[PATCH v4 3/4] drivers: exynos-srom: Add support for bank configuration

Pavel Fedin p.fedin at samsung.com
Thu Oct 29 05:42:19 PDT 2015


Implement handling properties in subnodes and adding child devices to the
system. Child devices will not be added if configuration fails.

Since the driver now does more than suspend-resume support, dependency on
CONFIG_PM is removed.

Signed-off-by: Pavel Fedin <p.fedin at samsung.com>
---
 arch/arm/mach-exynos/Kconfig      |  2 +-
 drivers/soc/samsung/Kconfig       |  2 +-
 drivers/soc/samsung/exynos-srom.c | 58 +++++++++++++++++++++++++++++++++++++--
 3 files changed, 58 insertions(+), 4 deletions(-)

diff --git a/arch/arm/mach-exynos/Kconfig b/arch/arm/mach-exynos/Kconfig
index 83c85f5..c22dc42 100644
--- a/arch/arm/mach-exynos/Kconfig
+++ b/arch/arm/mach-exynos/Kconfig
@@ -16,7 +16,7 @@ menuconfig ARCH_EXYNOS
 	select ARM_GIC
 	select COMMON_CLK_SAMSUNG
 	select EXYNOS_THERMAL
-	select EXYNOS_SROM if PM
+	select EXYNOS_SROM
 	select HAVE_ARM_SCU if SMP
 	select HAVE_S3C2410_I2C if I2C
 	select HAVE_S3C2410_WATCHDOG if WATCHDOG
diff --git a/drivers/soc/samsung/Kconfig b/drivers/soc/samsung/Kconfig
index 2833b5b..ea4bc2a 100644
--- a/drivers/soc/samsung/Kconfig
+++ b/drivers/soc/samsung/Kconfig
@@ -8,6 +8,6 @@ config SOC_SAMSUNG
 
 config EXYNOS_SROM
 	bool
-	depends on ARM && ARCH_EXYNOS && PM
+	depends on ARM && ARCH_EXYNOS
 
 endmenu
diff --git a/drivers/soc/samsung/exynos-srom.c b/drivers/soc/samsung/exynos-srom.c
index 57a232d..68e894f 100644
--- a/drivers/soc/samsung/exynos-srom.c
+++ b/drivers/soc/samsung/exynos-srom.c
@@ -14,6 +14,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 
@@ -67,11 +68,48 @@ static struct exynos_srom_reg_dump *exynos_srom_alloc_reg_dump(
 	return rd;
 }
 
+static int decode_sromc(struct exynos_srom *srom, struct device_node *np)
+{
+	u32 bank, width;
+	u32 timing[7];
+	u32 cs, bw;
+
+	if (of_property_read_u32(np, "samsung,srom-bank", &bank))
+		return -EINVAL;
+	if (of_property_read_u32(np, "samsung,srom-data-width", &width))
+		width = 1;
+	if (of_property_read_u32_array(np, "samsung,srom-timing", timing,
+				       ARRAY_SIZE(timing)))
+		return -EINVAL;
+
+	bank *= 4; /* Convert bank into shift/offset */
+
+	cs = 1 << EXYNOS_SROM_BW__BYTEENABLE__SHIFT;
+	if (width == 2)
+		cs |= 1 << EXYNOS_SROM_BW__DATAWIDTH__SHIFT;
+
+	bw = __raw_readl(srom->reg_base + EXYNOS_SROM_BW);
+	bw = (bw & ~(EXYNOS_SROM_BW__CS_MASK << bank)) | (cs << bank);
+	__raw_writel(bw, srom->reg_base + EXYNOS_SROM_BW);
+
+	__raw_writel((timing[0] << EXYNOS_SROM_BCX__PMC__SHIFT) |
+		    (timing[1] << EXYNOS_SROM_BCX__TACP__SHIFT) |
+		    (timing[2] << EXYNOS_SROM_BCX__TCAH__SHIFT) |
+		    (timing[3] << EXYNOS_SROM_BCX__TCOH__SHIFT) |
+		    (timing[4] << EXYNOS_SROM_BCX__TACC__SHIFT) |
+		    (timing[5] << EXYNOS_SROM_BCX__TCOS__SHIFT) |
+		    (timing[6] << EXYNOS_SROM_BCX__TACS__SHIFT),
+		    srom->reg_base + EXYNOS_SROM_BC0 + bank);
+
+	return 0;
+}
+
 static int exynos_srom_probe(struct platform_device *pdev)
 {
-	struct device_node *np;
+	struct device_node *np, *child;
 	struct exynos_srom *srom;
 	struct device *dev = &pdev->dev;
+	bool error = false;
 
 	np = dev->of_node;
 	if (!np) {
@@ -100,7 +138,23 @@ static int exynos_srom_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
-	return 0;
+	for_each_child_of_node(np, child) {
+		if (decode_sromc(srom, child)) {
+			dev_err(dev,
+				"Could not decode bank configuration for %s\n",
+				child->name);
+			error = true;
+		}
+	}
+
+	/*
+	 * If any bank failed to configure, we still provide suspend/resume,
+	 * but do not probe child devices
+	 */
+	if (error)
+		return 0;
+
+	return of_platform_populate(np, NULL, NULL, dev);
 }
 
 static int exynos_srom_remove(struct platform_device *pdev)
-- 
2.4.4




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