This patch adds a small regulator driver to manage the voltage regulator inside the ST flash subsystem found on stih407 based silicon, and is used for configuring the eMMC, NAND and SPI voltages. Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx> Signed-off-by: Peter Griffin <peter.griffin@xxxxxxxxxx> --- drivers/regulator/Kconfig | 7 ++ drivers/regulator/Makefile | 2 +- drivers/regulator/st-flashss.c | 274 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 282 insertions(+), 1 deletion(-) create mode 100644 drivers/regulator/st-flashss.c diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig index c77dc08..ddf2bcd 100644 --- a/drivers/regulator/Kconfig +++ b/drivers/regulator/Kconfig @@ -843,5 +843,12 @@ config REGULATOR_WM8994 This driver provides support for the voltage regulators on the WM8994 CODEC. +config REGULATOR_ST_FLASHSS + tristate "STMicroelectronics FlashSS regulator" + depends on ARCH_STI && OF + help + This driver provides support for the voltage regulators available + inside the FlashSS of STiH407/STiH410 SoC's. + endif diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile index 61bfbb9..10be29b 100644 --- a/drivers/regulator/Makefile +++ b/drivers/regulator/Makefile @@ -108,6 +108,6 @@ obj-$(CONFIG_REGULATOR_WM831X) += wm831x-ldo.o obj-$(CONFIG_REGULATOR_WM8350) += wm8350-regulator.o obj-$(CONFIG_REGULATOR_WM8400) += wm8400-regulator.o obj-$(CONFIG_REGULATOR_WM8994) += wm8994-regulator.o - +obj-$(CONFIG_REGULATOR_ST_FLASHSS) += st-flashss.o ccflags-$(CONFIG_REGULATOR_DEBUG) += -DDEBUG diff --git a/drivers/regulator/st-flashss.c b/drivers/regulator/st-flashss.c new file mode 100644 index 0000000..9c0e011 --- /dev/null +++ b/drivers/regulator/st-flashss.c @@ -0,0 +1,274 @@ +/* + * ST regulator driver for flashSS vsense + * + * This is a small driver to manage the voltage regulator inside the ST flash + * sub-system that is used for configuring MMC, NAND, SPI voltages. + * + * Copyright(C) 2015 STMicroelectronics Ltd + * Author: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ +#include <linux/module.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/regulator/driver.h> +#include <linux/regulator/machine.h> +#include <linux/regulator/of_regulator.h> + +/* FlashSS voltage VSENSE TOP CONFIG register defines */ +#define TOP_VSENSE_CONFIG_REG_PSW_EMMC BIT(0) +#define TOP_VSENSE_CONFIG_ENB_REG_PSW_EMMC BIT(1) +#define TOP_VSENSE_CONFIG_REG_PSW_NAND BIT(8) +#define TOP_VSENSE_CONFIG_ENB_REG_PSW_NAND BIT(9) +#define TOP_VSENSE_CONFIG_REG_PSW_SPI BIT(16) +#define TOP_VSENSE_CONFIG_ENB_REG_PSW_SPI BIT(17) +#define TOP_VSENSE_CONFIG_LATCHED_PSW_EMMC BIT(24) +#define TOP_VSENSE_CONFIG_LATCHED_PSW_NAND BIT(25) +#define TOP_VSENSE_CONFIG_LATCHED_PSW_SPI BIT(26) + +struct st_vsense { + char *name; + struct device *dev; + u8 n_voltages; /* number of supported voltages */ + void __iomem *ioaddr; /* TOP config base address */ + unsigned int en_psw_mask; /* Mask/enable vdd for each device */ + unsigned int psw_mask; /* Power sel mask for VDD */ + unsigned int latched_mask; /* Latched mask for VDD */ +}; + +static const unsigned int st_type_voltages[] = { + 1800000, + 3300000, +}; + +const struct st_vsense st_vsense_data[] = { + { + .en_psw_mask = TOP_VSENSE_CONFIG_ENB_REG_PSW_EMMC, + .psw_mask = TOP_VSENSE_CONFIG_REG_PSW_EMMC, + .latched_mask = TOP_VSENSE_CONFIG_LATCHED_PSW_EMMC, + }, { + .en_psw_mask = TOP_VSENSE_CONFIG_ENB_REG_PSW_NAND, + .psw_mask = TOP_VSENSE_CONFIG_REG_PSW_NAND, + .latched_mask = TOP_VSENSE_CONFIG_LATCHED_PSW_NAND, + }, { + .en_psw_mask = TOP_VSENSE_CONFIG_ENB_REG_PSW_SPI, + .psw_mask = TOP_VSENSE_CONFIG_REG_PSW_SPI, + .latched_mask = TOP_VSENSE_CONFIG_LATCHED_PSW_SPI, + }, +}; + +/* Get the value of Sensed-PSW of eMMC/NAND/SPI Pads */ +static int st_get_voltage_sel(struct regulator_dev *dev) +{ + struct st_vsense *vsense = rdev_get_drvdata(dev); + void __iomem *ioaddr = vsense->ioaddr; + int sel = 0; + u32 value = readl_relaxed(ioaddr); + + if (value & vsense->latched_mask) + sel = 1; + + dev_dbg(vsense->dev, "%s, selection %d (0x%08x)\n", vsense->name, sel, + readl_relaxed(ioaddr)); + + return sel; +} + +static int st_set_voltage_sel(struct regulator_dev *dev, unsigned int selector) +{ + struct st_vsense *vsense = rdev_get_drvdata(dev); + void __iomem *ioaddr = vsense->ioaddr; + unsigned int value = readl_relaxed(ioaddr); + unsigned int voltage; + + voltage = st_type_voltages[selector]; + + value |= vsense->en_psw_mask; + if (voltage == 3300000) + value |= vsense->psw_mask; + else + value &= ~vsense->psw_mask; + + writel_relaxed(value, ioaddr); + + dev_dbg(vsense->dev, "%s, required voltage %d (vsense_conf 0x%08x)\n", + vsense->name, voltage, + readl_relaxed(ioaddr)); + + return 0; +} + +static struct regulator_ops st_ops = { + .get_voltage_sel = st_get_voltage_sel, + .set_voltage_sel = st_set_voltage_sel, + .list_voltage = regulator_list_voltage_table, +}; + +static const struct of_device_id of_st_match_tbl[] = { + {.compatible = "st,vqmmc", .data = &st_vsense_data[0]}, + {.compatible = "st,vnand", .data = &st_vsense_data[1]}, + {.compatible = "st,vspi", .data = &st_vsense_data[2]}, + { /* end */ } +}; + +static void st_get_satinize_powerup_voltage(struct st_vsense *vsense) +{ + void __iomem *ioaddr = vsense->ioaddr; + u32 value = readl_relaxed(ioaddr); + + dev_dbg(vsense->dev, "Initial start-up value: (0x%08x)\n", value); + + /* Sanitize voltage values forcing what is provided from start-up */ + if (value & TOP_VSENSE_CONFIG_LATCHED_PSW_EMMC) + value |= TOP_VSENSE_CONFIG_REG_PSW_EMMC; + else + value &= ~TOP_VSENSE_CONFIG_REG_PSW_EMMC; + + if (value & TOP_VSENSE_CONFIG_LATCHED_PSW_NAND) + value |= TOP_VSENSE_CONFIG_REG_PSW_NAND; + else + value &= ~TOP_VSENSE_CONFIG_REG_PSW_NAND; + + if (value & TOP_VSENSE_CONFIG_LATCHED_PSW_SPI) + value |= TOP_VSENSE_CONFIG_REG_PSW_SPI; + else + value &= ~TOP_VSENSE_CONFIG_REG_PSW_SPI; + + writel_relaxed(value, ioaddr); + + dev_dbg(vsense->dev, "Sanitized value: (0x%08x)\n", value); +} + +static int st_vsense_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct st_vsense *vsense; + const struct of_device_id *device; + struct resource *res; + struct regulator_desc *rdesc; + struct regulator_dev *rdev; + struct regulator_config config = { }; + + vsense = devm_kzalloc(dev, sizeof(*vsense), GFP_KERNEL); + if (!vsense) + return -ENOMEM; + + vsense->dev = dev; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + vsense->ioaddr = devm_ioremap_resource(dev, res); + if (IS_ERR(vsense->ioaddr)) + return PTR_ERR(vsense->ioaddr); + + rdesc = devm_kzalloc(dev, sizeof(*rdesc), GFP_KERNEL); + if (!rdesc) + return -ENOMEM; + + device = of_match_device(of_st_match_tbl, &pdev->dev); + if (!device) + return -ENODEV; + + if (device->data) { + const struct st_vsense *data = device->data; + + vsense->en_psw_mask = data->en_psw_mask; + vsense->psw_mask = data->psw_mask; + vsense->latched_mask = data->latched_mask; + } else + return -ENODEV; + + if (of_property_read_string(np, "regulator-name", + (const char **)&vsense->name)) + return -EINVAL; + + memset(rdesc, 0, sizeof(*rdesc)); + rdesc->name = vsense->name; + rdesc->ops = &st_ops; + rdesc->type = REGULATOR_VOLTAGE; + rdesc->owner = THIS_MODULE; + rdesc->n_voltages = ARRAY_SIZE(st_type_voltages); + rdesc->volt_table = st_type_voltages; + config.dev = &pdev->dev; + config.driver_data = vsense; + config.of_node = np; + + config.init_data = of_get_regulator_init_data(&pdev->dev, np, rdesc); + if (!config.init_data) { + dev_err(dev, "Failed to parse regulator init data\n"); + return -ENOMEM; + } + + /* register regulator */ + rdev = regulator_register(rdesc, &config); + if (IS_ERR(rdev)) { + dev_err(dev, "failed to register %s\n", rdesc->name); + return PTR_ERR(rdev); + } + + platform_set_drvdata(pdev, rdev); + + dev_info(dev, "%s vsense voltage regulator registered\n", rdesc->name); + st_get_satinize_powerup_voltage(vsense); + + return 0; +} + +static int st_vsense_remove(struct platform_device *pdev) +{ + struct regulator_dev *rdev = platform_get_drvdata(pdev); + + regulator_unregister(rdev); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int st_vsense_resume(struct device *dev) +{ + struct regulator_dev *rdev = dev_get_drvdata(dev); + struct st_vsense *vsense = rdev_get_drvdata(rdev); + + st_get_satinize_powerup_voltage(vsense); + + return 0; +} +#endif + +static const struct dev_pm_ops st_vsense_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(NULL, st_vsense_resume) +}; + +static struct platform_driver st_vsense_driver = { + .driver = { + .name = "st-vsense", + .of_match_table = of_st_match_tbl, + .pm = &st_vsense_pm_ops, + }, + .probe = st_vsense_probe, + .remove = st_vsense_remove, +}; + +static int __init st_vsense_init(void) +{ + return platform_driver_register(&st_vsense_driver); +} + +subsys_initcall(st_vsense_init); + +static void __exit st_vsense_cleanup(void) +{ + platform_driver_unregister(&st_vsense_driver); +} + +module_exit(st_vsense_cleanup); + +MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>"); +MODULE_DESCRIPTION("ST voltage regulator driver for vsense flashSS"); +MODULE_LICENSE("GPL v2"); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html