diff options
Diffstat (limited to 'drivers/memory/samsung/exynos-srom.c')
| -rw-r--r-- | drivers/memory/samsung/exynos-srom.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/drivers/memory/samsung/exynos-srom.c b/drivers/memory/samsung/exynos-srom.c new file mode 100644 index 000000000000..68e073c1651c --- /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"); |