memory: Add support for Exynos SROM driver
This patch adds Exynos SROM controller driver which will handle
save restore of SROM registers during S2R.
Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
[p.fedin@samsung.com: tested on SMDK5410]
Tested-by: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Kukjin Kim <kgene@kernel.org>
[k.kozlowski: Minor COMPILE_TEST adjustments in Kconfig entries]
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
diff --git a/drivers/memory/samsung/exynos-srom.c b/drivers/memory/samsung/exynos-srom.c
new file mode 100644
index 0000000..68e073c
--- /dev/null
+++ b/drivers/memory/samsung/exynos-srom.c
@@ -0,0 +1,175 @@
+/*
+ * Copyright (c) 2015 Samsung Electronics Co., Ltd.
+ * http://www.samsung.com/
+ *
+ * EXYNOS - SROM Controller support
+ * Author: Pankaj Dubey <pankaj.dubey@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "exynos-srom.h"
+
+static const unsigned long exynos_srom_offsets[] = {
+ /* SROM side */
+ EXYNOS_SROM_BW,
+ EXYNOS_SROM_BC0,
+ EXYNOS_SROM_BC1,
+ EXYNOS_SROM_BC2,
+ EXYNOS_SROM_BC3,
+};
+
+/**
+ * struct exynos_srom_reg_dump: register dump of SROM Controller registers.
+ * @offset: srom register offset from the controller base address.
+ * @value: the value of register under the offset.
+ */
+struct exynos_srom_reg_dump {
+ u32 offset;
+ u32 value;
+};
+
+/**
+ * struct exynos_srom: platform data for exynos srom controller driver.
+ * @dev: platform device pointer
+ * @reg_base: srom base address
+ * @reg_offset: exynos_srom_reg_dump pointer to hold offset and its value.
+ */
+struct exynos_srom {
+ struct device *dev;
+ void __iomem *reg_base;
+ struct exynos_srom_reg_dump *reg_offset;
+};
+
+static struct exynos_srom_reg_dump *exynos_srom_alloc_reg_dump(
+ const unsigned long *rdump,
+ unsigned long nr_rdump)
+{
+ struct exynos_srom_reg_dump *rd;
+ unsigned int i;
+
+ rd = kcalloc(nr_rdump, sizeof(*rd), GFP_KERNEL);
+ if (!rd)
+ return NULL;
+
+ for (i = 0; i < nr_rdump; ++i)
+ rd[i].offset = rdump[i];
+
+ return rd;
+}
+
+static int exynos_srom_probe(struct platform_device *pdev)
+{
+ struct device_node *np;
+ struct exynos_srom *srom;
+ struct device *dev = &pdev->dev;
+
+ np = dev->of_node;
+ if (!np) {
+ dev_err(&pdev->dev, "could not find device info\n");
+ return -EINVAL;
+ }
+
+ srom = devm_kzalloc(&pdev->dev,
+ sizeof(struct exynos_srom), GFP_KERNEL);
+ if (!srom)
+ return -ENOMEM;
+
+ srom->dev = dev;
+ srom->reg_base = of_iomap(np, 0);
+ if (!srom->reg_base) {
+ dev_err(&pdev->dev, "iomap of exynos srom controller failed\n");
+ return -ENOMEM;
+ }
+
+ platform_set_drvdata(pdev, srom);
+
+ srom->reg_offset = exynos_srom_alloc_reg_dump(exynos_srom_offsets,
+ sizeof(exynos_srom_offsets));
+ if (!srom->reg_offset) {
+ iounmap(srom->reg_base);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int exynos_srom_remove(struct platform_device *pdev)
+{
+ struct exynos_srom *srom = platform_get_drvdata(pdev);
+
+ kfree(srom->reg_offset);
+ iounmap(srom->reg_base);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static void exynos_srom_save(void __iomem *base,
+ struct exynos_srom_reg_dump *rd,
+ unsigned int num_regs)
+{
+ for (; num_regs > 0; --num_regs, ++rd)
+ rd->value = readl(base + rd->offset);
+}
+
+static void exynos_srom_restore(void __iomem *base,
+ const struct exynos_srom_reg_dump *rd,
+ unsigned int num_regs)
+{
+ for (; num_regs > 0; --num_regs, ++rd)
+ writel(rd->value, base + rd->offset);
+}
+
+static int exynos_srom_suspend(struct device *dev)
+{
+ struct exynos_srom *srom = dev_get_drvdata(dev);
+
+ exynos_srom_save(srom->reg_base, srom->reg_offset,
+ ARRAY_SIZE(exynos_srom_offsets));
+ return 0;
+}
+
+static int exynos_srom_resume(struct device *dev)
+{
+ struct exynos_srom *srom = dev_get_drvdata(dev);
+
+ exynos_srom_restore(srom->reg_base, srom->reg_offset,
+ ARRAY_SIZE(exynos_srom_offsets));
+ return 0;
+}
+#endif
+
+static const struct of_device_id of_exynos_srom_ids[] = {
+ {
+ .compatible = "samsung,exynos4210-srom",
+ },
+ {},
+};
+MODULE_DEVICE_TABLE(of, of_exynos_srom_ids);
+
+static SIMPLE_DEV_PM_OPS(exynos_srom_pm_ops, exynos_srom_suspend, exynos_srom_resume);
+
+static struct platform_driver exynos_srom_driver = {
+ .probe = exynos_srom_probe,
+ .remove = exynos_srom_remove,
+ .driver = {
+ .name = "exynos-srom",
+ .of_match_table = of_exynos_srom_ids,
+ .pm = &exynos_srom_pm_ops,
+ },
+};
+module_platform_driver(exynos_srom_driver);
+
+MODULE_AUTHOR("Pankaj Dubey <pankaj.dubey@samsung.com>");
+MODULE_DESCRIPTION("Exynos SROM Controller Driver");
+MODULE_LICENSE("GPL");
