Thread (23 messages) 23 messages, 6 authors, 2024-02-23

Re: [PATCH 3/8] clk: qcom: clk-alpha-pll: Add HUAYRA_2290 support

From: Andrew Halaney <hidden>
Date: 2024-02-19 14:54:44
Also in: dri-devel, linux-arm-msm, linux-clk, linux-devicetree, linux-iommu, lkml

On Mon, Feb 19, 2024 at 02:35:48PM +0100, Konrad Dybcio wrote:
quoted hunk ↗ jump to hunk
Commit 134b55b7e19f ("clk: qcom: support Huayra type Alpha PLL")
introduced an entry to the alpha offsets array, but diving into QCM2290
downstream and some documentation, it turned out that the name Huayra
apparently has been used quite liberally across many chips, even with
noticeably different hardware.

Introduce another set of offsets and a new configure function for the
Huayra PLL found on QCM2290. This is required e.g. for the consumers
of GPUCC_PLL0 to properly start.

Signed-off-by: Konrad Dybcio <redacted>
---
 drivers/clk/qcom/clk-alpha-pll.c | 45 ++++++++++++++++++++++++++++++++++++++++
 drivers/clk/qcom/clk-alpha-pll.h |  3 +++
 2 files changed, 48 insertions(+)
diff --git a/drivers/clk/qcom/clk-alpha-pll.c b/drivers/clk/qcom/clk-alpha-pll.c
index 8a412ef47e16..61b5abd13782 100644
--- a/drivers/clk/qcom/clk-alpha-pll.c
+++ b/drivers/clk/qcom/clk-alpha-pll.c
@@ -244,6 +244,19 @@ const u8 clk_alpha_pll_regs[][PLL_OFF_MAX_REGS] = {
 		[PLL_OFF_OPMODE] = 0x30,
 		[PLL_OFF_STATUS] = 0x3c,
 	},
+	[CLK_ALPHA_PLL_TYPE_HUAYRA_2290] =  {
+		[PLL_OFF_L_VAL] = 0x04,
+		[PLL_OFF_ALPHA_VAL] = 0x08,
+		[PLL_OFF_USER_CTL] = 0x0c,
+		[PLL_OFF_CONFIG_CTL] = 0x10,
+		[PLL_OFF_CONFIG_CTL_U] = 0x14,
+		[PLL_OFF_CONFIG_CTL_U1] = 0x18,
+		[PLL_OFF_TEST_CTL] = 0x1c,
+		[PLL_OFF_TEST_CTL_U] = 0x20,
+		[PLL_OFF_TEST_CTL_U1] = 0x24,
+		[PLL_OFF_OPMODE] = 0x28,
+		[PLL_OFF_STATUS] = 0x38,
+	},
 };
 EXPORT_SYMBOL_GPL(clk_alpha_pll_regs);
 
@@ -779,6 +792,38 @@ static long clk_alpha_pll_round_rate(struct clk_hw *hw, unsigned long rate,
 	return clamp(rate, min_freq, max_freq);
 }
 
+void clk_huayra_2290_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
+				   const struct alpha_pll_config *config)
+{
+	clk_alpha_pll_write_config(regmap, PLL_CONFIG_CTL(pll), config->config_ctl_val);
+	clk_alpha_pll_write_config(regmap, PLL_CONFIG_CTL_U(pll), config->config_ctl_hi_val);
+	clk_alpha_pll_write_config(regmap, PLL_CONFIG_CTL_U1(pll), config->config_ctl_hi1_val);
+	clk_alpha_pll_write_config(regmap, PLL_TEST_CTL(pll), config->test_ctl_val);
+	clk_alpha_pll_write_config(regmap, PLL_TEST_CTL_U(pll), config->test_ctl_hi_val);
+	clk_alpha_pll_write_config(regmap, PLL_TEST_CTL_U1(pll), config->test_ctl_hi1_val);
+	clk_alpha_pll_write_config(regmap, PLL_L_VAL(pll), config->l);
+	clk_alpha_pll_write_config(regmap, PLL_ALPHA_VAL(pll), config->alpha);
+	clk_alpha_pll_write_config(regmap, PLL_USER_CTL(pll), config->user_ctl_val);
+
+	/* Set PLL_BYPASSNL */
+	regmap_update_bits(regmap, PLL_MODE(pll), PLL_BYPASSNL, PLL_BYPASSNL);
+
+	/* Wait 5 us between setting BYPASS and deasserting reset */
+	mb();
+	udelay(5);
+
+	/* Take PLL out from reset state */
+	regmap_update_bits(regmap, PLL_MODE(pll), PLL_RESET_N, PLL_RESET_N);
+
+	/* Wait 50us for PLL_LOCK_DET bit to go high */
+	mb();
+	usleep_range(50, 55);
I *think* you'd want to use a read to ensure your write goes through
prior to your sleep... from memory-barriers.txt:

	5. A readX() by a CPU thread from the peripheral will complete before
	   any subsequent delay() loop can begin execution on the same thread.
	   This ensures that two MMIO register writes by the CPU to a peripheral
	   will arrive at least 1us apart if the first write is immediately read
	   back with readX() and udelay(1) is called prior to the second
	   writeX():

		writel(42, DEVICE_REGISTER_0); // Arrives at the device...
		readl(DEVICE_REGISTER_0);
		udelay(1);
		writel(42, DEVICE_REGISTER_1); // ...at least 1us before this.

also https://youtu.be/i6DayghhA8Q?si=7lp0be35q1HRmlnV&t=1677
for more references on this topic.

quoted hunk ↗ jump to hunk
+
+	/* Enable PLL output */
+	regmap_update_bits(regmap, PLL_MODE(pll), PLL_OUTCTRL, PLL_OUTCTRL);
+}
+EXPORT_SYMBOL(clk_huayra_2290_pll_configure);
+
 static unsigned long
 alpha_huayra_pll_calc_rate(u64 prate, u32 l, u32 a)
 {
diff --git a/drivers/clk/qcom/clk-alpha-pll.h b/drivers/clk/qcom/clk-alpha-pll.h
index fb6d50263bb9..91d3d6f19eae 100644
--- a/drivers/clk/qcom/clk-alpha-pll.h
+++ b/drivers/clk/qcom/clk-alpha-pll.h
@@ -29,6 +29,7 @@ enum {
 	CLK_ALPHA_PLL_TYPE_BRAMMO_EVO,
 	CLK_ALPHA_PLL_TYPE_STROMER,
 	CLK_ALPHA_PLL_TYPE_STROMER_PLUS,
+	CLK_ALPHA_PLL_TYPE_HUAYRA_2290,
 	CLK_ALPHA_PLL_TYPE_MAX,
 };
 
@@ -191,6 +192,8 @@ extern const struct clk_ops clk_alpha_pll_rivian_evo_ops;
 
 void clk_alpha_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
 			     const struct alpha_pll_config *config);
+void clk_huayra_2290_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,
 				const struct alpha_pll_config *config);
 void clk_trion_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
-- 
2.43.2

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