drivers/mfd/altera-sysmgr.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Copyright (C) 2018-2019, Intel Corporation.
   4  *  Copyright (C) 2012 Freescale Semiconductor, Inc.
   5  *  Copyright (C) 2012 Linaro Ltd.
   6  *
   7  *  Based on syscon driver.
   8  */
   9
  10 #include <linux/arm-smccc.h>
  11 #include <linux/err.h>
  12 #include <linux/io.h>
  13 #include <linux/mfd/altera-sysmgr.h>
  14 #include <linux/mfd/syscon.h>
  15 #include <linux/module.h>
  16 #include <linux/of.h>
  17 #include <linux/of_address.h>
  18 #include <linux/of_platform.h>
  19 #include <linux/regmap.h>
  20 #include <linux/slab.h>
  21
  22 /**
  23  * struct altr_sysmgr - Altera SOCFPGA System Manager
  24  * @regmap: the regmap used for System Manager accesses.
  25  */
  26 struct altr_sysmgr {
  27         struct regmap   *regmap;
  28 };
  29
  30 static struct platform_driver altr_sysmgr_driver;
  31
  32 /**
  33  * s10_protected_reg_write
  34  * Write to a protected SMC register.
  35  * @base: Base address of System Manager
  36  * @reg:  Address offset of register
  37  * @val:  Value to write
  38  * Return: INTEL_SIP_SMC_STATUS_OK (0) on success
  39  *         INTEL_SIP_SMC_REG_ERROR on error
  40  *         INTEL_SIP_SMC_RETURN_UNKNOWN_FUNCTION if not supported
  41  */
  42 static int s10_protected_reg_write(void *base,
  43                                    unsigned int reg, unsigned int val)
  44 {
  45         struct arm_smccc_res result;
  46         unsigned long sysmgr_base = (unsigned long)base;
  47
  48         arm_smccc_smc(INTEL_SIP_SMC_REG_WRITE, sysmgr_base + reg,
  49                       val, 0, 0, 0, 0, 0, &result);
  50
  51         return (int)result.a0;
  52 }
  53
  54 /**
  55  * s10_protected_reg_read
  56  * Read the status of a protected SMC register
  57  * @base: Base address of System Manager.
  58  * @reg:  Address of register
  59  * @val:  Value read.
  60  * Return: INTEL_SIP_SMC_STATUS_OK (0) on success
  61  *         INTEL_SIP_SMC_REG_ERROR on error
  62  *         INTEL_SIP_SMC_RETURN_UNKNOWN_FUNCTION if not supported
  63  */
  64 static int s10_protected_reg_read(void *base,
  65                                   unsigned int reg, unsigned int *val)
  66 {
  67         struct arm_smccc_res result;
  68         unsigned long sysmgr_base = (unsigned long)base;
  69
  70         arm_smccc_smc(INTEL_SIP_SMC_REG_READ, sysmgr_base + reg,
  71                       0, 0, 0, 0, 0, 0, &result);
  72
  73         *val = (unsigned int)result.a1;
  74
  75         return (int)result.a0;
  76 }
  77
  78 static struct regmap_config altr_sysmgr_regmap_cfg = {
  79         .name = "altr_sysmgr",
  80         .reg_bits = 32,
  81         .reg_stride = 4,
  82         .val_bits = 32,
  83         .fast_io = true,
  84         .use_single_read = true,
  85         .use_single_write = true,
  86 };
  87
  88 /**
  89  * altr_sysmgr_regmap_lookup_by_phandle
  90  * Find the sysmgr previous configured in probe() and return regmap property.
  91  * Return: regmap if found or error if not found.
  92  *
  93  * @np: Pointer to device's Device Tree node
  94  * @property: Device Tree property name which references the sysmgr
  95  */
  96 struct regmap *altr_sysmgr_regmap_lookup_by_phandle(struct device_node *np,
  97                                                     const char *property)
  98 {
  99         struct device *dev;
 100         struct altr_sysmgr *sysmgr;
 101         struct device_node *sysmgr_np;
 102
 103         if (property)
 104                 sysmgr_np = of_parse_phandle(np, property, 0);
 105         else
 106                 sysmgr_np = np;
 107
 108         if (!sysmgr_np)
 109                 return ERR_PTR(-ENODEV);
 110
 111         dev = driver_find_device_by_of_node(&altr_sysmgr_driver.driver,
 112                                             (void *)sysmgr_np);
 113         of_node_put(sysmgr_np);
 114         if (!dev)
 115                 return ERR_PTR(-EPROBE_DEFER);
 116
 117         sysmgr = dev_get_drvdata(dev);
 118
 119         return sysmgr->regmap;
 120 }
 121 EXPORT_SYMBOL_GPL(altr_sysmgr_regmap_lookup_by_phandle);
 122
 123 static int sysmgr_probe(struct platform_device *pdev)
 124 {
 125         struct altr_sysmgr *sysmgr;
 126         struct regmap *regmap;
 127         struct resource *res;
 128         struct regmap_config sysmgr_config = altr_sysmgr_regmap_cfg;
 129         struct device *dev = &pdev->dev;
 130         struct device_node *np = dev->of_node;
 131         void __iomem *base;
 132
 133         sysmgr = devm_kzalloc(dev, sizeof(*sysmgr), GFP_KERNEL);
 134         if (!sysmgr)
 135                 return -ENOMEM;
 136
 137         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 138         if (!res)
 139                 return -ENOENT;
 140
 141         sysmgr_config.max_register = resource_size(res) -
 142                                      sysmgr_config.reg_stride;
 143         if (of_device_is_compatible(np, "altr,sys-mgr-s10")) {
 144                 sysmgr_config.reg_read = s10_protected_reg_read;
 145                 sysmgr_config.reg_write = s10_protected_reg_write;
 146
 147                 /* Need physical address for SMCC call */
 148                 regmap = devm_regmap_init(dev, NULL,
 149                                           (void *)(uintptr_t)res->start,
 150                                           &sysmgr_config);
 151         } else {
 152                 base = devm_ioremap(dev, res->start, resource_size(res));
 153                 if (!base)
 154                         return -ENOMEM;
 155
 156                 sysmgr_config.max_register = resource_size(res) - 3;
 157                 regmap = devm_regmap_init_mmio(dev, base, &sysmgr_config);
 158         }
 159
 160         if (IS_ERR(regmap)) {
 161                 pr_err("regmap init failed\n");
 162                 return PTR_ERR(regmap);
 163         }
 164
 165         sysmgr->regmap = regmap;
 166
 167         platform_set_drvdata(pdev, sysmgr);
 168
 169         return 0;
 170 }
 171
 172 static const struct of_device_id altr_sysmgr_of_match[] = {
 173         { .compatible = "altr,sys-mgr" },
 174         { .compatible = "altr,sys-mgr-s10" },
 175         {},
 176 };
 177 MODULE_DEVICE_TABLE(of, altr_sysmgr_of_match);
 178
 179 static struct platform_driver altr_sysmgr_driver = {
 180         .probe =  sysmgr_probe,
 181         .driver = {
 182                 .name = "altr,system_manager",
 183                 .of_match_table = altr_sysmgr_of_match,
 184         },
 185 };
 186
 187 static int __init altr_sysmgr_init(void)
 188 {
 189         return platform_driver_register(&altr_sysmgr_driver);
 190 }
 191 core_initcall(altr_sysmgr_init);
 192
 193 static void __exit altr_sysmgr_exit(void)
 194 {
 195         platform_driver_unregister(&altr_sysmgr_driver);
 196 }
 197 module_exit(altr_sysmgr_exit);
 198
 199 MODULE_AUTHOR("Thor Thayer <>");
 200 MODULE_DESCRIPTION("SOCFPGA System Manager driver");
 201 MODULE_LICENSE("GPL v2");