drivers/mfd/altera-sysmgr.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  *  Copyright (C) 2018-2019, Intel Corporation.
0004  *  Copyright (C) 2012 Freescale Semiconductor, Inc.
0005  *  Copyright (C) 2012 Linaro Ltd.
0006  *
0007  *  Based on syscon driver.
0008  */
0009
0010 #include <linux/arm-smccc.h>
0011 #include <linux/err.h>
0012 #include <linux/io.h>
0013 #include <linux/mfd/altera-sysmgr.h>
0014 #include <linux/mfd/syscon.h>
0015 #include <linux/module.h>
0016 #include <linux/of.h>
0017 #include <linux/of_address.h>
0018 #include <linux/of_platform.h>
0019 #include <linux/regmap.h>
0020 #include <linux/slab.h>
0021
0022 /**
0023  * struct altr_sysmgr - Altera SOCFPGA System Manager
0024  * @regmap: the regmap used for System Manager accesses.
0025  */
0026 struct altr_sysmgr {
0027     struct regmap   *regmap;
0028 };
0029
0030 static struct platform_driver altr_sysmgr_driver;
0031
0032 /**
0033  * s10_protected_reg_write
0034  * Write to a protected SMC register.
0035  * @base: Base address of System Manager
0036  * @reg:  Address offset of register
0037  * @val:  Value to write
0038  * Return: INTEL_SIP_SMC_STATUS_OK (0) on success
0039  *     INTEL_SIP_SMC_REG_ERROR on error
0040  *     INTEL_SIP_SMC_RETURN_UNKNOWN_FUNCTION if not supported
0041  */
0042 static int s10_protected_reg_write(void *base,
0043                    unsigned int reg, unsigned int val)
0044 {
0045     struct arm_smccc_res result;
0046     unsigned long sysmgr_base = (unsigned long)base;
0047
0048     arm_smccc_smc(INTEL_SIP_SMC_REG_WRITE, sysmgr_base + reg,
0049               val, 0, 0, 0, 0, 0, &result);
0050
0051     return (int)result.a0;
0052 }
0053
0054 /**
0055  * s10_protected_reg_read
0056  * Read the status of a protected SMC register
0057  * @base: Base address of System Manager.
0058  * @reg:  Address of register
0059  * @val:  Value read.
0060  * Return: INTEL_SIP_SMC_STATUS_OK (0) on success
0061  *     INTEL_SIP_SMC_REG_ERROR on error
0062  *     INTEL_SIP_SMC_RETURN_UNKNOWN_FUNCTION if not supported
0063  */
0064 static int s10_protected_reg_read(void *base,
0065                   unsigned int reg, unsigned int *val)
0066 {
0067     struct arm_smccc_res result;
0068     unsigned long sysmgr_base = (unsigned long)base;
0069
0070     arm_smccc_smc(INTEL_SIP_SMC_REG_READ, sysmgr_base + reg,
0071               0, 0, 0, 0, 0, 0, &result);
0072
0073     *val = (unsigned int)result.a1;
0074
0075     return (int)result.a0;
0076 }
0077
0078 static struct regmap_config altr_sysmgr_regmap_cfg = {
0079     .name = "altr_sysmgr",
0080     .reg_bits = 32,
0081     .reg_stride = 4,
0082     .val_bits = 32,
0083     .fast_io = true,
0084     .use_single_read = true,
0085     .use_single_write = true,
0086 };
0087
0088 /**
0089  * altr_sysmgr_regmap_lookup_by_phandle
0090  * Find the sysmgr previous configured in probe() and return regmap property.
0091  * Return: regmap if found or error if not found.
0092  *
0093  * @np: Pointer to device's Device Tree node
0094  * @property: Device Tree property name which references the sysmgr
0095  */
0096 struct regmap *altr_sysmgr_regmap_lookup_by_phandle(struct device_node *np,
0097                             const char *property)
0098 {
0099     struct device *dev;
0100     struct altr_sysmgr *sysmgr;
0101     struct device_node *sysmgr_np;
0102
0103     if (property)
0104         sysmgr_np = of_parse_phandle(np, property, 0);
0105     else
0106         sysmgr_np = np;
0107
0108     if (!sysmgr_np)
0109         return ERR_PTR(-ENODEV);
0110
0111     dev = driver_find_device_by_of_node(&altr_sysmgr_driver.driver,
0112                         (void *)sysmgr_np);
0113     of_node_put(sysmgr_np);
0114     if (!dev)
0115         return ERR_PTR(-EPROBE_DEFER);
0116
0117     sysmgr = dev_get_drvdata(dev);
0118
0119     return sysmgr->regmap;
0120 }
0121 EXPORT_SYMBOL_GPL(altr_sysmgr_regmap_lookup_by_phandle);
0122
0123 static int sysmgr_probe(struct platform_device *pdev)
0124 {
0125     struct altr_sysmgr *sysmgr;
0126     struct regmap *regmap;
0127     struct resource *res;
0128     struct regmap_config sysmgr_config = altr_sysmgr_regmap_cfg;
0129     struct device *dev = &pdev->dev;
0130     struct device_node *np = dev->of_node;
0131     void __iomem *base;
0132
0133     sysmgr = devm_kzalloc(dev, sizeof(*sysmgr), GFP_KERNEL);
0134     if (!sysmgr)
0135         return -ENOMEM;
0136
0137     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
0138     if (!res)
0139         return -ENOENT;
0140
0141     sysmgr_config.max_register = resource_size(res) -
0142                      sysmgr_config.reg_stride;
0143     if (of_device_is_compatible(np, "altr,sys-mgr-s10")) {
0144         sysmgr_config.reg_read = s10_protected_reg_read;
0145         sysmgr_config.reg_write = s10_protected_reg_write;
0146
0147         /* Need physical address for SMCC call */
0148         regmap = devm_regmap_init(dev, NULL,
0149                       (void *)(uintptr_t)res->start,
0150                       &sysmgr_config);
0151     } else {
0152         base = devm_ioremap(dev, res->start, resource_size(res));
0153         if (!base)
0154             return -ENOMEM;
0155
0156         sysmgr_config.max_register = resource_size(res) - 4;
0157         regmap = devm_regmap_init_mmio(dev, base, &sysmgr_config);
0158     }
0159
0160     if (IS_ERR(regmap)) {
0161         pr_err("regmap init failed\n");
0162         return PTR_ERR(regmap);
0163     }
0164
0165     sysmgr->regmap = regmap;
0166
0167     platform_set_drvdata(pdev, sysmgr);
0168
0169     return 0;
0170 }
0171
0172 static const struct of_device_id altr_sysmgr_of_match[] = {
0173     { .compatible = "altr,sys-mgr" },
0174     { .compatible = "altr,sys-mgr-s10" },
0175     {},
0176 };
0177 MODULE_DEVICE_TABLE(of, altr_sysmgr_of_match);
0178
0179 static struct platform_driver altr_sysmgr_driver = {
0180     .probe =  sysmgr_probe,
0181     .driver = {
0182         .name = "altr,system_manager",
0183         .of_match_table = altr_sysmgr_of_match,
0184     },
0185 };
0186
0187 static int __init altr_sysmgr_init(void)
0188 {
0189     return platform_driver_register(&altr_sysmgr_driver);
0190 }
0191 core_initcall(altr_sysmgr_init);
0192
0193 static void __exit altr_sysmgr_exit(void)
0194 {
0195     platform_driver_unregister(&altr_sysmgr_driver);
0196 }
0197 module_exit(altr_sysmgr_exit);
0198
0199 MODULE_AUTHOR("Thor Thayer <>");
0200 MODULE_DESCRIPTION("SOCFPGA System Manager driver");
0201 MODULE_LICENSE("GPL v2");