[PATCH 4/5] clk: samsung: Add support for EPLL on exynos5410

From: Sylwester Nawrocki <s.nawrocki@samsung.com>
To: linux-clk@vger.kernel.org
Cc: tomasz.figa@gmail.com, sboyd@codeaurora.org,
	mturquette@baylibre.com, kgene@kernel.org,
	k.kozlowski@samsung.com, b.zolnierkie@samsung.com,
	linux-samsung-soc@vger.kernel.org,
	Sylwester Nawrocki <s.nawrocki@samsung.com>
Subject: [PATCH 4/5] clk: samsung: Add support for EPLL on exynos5410
Date: Mon, 22 Aug 2016 18:31:02 +0200	[thread overview]
Message-ID: <1471883463-1950-5-git-send-email-s.nawrocki@samsung.com> (raw)
In-Reply-To: <1471883463-1950-1-git-send-email-s.nawrocki@samsung.com>

This patch adds code instantiating the EPLL, which is used as the
audio subsystem's root clock.
The requirement to specify the external root clock in clocks property
is also added.  That ensures proper initialization order by explicitly
specifying dependencies in devicetree.  It prevents situations when the
SoC's clock controller driver has initialized, the external oscillator
clock is not yet registered and setting clock frequencies through
assigned-clock-rates property doesn't work properly due to unknown
external oscillator frequency.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
---
 .../devicetree/bindings/clock/exynos5410-clock.txt |  14 +++
 drivers/clk/samsung/clk-exynos5410.c               |  30 +++++-
 drivers/clk/samsung/clk-pll.c                      | 102 +++++++++++++++++++++
 drivers/clk/samsung/clk-pll.h                      |   1 +
 4 files changed, 145 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/clock/exynos5410-clock.txt b/Documentation/devicetree/bindings/clock/exynos5410-clock.txt
index aeab635..2aefc07 100644
--- a/Documentation/devicetree/bindings/clock/exynos5410-clock.txt
+++ b/Documentation/devicetree/bindings/clock/exynos5410-clock.txt
@@ -12,6 +12,9 @@ Required Properties:
 
 - #clock-cells: should be 1.
 
+- clocks: should contain an entry specifying the root oscillator clock
+  on XXTI pin (fin_pll).
+
 All available clocks are defined as preprocessor macros in
 dt-bindings/clock/exynos5410.h header and can be used in device
 tree sources.
@@ -24,12 +27,23 @@ with following clock-output-name:
 
  - "fin_pll" - PLL input clock from XXTI
 
+This clock should be listed in the clocks property of the controller node.
+
+
 Example 1: An example of a clock controller node is listed below.
 
+	fin_pll: xxti {
+		compatible = "fixed-clock";
+		clock-frequency = <24000000>;
+		clock-output-names = "fin_pll";
+		#clock-cells = <0>;
+	};
+
 	clock: clock-controller@0x10010000 {
 		compatible = "samsung,exynos5410-clock";
 		reg = <0x10010000 0x30000>;
 		#clock-cells = <1>;
+		clocks = <&fin_pll>;
 	};
 
 Example 2: UART controller node that consumes the clock generated by the clock
diff --git a/drivers/clk/samsung/clk-exynos5410.c b/drivers/clk/samsung/clk-exynos5410.c
index cf6fb41..113ce7d 100644
--- a/drivers/clk/samsung/clk-exynos5410.c
+++ b/drivers/clk/samsung/clk-exynos5410.c
@@ -14,6 +14,7 @@
 #include <linux/clk-provider.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/clk.h>
 
 #include "clk.h"
 
@@ -21,6 +22,8 @@
 #define APLL_CON0               0x100
 #define CPLL_LOCK               0x10020
 #define CPLL_CON0               0x10120
+#define EPLL_LOCK               0x10040
+#define EPLL_CON0               0x10130
 #define MPLL_LOCK               0x4000
 #define MPLL_CON0               0x4100
 #define BPLL_LOCK               0x20010
@@ -58,7 +61,7 @@
 
 /* list of PLLs */
 enum exynos5410_plls {
-	apll, cpll, mpll,
+	apll, cpll, epll, mpll,
 	bpll, kpll,
 	nr_plls                 /* number of PLLs */
 };
@@ -67,6 +70,7 @@ enum exynos5410_plls {
 PNAME(apll_p)		= { "fin_pll", "fout_apll", };
 PNAME(bpll_p)		= { "fin_pll", "fout_bpll", };
 PNAME(cpll_p)		= { "fin_pll", "fout_cpll" };
+PNAME(epll_p)		= { "fin_pll", "fout_epll" };
 PNAME(mpll_p)		= { "fin_pll", "fout_mpll", };
 PNAME(kpll_p)		= { "fin_pll", "fout_kpll", };
 
@@ -95,6 +99,8 @@ static const struct samsung_mux_clock exynos5410_mux_clks[] __initconst = {
 	MUX(0, "sclk_bpll", bpll_p, SRC_CDREX, 0, 1),
 	MUX(0, "sclk_bpll_muxed", bpll_user_p, SRC_TOP2, 24, 1),
 
+	MUX(0, "sclk_epll", epll_p, SRC_TOP2, 12, 1),
+
 	MUX(0, "sclk_cpll", cpll_p, SRC_TOP2, 8, 1),
 
 	MUX(0, "sclk_mpll_bpll", mpll_bpll_p, SRC_TOP1, 20, 1),
@@ -219,11 +225,26 @@ static const struct samsung_gate_clock exynos5410_gate_clks[] __initconst = {
 	GATE(CLK_USBD301, "usbd301", "aclk200_fsys", GATE_IP_FSYS, 20, 0, 0),
 };
 
-static const struct samsung_pll_clock exynos5410_plls[nr_plls] __initconst = {
+static const struct samsung_pll_rate_table exynos5410_pll2550x_24mhz_tbl[] __initconst = {
+	PLL_36XX_RATE(400000000U, 200, 2, 2, 0),
+	PLL_36XX_RATE(333000000U, 111, 2, 2, 0),
+	PLL_36XX_RATE(300000000U, 100, 2, 2, 0),
+	PLL_36XX_RATE(266000000U, 266, 3, 3, 0),
+	PLL_36XX_RATE(200000000U, 200, 3, 3, 0),
+	PLL_36XX_RATE(192000000U, 192, 3, 3, 0),
+	PLL_36XX_RATE(166000000U, 166, 3, 3, 0),
+	PLL_36XX_RATE(133000000U, 266, 3, 4, 0),
+	PLL_36XX_RATE(100000000U, 200, 3, 4, 0),
+	PLL_36XX_RATE(66000000U,  176, 2, 5, 0),
+};
+
+static struct samsung_pll_clock exynos5410_plls[nr_plls] __initdata = {
 	[apll] = PLL(pll_35xx, CLK_FOUT_APLL, "fout_apll", "fin_pll", APLL_LOCK,
 		APLL_CON0, NULL),
 	[cpll] = PLL(pll_35xx, CLK_FOUT_CPLL, "fout_cpll", "fin_pll", CPLL_LOCK,
 		CPLL_CON0, NULL),
+	[epll] = PLL(pll_2650x, CLK_FOUT_EPLL, "fout_epll", "fin_pll", EPLL_LOCK,
+		EPLL_CON0, NULL),
 	[mpll] = PLL(pll_35xx, CLK_FOUT_MPLL, "fout_mpll", "fin_pll", MPLL_LOCK,
 		MPLL_CON0, NULL),
 	[bpll] = PLL(pll_35xx, CLK_FOUT_BPLL, "fout_bpll", "fin_pll", BPLL_LOCK,
@@ -237,6 +258,7 @@ static void __init exynos5410_clk_init(struct device_node *np)
 {
 	struct samsung_clk_provider *ctx;
 	void __iomem *reg_base;
+	struct clk *xxti;
 
 	reg_base = of_iomap(np, 0);
 	if (!reg_base)
@@ -244,6 +266,10 @@ static void __init exynos5410_clk_init(struct device_node *np)
 
 	ctx = samsung_clk_init(np, reg_base, CLK_NR_CLKS);
 
+	xxti = of_clk_get(np, 0);
+	if (!IS_ERR(xxti) && clk_get_rate(xxti) == 24 * MHZ)
+		exynos5410_plls[epll].rate_table = exynos5410_pll2550x_24mhz_tbl;
+
 	samsung_clk_register_pll(ctx, exynos5410_plls,
 			ARRAY_SIZE(exynos5410_plls), reg_base);
 
diff --git a/drivers/clk/samsung/clk-pll.c b/drivers/clk/samsung/clk-pll.c
index b5ab055..d61fd80 100644
--- a/drivers/clk/samsung/clk-pll.c
+++ b/drivers/clk/samsung/clk-pll.c
@@ -1018,6 +1018,102 @@ static const struct clk_ops samsung_pll2550xx_clk_min_ops = {
 };
 
 /*
+ * PLL2650x Clock Type
+ */
+
+/* Maximum lock time can be 3000 * PDIV cycles */
+#define PLL2650X_LOCK_FACTOR		3000
+
+#define PLL2650X_M_MASK			0x3FF
+#define PLL2650X_P_MASK			0x3F
+#define PLL2650X_S_MASK			0x7
+#define PLL2650X_K_MASK			0xFFFF
+#define PLL2650X_LOCK_STAT_MASK		0x1
+#define PLL2650X_M_SHIFT		16
+#define PLL2650X_P_SHIFT		8
+#define PLL2650X_S_SHIFT		0
+#define PLL2650X_K_SHIFT		0
+#define PLL2650X_LOCK_STAT_SHIFT	29
+#define PLL2650X_PLL_ENABLE_SHIFT	31
+
+static unsigned long samsung_pll2650x_recalc_rate(struct clk_hw *hw,
+				unsigned long parent_rate)
+{
+	struct samsung_clk_pll *pll = to_clk_pll(hw);
+	u64 fout = parent_rate;
+	u32 mdiv, pdiv, sdiv, pll_con0, pll_con1;
+	s16 kdiv;
+
+	pll_con0 = readl_relaxed(pll->con_reg);
+	mdiv = (pll_con0 >> PLL2650X_M_SHIFT) & PLL2650X_M_MASK;
+	pdiv = (pll_con0 >> PLL2650X_P_SHIFT) & PLL2650X_P_MASK;
+	sdiv = (pll_con0 >> PLL2650X_S_SHIFT) & PLL2650X_S_MASK;
+
+	pll_con1 = readl_relaxed(pll->con_reg + 4);
+	kdiv = (s16)((pll_con1 >> PLL2650X_K_SHIFT) & PLL2650X_K_MASK);
+
+	fout *= (mdiv << 16) + kdiv;
+	do_div(fout, (pdiv << sdiv));
+	fout >>= 16;
+
+	return (unsigned long)fout;
+}
+
+static int samsung_pll2650x_set_rate(struct clk_hw *hw, unsigned long drate,
+					unsigned long prate)
+{
+	struct samsung_clk_pll *pll = to_clk_pll(hw);
+	const struct samsung_pll_rate_table *rate;
+	u32 con0, con1;
+
+	/* Get required rate settings from table */
+	rate = samsung_get_pll_settings(pll, drate);
+	if (!rate) {
+		pr_err("%s: Invalid rate : %lu for pll clk %s\n", __func__,
+			drate, clk_hw_get_name(hw));
+		return -EINVAL;
+	}
+
+	con0 = readl_relaxed(pll->con_reg);
+	con1 = readl_relaxed(pll->con_reg + 4);
+
+	/* Set PLL lock time. */
+	writel_relaxed(rate->pdiv * PLL2650X_LOCK_FACTOR, pll->lock_reg);
+
+	/* Change PLL PMS values */
+	con0 &= ~((PLL2650X_M_MASK << PLL2650X_M_SHIFT) |
+			(PLL2650X_P_MASK << PLL2650X_P_SHIFT) |
+			(PLL2650X_S_MASK << PLL2650X_S_SHIFT));
+	con0 |= (rate->mdiv << PLL2650X_M_SHIFT) |
+			(rate->pdiv << PLL2650X_P_SHIFT) |
+			(rate->sdiv << PLL2650X_S_SHIFT);
+	con0 |= (1 << PLL2650X_PLL_ENABLE_SHIFT);
+	writel_relaxed(con0, pll->con_reg);
+
+	con1 &= ~(PLL2650X_K_MASK << PLL2650X_K_SHIFT);
+	con1 |= ((rate->kdiv & PLL2650X_K_MASK) << PLL2650X_K_SHIFT);
+	writel_relaxed(con1, pll->con_reg + 4);
+
+	do {
+		cpu_relax();
+		con0 = readl_relaxed(pll->con_reg);
+	} while (!(con0 & (PLL2650X_LOCK_STAT_MASK
+			<< PLL2650X_LOCK_STAT_SHIFT)));
+
+	return 0;
+}
+
+static const struct clk_ops samsung_pll2650x_clk_ops = {
+	.recalc_rate = samsung_pll2650x_recalc_rate,
+	.round_rate = samsung_pll_round_rate,
+	.set_rate = samsung_pll2650x_set_rate,
+};
+
+static const struct clk_ops samsung_pll2650x_clk_min_ops = {
+	.recalc_rate = samsung_pll2650x_recalc_rate,
+};
+
+/*
  * PLL2650XX Clock Type
  */
 
@@ -1227,6 +1323,12 @@ static void __init _samsung_clk_register_pll(struct samsung_clk_provider *ctx,
 		else
 			init.ops = &samsung_pll2550xx_clk_ops;
 		break;
+	case pll_2650x:
+		if (!pll->rate_table)
+			init.ops = &samsung_pll2650x_clk_min_ops;
+		else
+			init.ops = &samsung_pll2650x_clk_ops;
+		break;
 	case pll_2650xx:
 		if (!pll->rate_table)
 			init.ops = &samsung_pll2650xx_clk_min_ops;
diff --git a/drivers/clk/samsung/clk-pll.h b/drivers/clk/samsung/clk-pll.h
index df4ad8a..a1ca023 100644
--- a/drivers/clk/samsung/clk-pll.h
+++ b/drivers/clk/samsung/clk-pll.h
@@ -33,6 +33,7 @@ enum samsung_pll_type {
 	pll_s3c2440_mpll,
 	pll_2550x,
 	pll_2550xx,
+	pll_2650x,
 	pll_2650xx,
 	pll_1450x,
 	pll_1451x,
-- 
1.9.1
