memory: samsung: exynos-srom: Add support for bank configuration

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@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

arch/arm/mach-exynos/Kconfig

@@ -18,7 +18,7 @@ menuconfig ARCH_EXYNOS
 	select COMMON_CLK_SAMSUNG
 	select EXYNOS_THERMAL
 	select EXYNOS_PMU
-	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

drivers/memory/samsung/Kconfig

@@ -8,6 +8,6 @@ if SAMSUNG_MC
 
 config EXYNOS_SROM
 	bool "Exynos SROM controller driver" if COMPILE_TEST
-	depends on (ARM && ARCH_EXYNOS && PM) || (COMPILE_TEST && HAS_IOMEM)
+	depends on (ARM && ARCH_EXYNOS) || (COMPILE_TEST && HAS_IOMEM)
 
 endif

drivers/memory/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 +68,50 @@ static struct exynos_srom_reg_dump *exynos_srom_alloc_reg_dump(
 	return rd;
 }
 
+static int exynos_srom_configure_bank(struct exynos_srom *srom,
+				      struct device_node *np)
+{
+	u32 bank, width, pmc = 0;
+	u32 timing[6];
+	u32 cs, bw;
+
+	if (of_property_read_u32(np, "reg", &bank))
+		return -EINVAL;
+	if (of_property_read_u32(np, "reg-io-width", &width))
+		width = 1;
+	if (of_property_read_bool(np, "samsung,srom-page-mode"))
+		pmc = 1 << EXYNOS_SROM_BCX__PMC__SHIFT;
+	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(pmc | (timing[0] << EXYNOS_SROM_BCX__TACP__SHIFT) |
+		    (timing[1] << EXYNOS_SROM_BCX__TCAH__SHIFT) |
+		    (timing[2] << EXYNOS_SROM_BCX__TCOH__SHIFT) |
+		    (timing[3] << EXYNOS_SROM_BCX__TACC__SHIFT) |
+		    (timing[4] << EXYNOS_SROM_BCX__TCOS__SHIFT) |
+		    (timing[5] << 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 bad_bank_config = false;
 
 	np = dev->of_node;
 	if (!np) {
@@ -100,7 +140,23 @@ static int exynos_srom_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
-	return 0;
+	for_each_child_of_node(np, child) {
+		if (exynos_srom_configure_bank(srom, child)) {
+			dev_err(dev,
+				"Could not decode bank configuration for %s\n",
+				child->name);
+			bad_bank_config = true;
+		}
+	}
+
+	/*
+	 * If any bank failed to configure, we still provide suspend/resume,
+	 * but do not probe child devices
+	 */
+	if (bad_bank_config)
+		return 0;
+
+	return of_platform_populate(np, NULL, NULL, dev);
 }
 
 static int exynos_srom_remove(struct platform_device *pdev)