Il 15/01/21 14:02, Vinod Koul ha scritto:

On 13-01-21, 23:39, AngeloGioacchino Del Regno wrote:

quoted

Il 05/01/21 16:46, Vinod Koul ha scritto:

quoted

From: Vivek Aknurwar <redacted>

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

Signed-off-by: Vivek Aknurwar <redacted>
Signed-off-by: Jeevan Shriram <redacted>
[vkoul: rebase and tidy up for upstream]
Signed-off-by: Vinod Koul <vkoul@kernel.org>
---
   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.

Yeah I agree we could reuse, I can redo this. I was thinking of making
this bit as one of the values in register and use that but that does not
look good as this is not a register offset, so only option is to have a
new type of PLL for this and use that as here..

Just an idea:

static int __alpha_pll_trion_set_rate(struct clk_hw *hw,
                                       u32 upd_regbit, u32 latch_regbit,
                                       unsigned long rate,
                                       unsigned long prate)

static int alpha_pll_trion_set_rate( args here )
{
	return __alpha_pll_trion_set_rate(hw, PLL_UPDATE,
					 ALPHA_PLL_ACK_LATCH,
					 rate, prate);
}

static int alpha_pll_lucid_5lpe_set_rate( args )
{
	return __alpha_pll_trion_set_rate(hw, LUCID_5LPE_PLL_UPDATE,
					  LUCID_5LPE_PLL_ACK_LATCH,
					  rate, prate);
}

Perhaps, that would be good.

--Angelo