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  * @base  : the base address for the System Manager
  26  */
  27 struct altr_sysmgr {
  28         struct regmap   *regmap;
  29         resource_size_t *base;
  30 };
  31
  32 static struct platform_driver altr_sysmgr_driver;
  33
  34 /**
  35  * s10_protected_reg_write
  36  * Write to a protected SMC register.
  37  * @base: Base address of System Manager
  38  * @reg:  Address offset of register
  39  * @val:  Value to write
  40  * Return: INTEL_SIP_SMC_STATUS_OK (0) on success
  41  *         INTEL_SIP_SMC_REG_ERROR on error
  42  *         INTEL_SIP_SMC_RETURN_UNKNOWN_FUNCTION if not supported
  43  */
  44 static int s10_protected_reg_write(void *base,
  45                                    unsigned int reg, unsigned int val)
  46 {
  47         struct arm_smccc_res result;
  48         unsigned long sysmgr_base = (unsigned long)base;
  49
  50         arm_smccc_smc(INTEL_SIP_SMC_REG_WRITE, sysmgr_base + reg,
  51                       val, 0, 0, 0, 0, 0, &result);
  52
  53         return (int)result.a0;
  54 }
  55
  56 /**
  57  * s10_protected_reg_read
  58  * Read the status of a protected SMC register
  59  * @base: Base address of System Manager.
  60  * @reg:  Address of register
  61  * @val:  Value read.
  62  * Return: INTEL_SIP_SMC_STATUS_OK (0) on success
  63  *         INTEL_SIP_SMC_REG_ERROR on error
  64  *         INTEL_SIP_SMC_RETURN_UNKNOWN_FUNCTION if not supported
  65  */
  66 static int s10_protected_reg_read(void *base,
  67                                   unsigned int reg, unsigned int *val)
  68 {
  69         struct arm_smccc_res result;
  70         unsigned long sysmgr_base = (unsigned long)base;
  71
  72         arm_smccc_smc(INTEL_SIP_SMC_REG_READ, sysmgr_base + reg,
  73                       0, 0, 0, 0, 0, 0, &result);
  74
  75         *val = (unsigned int)result.a1;
  76
  77         return (int)result.a0;
  78 }
  79
  80 static struct regmap_config altr_sysmgr_regmap_cfg = {
  81         .name = "altr_sysmgr",
  82         .reg_bits = 32,
  83         .reg_stride = 4,
  84         .val_bits = 32,
  85         .fast_io = true,
  86         .use_single_read = true,
  87         .use_single_write = true,
  88 };
  89
  90 /**
  91  * altr_sysmgr_regmap_lookup_by_phandle
  92  * Find the sysmgr previous configured in probe() and return regmap property.
  93  * Return: regmap if found or error if not found.
  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         of_node_put(sysmgr_np);
 113         if (!dev)
 114                 return ERR_PTR(-EPROBE_DEFER);
 115
 116         sysmgr = dev_get_drvdata(dev);
 117
 118         return sysmgr->regmap;
 119 }
 120 EXPORT_SYMBOL_GPL(altr_sysmgr_regmap_lookup_by_phandle);
 121
 122 static int sysmgr_probe(struct platform_device *pdev)
 123 {
 124         struct altr_sysmgr *sysmgr;
 125         struct regmap *regmap;
 126         struct resource *res;
 127         struct regmap_config sysmgr_config = altr_sysmgr_regmap_cfg;
 128         struct device *dev = &pdev->dev;
 129         struct device_node *np = dev->of_node;
 130
 131         sysmgr = devm_kzalloc(dev, sizeof(*sysmgr), GFP_KERNEL);
 132         if (!sysmgr)
 133                 return -ENOMEM;
 134
 135         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 136         if (!res)
 137                 return -ENOENT;
 138
 139         sysmgr_config.max_register = resource_size(res) -
 140                                      sysmgr_config.reg_stride;
 141         if (of_device_is_compatible(np, "altr,sys-mgr-s10")) {
 142                 /* Need physical address for SMCC call */
 143                 sysmgr->base = (resource_size_t *)res->start;
 144                 sysmgr_config.reg_read = s10_protected_reg_read;
 145                 sysmgr_config.reg_write = s10_protected_reg_write;
 146
 147                 regmap = devm_regmap_init(dev, NULL, sysmgr->base,
 148                                           &sysmgr_config);
 149         } else {
 150                 sysmgr->base = devm_ioremap(dev, res->start,
 151                                             resource_size(res));
 152                 if (!sysmgr->base)
 153                         return -ENOMEM;
 154
 155                 sysmgr_config.max_register = res->end - res->start - 3;
 156                 regmap = devm_regmap_init_mmio(dev, sysmgr->base,
 157                                                &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");