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>

2 files changed, 59 insertions, 3 deletions

diff --git a/drivers/memory/samsung/Kconfig b/drivers/memory/samsung/Kconfig
index 64ab5dd9f626..9de12222061c 100644
--- a/drivers/memory/samsung/Kconfig
+++ b/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
diff --git a/drivers/memory/samsung/exynos-srom.c b/drivers/memory/samsung/exynos-srom.c
index 68e073c1651c..96756fb4d6bd 100644
--- a/drivers/memory/samsung/exynos-srom.c
+++ b/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)