diff options
Diffstat (limited to 'drivers/mfd/altera-sysmgr.c')
| -rw-r--r-- | drivers/mfd/altera-sysmgr.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/drivers/mfd/altera-sysmgr.c b/drivers/mfd/altera-sysmgr.c new file mode 100644 index 000000000..5d3715a28 --- /dev/null +++ b/drivers/mfd/altera-sysmgr.c @@ -0,0 +1,201 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2018-2019, Intel Corporation. + * Copyright (C) 2012 Freescale Semiconductor, Inc. + * Copyright (C) 2012 Linaro Ltd. + * + * Based on syscon driver. + */ + +#include <linux/arm-smccc.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/mfd/altera-sysmgr.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_platform.h> +#include <linux/regmap.h> +#include <linux/slab.h> + +/** + * struct altr_sysmgr - Altera SOCFPGA System Manager + * @regmap: the regmap used for System Manager accesses. + */ +struct altr_sysmgr { + struct regmap *regmap; +}; + +static struct platform_driver altr_sysmgr_driver; + +/** + * s10_protected_reg_write + * Write to a protected SMC register. + * @base: Base address of System Manager + * @reg: Address offset of register + * @val: Value to write + * Return: INTEL_SIP_SMC_STATUS_OK (0) on success + * INTEL_SIP_SMC_REG_ERROR on error + * INTEL_SIP_SMC_RETURN_UNKNOWN_FUNCTION if not supported + */ +static int s10_protected_reg_write(void *base, + unsigned int reg, unsigned int val) +{ + struct arm_smccc_res result; + unsigned long sysmgr_base = (unsigned long)base; + + arm_smccc_smc(INTEL_SIP_SMC_REG_WRITE, sysmgr_base + reg, + val, 0, 0, 0, 0, 0, &result); + + return (int)result.a0; +} + +/** + * s10_protected_reg_read + * Read the status of a protected SMC register + * @base: Base address of System Manager. + * @reg: Address of register + * @val: Value read. + * Return: INTEL_SIP_SMC_STATUS_OK (0) on success + * INTEL_SIP_SMC_REG_ERROR on error + * INTEL_SIP_SMC_RETURN_UNKNOWN_FUNCTION if not supported + */ +static int s10_protected_reg_read(void *base, + unsigned int reg, unsigned int *val) +{ + struct arm_smccc_res result; + unsigned long sysmgr_base = (unsigned long)base; + + arm_smccc_smc(INTEL_SIP_SMC_REG_READ, sysmgr_base + reg, + 0, 0, 0, 0, 0, 0, &result); + + *val = (unsigned int)result.a1; + + return (int)result.a0; +} + +static struct regmap_config altr_sysmgr_regmap_cfg = { + .name = "altr_sysmgr", + .reg_bits = 32, + .reg_stride = 4, + .val_bits = 32, + .fast_io = true, + .use_single_read = true, + .use_single_write = true, +}; + +/** + * altr_sysmgr_regmap_lookup_by_phandle + * Find the sysmgr previous configured in probe() and return regmap property. + * Return: regmap if found or error if not found. + * + * @np: Pointer to device's Device Tree node + * @property: Device Tree property name which references the sysmgr + */ +struct regmap *altr_sysmgr_regmap_lookup_by_phandle(struct device_node *np, + const char *property) +{ + struct device *dev; + struct altr_sysmgr *sysmgr; + struct device_node *sysmgr_np; + + if (property) + sysmgr_np = of_parse_phandle(np, property, 0); + else + sysmgr_np = np; + + if (!sysmgr_np) + return ERR_PTR(-ENODEV); + + dev = driver_find_device_by_of_node(&altr_sysmgr_driver.driver, + (void *)sysmgr_np); + of_node_put(sysmgr_np); + if (!dev) + return ERR_PTR(-EPROBE_DEFER); + + sysmgr = dev_get_drvdata(dev); + + return sysmgr->regmap; +} +EXPORT_SYMBOL_GPL(altr_sysmgr_regmap_lookup_by_phandle); + +static int sysmgr_probe(struct platform_device *pdev) +{ + struct altr_sysmgr *sysmgr; + struct regmap *regmap; + struct resource *res; + struct regmap_config sysmgr_config = altr_sysmgr_regmap_cfg; + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + void __iomem *base; + + sysmgr = devm_kzalloc(dev, sizeof(*sysmgr), GFP_KERNEL); + if (!sysmgr) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENOENT; + + sysmgr_config.max_register = resource_size(res) - + sysmgr_config.reg_stride; + if (of_device_is_compatible(np, "altr,sys-mgr-s10")) { + sysmgr_config.reg_read = s10_protected_reg_read; + sysmgr_config.reg_write = s10_protected_reg_write; + + /* Need physical address for SMCC call */ + regmap = devm_regmap_init(dev, NULL, + (void *)(uintptr_t)res->start, + &sysmgr_config); + } else { + base = devm_ioremap(dev, res->start, resource_size(res)); + if (!base) + return -ENOMEM; + + sysmgr_config.max_register = resource_size(res) - 4; + regmap = devm_regmap_init_mmio(dev, base, &sysmgr_config); + } + + if (IS_ERR(regmap)) { + pr_err("regmap init failed\n"); + return PTR_ERR(regmap); + } + + sysmgr->regmap = regmap; + + platform_set_drvdata(pdev, sysmgr); + + return 0; +} + +static const struct of_device_id altr_sysmgr_of_match[] = { + { .compatible = "altr,sys-mgr" }, + { .compatible = "altr,sys-mgr-s10" }, + {}, +}; +MODULE_DEVICE_TABLE(of, altr_sysmgr_of_match); + +static struct platform_driver altr_sysmgr_driver = { + .probe = sysmgr_probe, + .driver = { + .name = "altr,system_manager", + .of_match_table = altr_sysmgr_of_match, + }, +}; + +static int __init altr_sysmgr_init(void) +{ + return platform_driver_register(&altr_sysmgr_driver); +} +core_initcall(altr_sysmgr_init); + +static void __exit altr_sysmgr_exit(void) +{ + platform_driver_unregister(&altr_sysmgr_driver); +} +module_exit(altr_sysmgr_exit); + +MODULE_AUTHOR("Thor Thayer <>"); +MODULE_DESCRIPTION("SOCFPGA System Manager driver"); +MODULE_LICENSE("GPL v2"); |