[PATCH v3 3/5] clocks: exynos4x12: add runtime pm support for ISP clocks

Marek Szyprowski m.szyprowski at samsung.com
Mon Oct 24 05:12:08 PDT 2016


Exynos4412 clock controller contains some additional clocks for FIMC-ISP
(Camera ISP) subsystem. Registers for those clocks are partially located
in the SOC area, which belongs to ISP power domain.

This patch implements integration of ISP clocks with ISP power domain
by using runtime pm feature of clocks core. This finally solves all the
mysterious freezes in accessing ISP clocks when ISP power domain is disabled.

Signed-off-by: Marek Szyprowski <m.szyprowski at samsung.com>
---
 .../devicetree/bindings/clock/exynos4-clock.txt    |  22 +++
 drivers/clk/samsung/clk-exynos4.c                  | 211 +++++++++++++++------
 2 files changed, 172 insertions(+), 61 deletions(-)

diff --git a/Documentation/devicetree/bindings/clock/exynos4-clock.txt b/Documentation/devicetree/bindings/clock/exynos4-clock.txt
index f5a5b19ed3b2..429dd7e420e4 100644
--- a/Documentation/devicetree/bindings/clock/exynos4-clock.txt
+++ b/Documentation/devicetree/bindings/clock/exynos4-clock.txt
@@ -41,3 +41,25 @@ Example 2: UART controller node that consumes the clock generated by the clock
 		clocks = <&clock CLK_UART2>, <&clock CLK_SCLK_UART2>;
 		clock-names = "uart", "clk_uart_baud0";
 	};
+
+Exynos4412 clock controller contains some additional clocks for FIMC-ISP
+(Camera ISP) subsystem. Registers for those clocks are partially located
+in the SOC area, which belongs to ISP power domain. To properly handle
+additional ISP clocks and their integration with power domains, an
+additional subnode "isp-clock-controller" with "samsung,exynos4412-isp-clock"
+compatible has to be defined under the main Exynos4 clock node. This subnode
+can be then used for linking with respective ISP power domain (for more
+information, see Samsung Exynos power domains bindings).
+
+Example 3: An example of a clock controller for Exynos4412 with ISP clocks.
+
+	clock: clock-controller at 10030000 {
+		compatible = "samsung,exynos4412-clock";
+		reg = <0x10030000 0x20000>;
+		#clock-cells = <1>;
+
+		isp-clock-controller {
+			compatible = "samsung,exynos4412-isp-clock";
+			power-domains = <&pd_isp>;
+		};
+	};
diff --git a/drivers/clk/samsung/clk-exynos4.c b/drivers/clk/samsung/clk-exynos4.c
index faab9b31baf5..e5165be348ef 100644
--- a/drivers/clk/samsung/clk-exynos4.c
+++ b/drivers/clk/samsung/clk-exynos4.c
@@ -16,7 +16,10 @@
 #include <linux/clk-provider.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/of_platform.h>
 #include <linux/syscore_ops.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 
 #include "clk.h"
 #include "clk-cpu.h"
@@ -123,6 +126,8 @@
 #define CLKOUT_CMU_CPU		0x14a00
 #define PWR_CTRL1		0x15020
 #define E4X12_PWR_CTRL2		0x15024
+
+/* Exynos4x12 specific registers, which belong to ISP power domain */
 #define E4X12_DIV_ISP0		0x18300
 #define E4X12_DIV_ISP1		0x18304
 #define E4X12_GATE_ISP0		0x18800
@@ -156,6 +161,8 @@ enum exynos4_plls {
 
 static void __iomem *reg_base;
 static enum exynos4_soc exynos4_soc;
+static struct samsung_clk_provider *exynos4412_ctx;
+static struct device_node *exynos4412_clk_node;
 
 /*
  * Support for CMU save/restore across system suspends
@@ -164,6 +171,7 @@ enum exynos4_plls {
 static struct samsung_clk_reg_dump *exynos4_save_common;
 static struct samsung_clk_reg_dump *exynos4_save_soc;
 static struct samsung_clk_reg_dump *exynos4_save_pll;
+static struct samsung_clk_reg_dump *exynos4x12_save_isp;
 
 /*
  * list of controller registers to be saved and restored during a
@@ -192,6 +200,13 @@ enum exynos4_plls {
 	E4X12_PWR_CTRL2,
 };
 
+static const unsigned long exynos4x12_clk_isp_save[] __initconst = {
+	E4X12_DIV_ISP0,
+	E4X12_DIV_ISP1,
+	E4X12_GATE_ISP0,
+	E4X12_GATE_ISP1,
+};
+
 static const unsigned long exynos4_clk_pll_regs[] __initconst = {
 	EPLL_LOCK,
 	VPLL_LOCK,
@@ -822,20 +837,21 @@ static void __init exynos4_clk_sleep_init(void) {}
 	DIV(0, "div_spi1_isp", "mout_spi1_isp", E4X12_DIV_ISP, 16, 4),
 	DIV(0, "div_spi1_isp_pre", "div_spi1_isp", E4X12_DIV_ISP, 20, 8),
 	DIV(0, "div_uart_isp", "mout_uart_isp", E4X12_DIV_ISP, 28, 4),
-	DIV_F(CLK_DIV_ISP0, "div_isp0", "aclk200", E4X12_DIV_ISP0, 0, 3,
-						CLK_GET_RATE_NOCACHE, 0),
-	DIV_F(CLK_DIV_ISP1, "div_isp1", "aclk200", E4X12_DIV_ISP0, 4, 3,
-						CLK_GET_RATE_NOCACHE, 0),
-	DIV(0, "div_mpwm", "div_isp1", E4X12_DIV_ISP1, 0, 3),
-	DIV_F(CLK_DIV_MCUISP0, "div_mcuisp0", "aclk400_mcuisp", E4X12_DIV_ISP1,
-						4, 3, CLK_GET_RATE_NOCACHE, 0),
-	DIV_F(CLK_DIV_MCUISP1, "div_mcuisp1", "div_mcuisp0", E4X12_DIV_ISP1,
-						8, 3, CLK_GET_RATE_NOCACHE, 0),
 	DIV(CLK_SCLK_FIMG2D, "sclk_fimg2d", "mout_g2d", DIV_DMC1, 0, 4),
 	DIV(CLK_DIV_C2C, "div_c2c", "mout_c2c", DIV_DMC1, 4, 3),
 	DIV(0, "div_c2c_aclk", "div_c2c", DIV_DMC1, 12, 3),
 };
 
+static struct samsung_div_clock exynos4x12_isp_div_clks[] = {
+	DIV_F(CLK_DIV_ISP0, "div_isp0", "aclk200", E4X12_DIV_ISP0, 0, 3, 0, 0),
+	DIV_F(CLK_DIV_ISP1, "div_isp1", "aclk200", E4X12_DIV_ISP0, 4, 3, 0, 0),
+	DIV_F(CLK_DIV_MCUISP0, "div_mcuisp0", "aclk400_mcuisp", E4X12_DIV_ISP1,
+						4, 3, 0, 0),
+	DIV_F(CLK_DIV_MCUISP1, "div_mcuisp1", "div_mcuisp0", E4X12_DIV_ISP1,
+						8, 3, 0, 0),
+	DIV_F(0, "div_mpwm", "div_isp1", E4X12_DIV_ISP1, 0, 3, 0, 0),
+};
+
 /* list of gate clocks supported in all exynos4 soc's */
 static const struct samsung_gate_clock exynos4_gate_clks[] __initconst = {
 	/*
@@ -1132,64 +1148,41 @@ static void __init exynos4_clk_sleep_init(void) {}
 			0, 0),
 	GATE(CLK_I2S0, "i2s0", "aclk100", E4X12_GATE_IP_MAUDIO, 3,
 			0, 0),
-	GATE(CLK_FIMC_ISP, "isp", "aclk200", E4X12_GATE_ISP0, 0,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_FIMC_DRC, "drc", "aclk200", E4X12_GATE_ISP0, 1,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_FIMC_FD, "fd", "aclk200", E4X12_GATE_ISP0, 2,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_FIMC_LITE0, "lite0", "aclk200", E4X12_GATE_ISP0, 3,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_FIMC_LITE1, "lite1", "aclk200", E4X12_GATE_ISP0, 4,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_MCUISP, "mcuisp", "aclk200", E4X12_GATE_ISP0, 5,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_GICISP, "gicisp", "aclk200", E4X12_GATE_ISP0, 7,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_SMMU_ISP, "smmu_isp", "aclk200", E4X12_GATE_ISP0, 8,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_SMMU_DRC, "smmu_drc", "aclk200", E4X12_GATE_ISP0, 9,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_SMMU_FD, "smmu_fd", "aclk200", E4X12_GATE_ISP0, 10,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_SMMU_LITE0, "smmu_lite0", "aclk200", E4X12_GATE_ISP0, 11,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_SMMU_LITE1, "smmu_lite1", "aclk200", E4X12_GATE_ISP0, 12,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_PPMUISPMX, "ppmuispmx", "aclk200", E4X12_GATE_ISP0, 20,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_PPMUISPX, "ppmuispx", "aclk200", E4X12_GATE_ISP0, 21,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_MCUCTL_ISP, "mcuctl_isp", "aclk200", E4X12_GATE_ISP0, 23,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_MPWM_ISP, "mpwm_isp", "aclk200", E4X12_GATE_ISP0, 24,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_I2C0_ISP, "i2c0_isp", "aclk200", E4X12_GATE_ISP0, 25,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_I2C1_ISP, "i2c1_isp", "aclk200", E4X12_GATE_ISP0, 26,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_MTCADC_ISP, "mtcadc_isp", "aclk200", E4X12_GATE_ISP0, 27,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_PWM_ISP, "pwm_isp", "aclk200", E4X12_GATE_ISP0, 28,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_WDT_ISP, "wdt_isp", "aclk200", E4X12_GATE_ISP0, 30,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_UART_ISP, "uart_isp", "aclk200", E4X12_GATE_ISP0, 31,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_ASYNCAXIM, "asyncaxim", "aclk200", E4X12_GATE_ISP1, 0,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_SMMU_ISPCX, "smmu_ispcx", "aclk200", E4X12_GATE_ISP1, 4,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_SPI0_ISP, "spi0_isp", "aclk200", E4X12_GATE_ISP1, 12,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
-	GATE(CLK_SPI1_ISP, "spi1_isp", "aclk200", E4X12_GATE_ISP1, 13,
-			CLK_IGNORE_UNUSED | CLK_GET_RATE_NOCACHE, 0),
 	GATE(CLK_G2D, "g2d", "aclk200", GATE_IP_DMC, 23, 0, 0),
 	GATE(CLK_SMMU_G2D, "smmu_g2d", "aclk200", GATE_IP_DMC, 24, 0, 0),
 	GATE(CLK_TMU_APBIF, "tmu_apbif", "aclk100", E4X12_GATE_IP_PERIR, 17, 0,
 		0),
 };
 
+static struct samsung_gate_clock exynos4x12_isp_gate_clks[] = {
+	GATE(CLK_FIMC_ISP, "isp", "aclk200", E4X12_GATE_ISP0, 0, 0, 0),
+	GATE(CLK_FIMC_DRC, "drc", "aclk200", E4X12_GATE_ISP0, 1, 0, 0),
+	GATE(CLK_FIMC_FD, "fd", "aclk200", E4X12_GATE_ISP0, 2, 0, 0),
+	GATE(CLK_FIMC_LITE0, "lite0", "aclk200", E4X12_GATE_ISP0, 3, 0, 0),
+	GATE(CLK_FIMC_LITE1, "lite1", "aclk200", E4X12_GATE_ISP0, 4, 0, 0),
+	GATE(CLK_MCUISP, "mcuisp", "aclk200", E4X12_GATE_ISP0, 5, 0, 0),
+	GATE(CLK_GICISP, "gicisp", "aclk200", E4X12_GATE_ISP0, 7, 0, 0),
+	GATE(CLK_SMMU_ISP, "smmu_isp", "aclk200", E4X12_GATE_ISP0, 8, 0, 0),
+	GATE(CLK_SMMU_DRC, "smmu_drc", "aclk200", E4X12_GATE_ISP0, 9, 0, 0),
+	GATE(CLK_SMMU_FD, "smmu_fd", "aclk200", E4X12_GATE_ISP0, 10, 0, 0),
+	GATE(CLK_SMMU_LITE0, "smmu_lite0", "aclk200", E4X12_GATE_ISP0, 11, 0, 0),
+	GATE(CLK_SMMU_LITE1, "smmu_lite1", "aclk200", E4X12_GATE_ISP0, 12, 0, 0),
+	GATE(CLK_PPMUISPMX, "ppmuispmx", "aclk200", E4X12_GATE_ISP0, 20, 0, 0),
+	GATE(CLK_PPMUISPX, "ppmuispx", "aclk200", E4X12_GATE_ISP0, 21, 0, 0),
+	GATE(CLK_MCUCTL_ISP, "mcuctl_isp", "aclk200", E4X12_GATE_ISP0, 23, 0, 0),
+	GATE(CLK_MPWM_ISP, "mpwm_isp", "aclk200", E4X12_GATE_ISP0, 24, 0, 0),
+	GATE(CLK_I2C0_ISP, "i2c0_isp", "aclk200", E4X12_GATE_ISP0, 25, 0, 0),
+	GATE(CLK_I2C1_ISP, "i2c1_isp", "aclk200", E4X12_GATE_ISP0, 26, 0, 0),
+	GATE(CLK_MTCADC_ISP, "mtcadc_isp", "aclk200", E4X12_GATE_ISP0, 27, 0, 0),
+	GATE(CLK_PWM_ISP, "pwm_isp", "aclk200", E4X12_GATE_ISP0, 28, 0, 0),
+	GATE(CLK_WDT_ISP, "wdt_isp", "aclk200", E4X12_GATE_ISP0, 30, 0, 0),
+	GATE(CLK_UART_ISP, "uart_isp", "aclk200", E4X12_GATE_ISP0, 31, 0, 0),
+	GATE(CLK_ASYNCAXIM, "asyncaxim", "aclk200", E4X12_GATE_ISP1, 0, 0, 0),
+	GATE(CLK_SMMU_ISPCX, "smmu_ispcx", "aclk200", E4X12_GATE_ISP1, 4, 0, 0),
+	GATE(CLK_SPI0_ISP, "spi0_isp", "aclk200", E4X12_GATE_ISP1, 12, 0, 0),
+	GATE(CLK_SPI1_ISP, "spi1_isp", "aclk200", E4X12_GATE_ISP1, 13, 0, 0),
+};
+
 static const struct samsung_clock_alias exynos4_aliases[] __initconst = {
 	ALIAS(CLK_MOUT_CORE, NULL, "moutcore"),
 	ALIAS(CLK_ARM_CLK, NULL, "armclk"),
@@ -1438,6 +1431,100 @@ static void __init exynos4x12_core_down_clock(void)
 	{  0 },
 };
 
+static int exynos4x12_isp_clk_suspend(struct device *dev)
+{
+	samsung_clk_save(reg_base, exynos4x12_save_isp,
+				ARRAY_SIZE(exynos4x12_clk_isp_save));
+	return 0;
+}
+
+static int exynos4x12_isp_clk_resume(struct device *dev)
+{
+	samsung_clk_restore(reg_base, exynos4x12_save_isp,
+				ARRAY_SIZE(exynos4x12_clk_isp_save));
+	return 0;
+}
+
+static int __init exynos4x12_isp_clk_probe(struct platform_device *pdev)
+{
+	struct samsung_clk_provider *ctx = exynos4412_ctx;
+
+	if (!ctx)
+		return -ENODEV;
+
+	exynos4x12_save_isp = samsung_clk_alloc_reg_dump(exynos4x12_clk_isp_save,
+					ARRAY_SIZE(exynos4x12_clk_isp_save));
+	if (!exynos4x12_save_isp)
+		return -ENOMEM;
+
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
+	ctx->dev = &pdev->dev;
+
+	samsung_clk_register_div(ctx, exynos4x12_isp_div_clks,
+		ARRAY_SIZE(exynos4x12_isp_div_clks));
+	samsung_clk_register_gate(ctx, exynos4x12_isp_gate_clks,
+		ARRAY_SIZE(exynos4x12_isp_gate_clks));
+
+	return 0;
+}
+
+static const struct of_device_id exynos4x12_isp_clk_of_match[] = {
+	{ .compatible = "samsung,exynos4412-isp-clock", },
+	{ },
+};
+
+static const struct dev_pm_ops exynos4x12_isp_pm_ops = {
+	SET_RUNTIME_PM_OPS(exynos4x12_isp_clk_suspend,
+			   exynos4x12_isp_clk_resume, NULL)
+	SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				     pm_runtime_force_resume)
+};
+
+static struct platform_driver exynos4x12_isp_clk_driver __refdata = {
+	.driver	= {
+		.name = "exynos-isp-clk",
+		.of_match_table = exynos4x12_isp_clk_of_match,
+		.suppress_bind_attrs = true,
+		.pm = &exynos4x12_isp_pm_ops,
+	},
+	.probe = exynos4x12_isp_clk_probe,
+};
+
+static int __init exynos4x12_isp_clk_init(void)
+{
+	if (!exynos4412_clk_node)
+		return 0;
+
+	of_platform_populate(exynos4412_clk_node, NULL, NULL, NULL);
+	return platform_driver_register(&exynos4x12_isp_clk_driver);
+}
+arch_initcall(exynos4x12_isp_clk_init);
+
+static void __init exynos4x12_isp_defer_clocks(struct samsung_clk_provider *ctx,
+					       struct device_node *parent)
+{
+	struct device_node *np = of_get_next_available_child(parent, NULL);
+	if (!np)
+		return;
+
+	if (of_device_is_compatible(np,
+		    exynos4x12_isp_clk_of_match[0].compatible)) {
+		int i;
+
+		for (i = 0; i < ARRAY_SIZE(exynos4x12_isp_div_clks); i++)
+			samsung_clk_add_lookup(ctx, ERR_PTR(-EPROBE_DEFER),
+					       exynos4x12_isp_div_clks[i].id);
+		for (i = 0; i < ARRAY_SIZE(exynos4x12_isp_gate_clks); i++)
+			samsung_clk_add_lookup(ctx, ERR_PTR(-EPROBE_DEFER),
+					       exynos4x12_isp_gate_clks[i].id);
+		exynos4412_ctx = ctx;
+		exynos4412_clk_node = parent;
+	}
+	of_node_put(np);
+}
+
 /* register exynos4 clocks */
 static void __init exynos4_clk_init(struct device_node *np,
 				    enum exynos4_soc soc)
@@ -1529,6 +1616,8 @@ static void __init exynos4_clk_init(struct device_node *np,
 		samsung_clk_register_fixed_factor(ctx,
 			exynos4x12_fixed_factor_clks,
 			ARRAY_SIZE(exynos4x12_fixed_factor_clks));
+		exynos4x12_isp_defer_clocks(ctx, np);
+
 		if (of_machine_is_compatible("samsung,exynos4412")) {
 			exynos_register_cpu_clock(ctx, CLK_ARM_CLK, "armclk",
 				mout_core_p4x12[0], mout_core_p4x12[1], 0x14200,
-- 
1.9.1




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