Re: [PATCH 2/4] clk: qcom: clk-alpha-pll: Add support for Lucid 5LPE PLL
From: AngeloGioacchino Del Regno
Date: Wed Jan 13 2021 - 18:09:35 EST
Il 05/01/21 16:46, Vinod Koul ha scritto:
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 | 217 +++++++++++++++++++++++++++++++
drivers/clk/qcom/clk-alpha-pll.h | 4 +
2 files changed, 221 insertions(+)
diff --git a/drivers/clk/qcom/clk-alpha-pll.c b/drivers/clk/qcom/clk-alpha-pll.c
index f7721088494c..843c43649a5a 100644
--- a/drivers/clk/qcom/clk-alpha-pll.c
+++ b/drivers/clk/qcom/clk-alpha-pll.c
@@ -156,6 +156,12 @@ 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_ALPHA_PLL_ACK_LATCH BIT(13)
+#define LUCID_5LPE_PLL_LATCH_INPUT BIT(14)
+#define LUCID_5LPE_ENABLE_VOTE_RUN BIT(21)
+
#define pll_alpha_width(p) \
((PLL_ALPHA_VAL_U(p) - PLL_ALPHA_VAL(p) == 4) ? \
ALPHA_REG_BITWIDTH : ALPHA_REG_16BIT_WIDTH)
@@ -1600,3 +1606,214 @@ const struct clk_ops clk_alpha_pll_agera_ops = {
.set_rate = clk_alpha_pll_agera_set_rate,
};
EXPORT_SYMBOL_GPL(clk_alpha_pll_agera_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, return if 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;
+
+ 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 */
+ return regmap_update_bits(pll->clkr.regmap, PLL_MODE(pll), PLL_OUTCTRL, PLL_OUTCTRL);
+}
+
+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 val;
+ int ret;
+
+ /* Return early if calibration is not needed. */
+ regmap_read(pll->clkr.regmap, PLL_MODE(pll), &val);
+ if (val & 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 val, 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.
+ */
+ ret = alpha_pll_check_rate_margin(hw, rrate, rate);
+ if (ret)
+ return ret;
+
+ 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), &val);
+ if (!(val & 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;
+}
+
This one looks exactly like alpha_pll_trion_set_rate() but:
1. You are forcing ALPHA_REG_16BIT_WIDTH for the alpha_pll_round_rate
call: this is bad, you should actually use pll_alpha_width(pll) here,
unless you have a very good reason that I didn't understand...
2. The only change between these two functions (trion and
lucid_5lpe_set_rate) is that PLL_UPDATE becomes
LUCID_5LPE_PLL_LATCH_INPUT, and that you check for
LUCID_5LPE_ALPHA_PLL_ACK_LATCH instead of ALPHA_PLL_ACK_LATCH: this
looks like being 95% code duplication.
The best options here, in my opinion, would be to commonize the function
alpha_pll_trion_set_rate: that will avoid this huge duplication.
+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;
+ u32 mask;
+
+ /*
+ * 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;
+
+ 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;
+ }
+ }
+
+ mask = GENMASK(pll->width + pll->post_div_shift - 1, pll->post_div_shift);
+ return regmap_update_bits(pll->clkr.regmap, PLL_USER_CTL(pll),
+ mask, 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,
+ .is_enabled = clk_trion_pll_is_enabled,
+ .recalc_rate = clk_trion_pll_recalc_rate,
+ .round_rate = clk_alpha_pll_round_rate,
+ .set_rate = alpha_pll_lucid_5lpe_set_rate,
+};
+EXPORT_SYMBOL(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,
+ .is_enabled = clk_trion_pll_is_enabled,
+ .recalc_rate = clk_trion_pll_recalc_rate,
+ .round_rate = clk_alpha_pll_round_rate,
+};
+EXPORT_SYMBOL(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(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 0ea30d2f3da1..6943e933be0f 100644
--- a/drivers/clk/qcom/clk-alpha-pll.h
+++ b/drivers/clk/qcom/clk-alpha-pll.h
@@ -144,6 +144,10 @@ extern const struct clk_ops clk_alpha_pll_lucid_ops;
extern const struct clk_ops clk_alpha_pll_postdiv_lucid_ops;
extern const struct clk_ops clk_alpha_pll_agera_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,