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