG_16BIT_WIDTH)
@@ -1561,3 +1567,220 @@ const struct clk_ops clk_alpha_pll_postdiv_lucid_ops = {
.set_rate = clk_alpha_pll_postdiv_fabia_set_rate,
};
EXPORT_SYMBOL_GPL(clk_alpha_pll_postdiv_lucid_ops);
+
+static int alpha_pll_lucid_5lpe_enable(struct clk_hw *hw)
+{
+ struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
+ u32 val;
+ int ret;
+
+ ret = regmap_read(pll->clkr.regmap, PLL_USER_CTL(pll), &val);
+ if (ret)
+ return ret;
+
+ /* If in FSM mode, just vote for it */
+ if (val & LUCID_5LPE_ENABLE_VOTE_RUN) {
+ ret = clk_enable_regmap(hw);
+ if (ret)
+ return ret;
+ return wait_for_pll_enable_lock(pll);
+ }
+
+ /* Check if PLL is already enabled */
+ ret = trion_pll_is_enabled(pll, pll->clkr.regmap);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_update_bits(pll->clkr.regmap, PLL_MODE(pll), PLL_RESET_N, PLL_RESET_N);
+ if (ret)
+ return ret;
+
+ /* Set operation mode to RUN */
+ regmap_write(pll->clkr.regmap, PLL_OPMODE(pll), PLL_RUN);
+
+ ret = wait_for_pll_enable_lock(pll);
+ if (ret)
+ return ret;
+
+ /* Enable the PLL outputs */
+ ret = regmap_update_bits(pll->clkr.regmap, PLL_USER_CTL(pll), PLL_OUT_MASK, PLL_OUT_MASK);
+ if (ret)
+ return ret;
+
+ /* Enable the global PLL outputs */
+ ret = regmap_update_bits(pll->clkr.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_lucid_5lpe_disable(struct clk_hw *hw)
+{
+ struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
+ u32 val;
+ int ret;
+
+ ret = regmap_read(pll->clkr.regmap, PLL_USER_CTL(pll), &val);
+ if (ret)
+ return;
+
+ /* If in FSM mode, just unvote it */
+ if (val & LUCID_5LPE_ENABLE_VOTE_RUN) {
+ clk_disable_regmap(hw);
+ return;
+ }
+
+ /* Disable the global PLL output */
+ ret = regmap_update_bits(pll->clkr.regmap, PLL_MODE(pll), PLL_OUTCTRL, 0);
+ if (ret)
+ return;
+
+ /* Disable the PLL outputs */
+ ret = regmap_update_bits(pll->clkr.regmap, PLL_USER_CTL(pll), PLL_OUT_MASK, 0);
+ if (ret)
+ return;
+
+ /* Place the PLL mode in STANDBY */
+ regmap_write(pll->clkr.regmap, PLL_OPMODE(pll), PLL_STANDBY);
+}
+
+/*
+ * The Lucid 5LPE PLL requires a power-on self-calibration which happens
+ * when the PLL comes out of reset. Calibrate in case it is not completed.
+ */
+static int alpha_pll_lucid_5lpe_prepare(struct clk_hw *hw)
+{
+ struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
+ struct clk_hw *p;
+ u32 regval;
+ int ret;
+
+ /* Return early if calibration is not needed. */
+ regmap_read(pll->clkr.regmap, PLL_MODE(pll), &regval);
+ if (regval & LUCID_5LPE_PCAL_DONE)
+ return 0;
+
+ p = clk_hw_get_parent(hw);
+ if (!p)
+ return -EINVAL;
+
+ ret = alpha_pll_lucid_5lpe_enable(hw);
+ if (ret)
+ return ret;
+
+ alpha_pll_lucid_5lpe_disable(hw);
+
+ return 0;
+}
+
+static int alpha_pll_lucid_5lpe_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long prate)
+{
+ struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
+ unsigned long rrate;
+ u32 regval, l;
+ u64 a;
+ int ret;
+
+ rrate = alpha_pll_round_rate(rate, prate, &l, &a, ALPHA_REG_16BIT_WIDTH);
+
+ /*
+ * Due to a limited number of bits for fractional rate programming, the
+ * rounded up rate could be marginally higher than the requested rate.
+ */
+ if (rrate > (rate + PLL_RATE_MARGIN) || rrate < rate) {
+ pr_err("Call set rate on the PLL with rounded rates!\n");
+ return -EINVAL;
+ }
+
+ regmap_write(pll->clkr.regmap, PLL_L_VAL(pll), l);
+ regmap_write(pll->clkr.regmap, PLL_ALPHA_VAL(pll), a);
+
+ /* Latch the PLL input */
+ ret = regmap_update_bits(pll->clkr.regmap, PLL_MODE(pll),
+ LUCID_5LPE_PLL_LATCH_INPUT, LUCID_5LPE_PLL_LATCH_INPUT);
+ if (ret)
+ return ret;
+
+ /* Wait for 2 reference cycles before checking the ACK bit. */
+ udelay(1);
+ regmap_read(pll->clkr.regmap, PLL_MODE(pll), &regval);
+ if (!(regval & LUCID_5LPE_ALPHA_PLL_ACK_LATCH)) {
+ pr_err("Lucid 5LPE PLL latch failed. Output may be unstable!\n");
+ return -EINVAL;
+ }
+
+ /* Return the latch input to 0 */
+ ret = regmap_update_bits(pll->clkr.regmap, PLL_MODE(pll), LUCID_5LPE_PLL_LATCH_INPUT, 0);
+ if (ret)
+ return ret;
+
+ if (clk_hw_is_enabled(hw)) {
+ ret = wait_for_pll_enable_lock(pll);
+ if (ret)
+ return ret;
+ }
+
+ /* Wait for PLL output to stabilize */
+ udelay(100);
+ return 0;
+}
+
+static int clk_lucid_5lpe_pll_postdiv_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_alpha_pll_postdiv *pll = to_clk_alpha_pll_postdiv(hw);
+ int i, val = 0, div, ret;
+
+ /*
+ * If the PLL is in FSM mode, then treat set_rate callback as a
+ * no-operation.
+ */
+ ret = regmap_read(pll->clkr.regmap, PLL_USER_CTL(pll), &val);
+ if (ret)
+ return ret;
+
+ if (val & LUCID_5LPE_ENABLE_VOTE_RUN)
+ return 0;
+
+ if (!pll->post_div_table) {
+ pr_err("Missing the post_div_table for the PLL\n");
+ return -EINVAL;
+ }
+
+ div = DIV_ROUND_UP_ULL((u64)parent_rate, rate);
+ for (i = 0; i < pll->num_post_div; i++) {
+ if (pll->post_div_table[i].div == div) {
+ val = pll->post_div_table[i].val;
+ break;
+ }
+ }
+
+ return regmap_update_bits(pll->clkr.regmap, PLL_USER_CTL(pll),
+ (BIT(pll->width) - 1) << pll->post_div_shift,
+ val << pll->post_div_shift);
+}
+
+const struct clk_ops clk_alpha_pll_lucid_5lpe_ops = {
+ .prepare = alpha_pll_lucid_5lpe_prepare,
+ .enable = alpha_pll_lucid_5lpe_enable,
+ .disable = alpha_pll_lucid_5lpe_disable,
+ .set_rate = alpha_pll_lucid_5lpe_set_rate,
+};
+EXPORT_SYMBOL_GPL(clk_alpha_pll_lucid_5lpe_ops);
+
+const struct clk_ops clk_alpha_pll_fixed_lucid_5lpe_ops = {
+ .enable = alpha_pll_lucid_5lpe_enable,
+ .disable = alpha_pll_lucid_5lpe_disable,
+};
+EXPORT_SYMBOL_GPL(clk_alpha_pll_fixed_lucid_5lpe_ops);
+
+const struct clk_ops clk_alpha_pll_postdiv_lucid_5lpe_ops = {
+ .recalc_rate = clk_alpha_pll_postdiv_fabia_recalc_rate,
+ .round_rate = clk_alpha_pll_postdiv_fabia_round_rate,
+ .set_rate = clk_lucid_5lpe_pll_postdiv_set_rate,
+};
+EXPORT_SYMBOL_GPL(clk_alpha_pll_postdiv_lucid_5lpe_ops);
diff --git a/drivers/clk/qcom/clk-alpha-pll.h b/drivers/clk/qcom/clk-alpha-pll.h
index d3201b87c0cd..d983b1aab8c8 100644
--- a/drivers/clk/qcom/clk-alpha-pll.h
+++ b/drivers/clk/qcom/clk-alpha-pll.h
@@ -142,6 +142,10 @@ extern const struct clk_ops clk_alpha_pll_lucid_ops;
#define clk_alpha_pll_fixed_lucid_ops clk_alpha_pll_fixed_trion_ops
extern const struct clk_ops clk_alpha_pll_postdiv_lucid_ops;

+extern const struct clk_ops clk_alpha_pll_lucid_5lpe_ops;
+extern const struct clk_ops clk_alpha_pll_fixed_lucid_5lpe_ops;
+extern const struct clk_ops clk_alpha_pll_postdiv_lucid_5lpe_ops;
+
void clk_alpha_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
const struct alpha_pll_config *config);
void clk_fabia_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
--
2.26.2