diff options
Diffstat (limited to 'drivers/soc/samsung/exynos-pmu.c')
| -rw-r--r-- | drivers/soc/samsung/exynos-pmu.c | 235 |
1 files changed, 233 insertions, 2 deletions
diff --git a/drivers/soc/samsung/exynos-pmu.c b/drivers/soc/samsung/exynos-pmu.c index 250537d7cf..fd8b6ac066 100644 --- a/drivers/soc/samsung/exynos-pmu.c +++ b/drivers/soc/samsung/exynos-pmu.c @@ -5,6 +5,7 @@ // // Exynos - CPU PMU(Power Management Unit) support +#include <linux/arm-smccc.h> #include <linux/of.h> #include <linux/of_address.h> #include <linux/mfd/core.h> @@ -12,19 +13,134 @@ #include <linux/of_platform.h> #include <linux/platform_device.h> #include <linux/delay.h> +#include <linux/regmap.h> #include <linux/soc/samsung/exynos-regs-pmu.h> #include <linux/soc/samsung/exynos-pmu.h> #include "exynos-pmu.h" +#define PMUALIVE_MASK GENMASK(13, 0) +#define TENSOR_SET_BITS (BIT(15) | BIT(14)) +#define TENSOR_CLR_BITS BIT(15) +#define TENSOR_SMC_PMU_SEC_REG 0x82000504 +#define TENSOR_PMUREG_READ 0 +#define TENSOR_PMUREG_WRITE 1 +#define TENSOR_PMUREG_RMW 2 + struct exynos_pmu_context { struct device *dev; const struct exynos_pmu_data *pmu_data; + struct regmap *pmureg; }; void __iomem *pmu_base_addr; static struct exynos_pmu_context *pmu_context; +/* forward declaration */ +static struct platform_driver exynos_pmu_driver; + +/* + * Tensor SoCs are configured so that PMU_ALIVE registers can only be written + * from EL3, but are still read accessible. As Linux needs to write some of + * these registers, the following functions are provided and exposed via + * regmap. + * + * Note: This SMC interface is known to be implemented on gs101 and derivative + * SoCs. + */ + +/* Write to a protected PMU register. */ +static int tensor_sec_reg_write(void *context, unsigned int reg, + unsigned int val) +{ + struct arm_smccc_res res; + unsigned long pmu_base = (unsigned long)context; + + arm_smccc_smc(TENSOR_SMC_PMU_SEC_REG, pmu_base + reg, + TENSOR_PMUREG_WRITE, val, 0, 0, 0, 0, &res); + + /* returns -EINVAL if access isn't allowed or 0 */ + if (res.a0) + pr_warn("%s(): SMC failed: %d\n", __func__, (int)res.a0); + + return (int)res.a0; +} + +/* Read/Modify/Write a protected PMU register. */ +static int tensor_sec_reg_rmw(void *context, unsigned int reg, + unsigned int mask, unsigned int val) +{ + struct arm_smccc_res res; + unsigned long pmu_base = (unsigned long)context; + + arm_smccc_smc(TENSOR_SMC_PMU_SEC_REG, pmu_base + reg, + TENSOR_PMUREG_RMW, mask, val, 0, 0, 0, &res); + + /* returns -EINVAL if access isn't allowed or 0 */ + if (res.a0) + pr_warn("%s(): SMC failed: %d\n", __func__, (int)res.a0); + + return (int)res.a0; +} + +/* + * Read a protected PMU register. All PMU registers can be read by Linux. + * Note: The SMC read register is not used, as only registers that can be + * written are readable via SMC. + */ +static int tensor_sec_reg_read(void *context, unsigned int reg, + unsigned int *val) +{ + *val = pmu_raw_readl(reg); + return 0; +} + +/* + * For SoCs that have set/clear bit hardware this function can be used when + * the PMU register will be accessed by multiple masters. + * + * For example, to set bits 13:8 in PMU reg offset 0x3e80 + * tensor_set_bits_atomic(ctx, 0x3e80, 0x3f00, 0x3f00); + * + * Set bit 8, and clear bits 13:9 PMU reg offset 0x3e80 + * tensor_set_bits_atomic(0x3e80, 0x100, 0x3f00); + */ +static int tensor_set_bits_atomic(void *ctx, unsigned int offset, u32 val, + u32 mask) +{ + int ret; + unsigned int i; + + for (i = 0; i < 32; i++) { + if (!(mask & BIT(i))) + continue; + + offset &= ~TENSOR_SET_BITS; + + if (val & BIT(i)) + offset |= TENSOR_SET_BITS; + else + offset |= TENSOR_CLR_BITS; + + ret = tensor_sec_reg_write(ctx, offset, i); + if (ret) + return ret; + } + return ret; +} + +static int tensor_sec_update_bits(void *ctx, unsigned int reg, + unsigned int mask, unsigned int val) +{ + /* + * Use atomic operations for PMU_ALIVE registers (offset 0~0x3FFF) + * as the target registers can be accessed by multiple masters. + */ + if (reg > PMUALIVE_MASK) + return tensor_sec_reg_rmw(ctx, reg, mask, val); + + return tensor_set_bits_atomic(ctx, reg, val, mask); +} void pmu_raw_writel(u32 val, u32 offset) { @@ -75,11 +191,41 @@ void exynos_sys_powerdown_conf(enum sys_powerdown mode) #define exynos_pmu_data_arm_ptr(data) NULL #endif +static const struct regmap_config regmap_smccfg = { + .name = "pmu_regs", + .reg_bits = 32, + .reg_stride = 4, + .val_bits = 32, + .fast_io = true, + .use_single_read = true, + .use_single_write = true, + .reg_read = tensor_sec_reg_read, + .reg_write = tensor_sec_reg_write, + .reg_update_bits = tensor_sec_update_bits, +}; + +static const struct regmap_config regmap_mmiocfg = { + .name = "pmu_regs", + .reg_bits = 32, + .reg_stride = 4, + .val_bits = 32, + .fast_io = true, + .use_single_read = true, + .use_single_write = true, +}; + +static const struct exynos_pmu_data gs101_pmu_data = { + .pmu_secure = true +}; + /* * PMU platform driver and devicetree bindings. */ static const struct of_device_id exynos_pmu_of_device_ids[] = { { + .compatible = "google,gs101-pmu", + .data = &gs101_pmu_data, + }, { .compatible = "samsung,exynos3250-pmu", .data = exynos_pmu_data_arm_ptr(exynos3250_pmu_data), }, { @@ -113,19 +259,75 @@ static const struct mfd_cell exynos_pmu_devs[] = { { .name = "exynos-clkout", }, }; +/** + * exynos_get_pmu_regmap() - Obtain pmureg regmap + * + * Find the pmureg regmap previously configured in probe() and return regmap + * pointer. + * + * Return: A pointer to regmap if found or ERR_PTR error value. + */ struct regmap *exynos_get_pmu_regmap(void) { struct device_node *np = of_find_matching_node(NULL, exynos_pmu_of_device_ids); if (np) - return syscon_node_to_regmap(np); + return exynos_get_pmu_regmap_by_phandle(np, NULL); return ERR_PTR(-ENODEV); } EXPORT_SYMBOL_GPL(exynos_get_pmu_regmap); +/** + * exynos_get_pmu_regmap_by_phandle() - Obtain pmureg regmap via phandle + * @np: Device node holding PMU phandle property + * @propname: Name of property holding phandle value + * + * Find the pmureg regmap previously configured in probe() and return regmap + * pointer. + * + * Return: A pointer to regmap if found or ERR_PTR error value. + */ +struct regmap *exynos_get_pmu_regmap_by_phandle(struct device_node *np, + const char *propname) +{ + struct exynos_pmu_context *ctx; + struct device_node *pmu_np; + struct device *dev; + + if (propname) + pmu_np = of_parse_phandle(np, propname, 0); + else + pmu_np = np; + + if (!pmu_np) + return ERR_PTR(-ENODEV); + + /* + * Determine if exynos-pmu device has probed and therefore regmap + * has been created and can be returned to the caller. Otherwise we + * return -EPROBE_DEFER. + */ + dev = driver_find_device_by_of_node(&exynos_pmu_driver.driver, + (void *)pmu_np); + + if (propname) + of_node_put(pmu_np); + + if (!dev) + return ERR_PTR(-EPROBE_DEFER); + + ctx = dev_get_drvdata(dev); + + return ctx->pmureg; +} +EXPORT_SYMBOL_GPL(exynos_get_pmu_regmap_by_phandle); + static int exynos_pmu_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; + struct regmap_config pmu_regmcfg; + struct regmap *regmap; + struct resource *res; int ret; pmu_base_addr = devm_platform_ioremap_resource(pdev, 0); @@ -137,9 +339,38 @@ static int exynos_pmu_probe(struct platform_device *pdev) GFP_KERNEL); if (!pmu_context) return -ENOMEM; - pmu_context->dev = dev; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + pmu_context->pmu_data = of_device_get_match_data(dev); + /* For SoCs that secure PMU register writes use custom regmap */ + if (pmu_context->pmu_data && pmu_context->pmu_data->pmu_secure) { + pmu_regmcfg = regmap_smccfg; + pmu_regmcfg.max_register = resource_size(res) - + pmu_regmcfg.reg_stride; + /* Need physical address for SMC call */ + regmap = devm_regmap_init(dev, NULL, + (void *)(uintptr_t)res->start, + &pmu_regmcfg); + } else { + /* All other SoCs use a MMIO regmap */ + pmu_regmcfg = regmap_mmiocfg; + pmu_regmcfg.max_register = resource_size(res) - + pmu_regmcfg.reg_stride; + regmap = devm_regmap_init_mmio(dev, pmu_base_addr, + &pmu_regmcfg); + } + + if (IS_ERR(regmap)) + return dev_err_probe(&pdev->dev, PTR_ERR(regmap), + "regmap init failed\n"); + + pmu_context->pmureg = regmap; + pmu_context->dev = dev; + if (pmu_context->pmu_data && pmu_context->pmu_data->pmu_init) pmu_context->pmu_data->pmu_init(); |