drivers/remoteproc/st_remoteproc.c

   1 /*
   2  * ST's Remote Processor Control Driver
   3  *
   4  * Copyright (C) 2015 STMicroelectronics - All Rights Reserved
   5  *
   6  * Author: Ludovic Barre <ludovic.barre@st.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/clk.h>
  14 #include <linux/dma-mapping.h>
  15 #include <linux/err.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/kernel.h>
  18 #include <linux/mfd/syscon.h>
  19 #include <linux/module.h>
  20 #include <linux/of.h>
  21 #include <linux/of_device.h>
  22 #include <linux/of_reserved_mem.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/regmap.h>
  25 #include <linux/remoteproc.h>
  26 #include <linux/reset.h>
  27
  28 struct st_rproc_config {
  29         bool                    sw_reset;
  30         bool                    pwr_reset;
  31         unsigned long           bootaddr_mask;
  32 };
  33
  34 struct st_rproc {
  35         struct st_rproc_config  *config;
  36         struct reset_control    *sw_reset;
  37         struct reset_control    *pwr_reset;
  38         struct clk              *clk;
  39         u32                     clk_rate;
  40         struct regmap           *boot_base;
  41         u32                     boot_offset;
  42 };
  43
  44 static int st_rproc_start(struct rproc *rproc)
  45 {
  46         struct st_rproc *ddata = rproc->priv;
  47         int err;
  48
  49         regmap_update_bits(ddata->boot_base, ddata->boot_offset,
  50                            ddata->config->bootaddr_mask, rproc->bootaddr);
  51
  52         err = clk_enable(ddata->clk);
  53         if (err) {
  54                 dev_err(&rproc->dev, "Failed to enable clock\n");
  55                 return err;
  56         }
  57
  58         if (ddata->config->sw_reset) {
  59                 err = reset_control_deassert(ddata->sw_reset);
  60                 if (err) {
  61                         dev_err(&rproc->dev, "Failed to deassert S/W Reset\n");
  62                         goto sw_reset_fail;
  63                 }
  64         }
  65
  66         if (ddata->config->pwr_reset) {
  67                 err = reset_control_deassert(ddata->pwr_reset);
  68                 if (err) {
  69                         dev_err(&rproc->dev, "Failed to deassert Power Reset\n");
  70                         goto pwr_reset_fail;
  71                 }
  72         }
  73
  74         dev_info(&rproc->dev, "Started from 0x%x\n", rproc->bootaddr);
  75
  76         return 0;
  77
  78
  79 pwr_reset_fail:
  80         if (ddata->config->pwr_reset)
  81                 reset_control_assert(ddata->sw_reset);
  82 sw_reset_fail:
  83         clk_disable(ddata->clk);
  84
  85         return err;
  86 }
  87
  88 static int st_rproc_stop(struct rproc *rproc)
  89 {
  90         struct st_rproc *ddata = rproc->priv;
  91         int sw_err = 0, pwr_err = 0;
  92
  93         if (ddata->config->sw_reset) {
  94                 sw_err = reset_control_assert(ddata->sw_reset);
  95                 if (sw_err)
  96                         dev_err(&rproc->dev, "Failed to assert S/W Reset\n");
  97         }
  98
  99         if (ddata->config->pwr_reset) {
 100                 pwr_err = reset_control_assert(ddata->pwr_reset);
 101                 if (pwr_err)
 102                         dev_err(&rproc->dev, "Failed to assert Power Reset\n");
 103         }
 104
 105         clk_disable(ddata->clk);
 106
 107         return sw_err ?: pwr_err;
 108 }
 109
 110 static struct rproc_ops st_rproc_ops = {
 111         .start          = st_rproc_start,
 112         .stop           = st_rproc_stop,
 113 };
 114
 115 /*
 116  * Fetch state of the processor: 0 is off, 1 is on.
 117  */
 118 static int st_rproc_state(struct platform_device *pdev)
 119 {
 120         struct rproc *rproc = platform_get_drvdata(pdev);
 121         struct st_rproc *ddata = rproc->priv;
 122         int reset_sw = 0, reset_pwr = 0;
 123
 124         if (ddata->config->sw_reset)
 125                 reset_sw = reset_control_status(ddata->sw_reset);
 126
 127         if (ddata->config->pwr_reset)
 128                 reset_pwr = reset_control_status(ddata->pwr_reset);
 129
 130         if (reset_sw < 0 || reset_pwr < 0)
 131                 return -EINVAL;
 132
 133         return !reset_sw && !reset_pwr;
 134 }
 135
 136 static const struct st_rproc_config st40_rproc_cfg = {
 137         .sw_reset = true,
 138         .pwr_reset = true,
 139         .bootaddr_mask = GENMASK(28, 1),
 140 };
 141
 142 static const struct st_rproc_config st231_rproc_cfg = {
 143         .sw_reset = true,
 144         .pwr_reset = false,
 145         .bootaddr_mask = GENMASK(31, 6),
 146 };
 147
 148 static const struct of_device_id st_rproc_match[] = {
 149         { .compatible = "st,st40-rproc", .data = &st40_rproc_cfg },
 150         { .compatible = "st,st231-rproc", .data = &st231_rproc_cfg },
 151         {},
 152 };
 153 MODULE_DEVICE_TABLE(of, st_rproc_match);
 154
 155 static int st_rproc_parse_dt(struct platform_device *pdev)
 156 {
 157         struct device *dev = &pdev->dev;
 158         struct rproc *rproc = platform_get_drvdata(pdev);
 159         struct st_rproc *ddata = rproc->priv;
 160         struct device_node *np = dev->of_node;
 161         int err;
 162
 163         if (ddata->config->sw_reset) {
 164                 ddata->sw_reset = devm_reset_control_get(dev, "sw_reset");
 165                 if (IS_ERR(ddata->sw_reset)) {
 166                         dev_err(dev, "Failed to get S/W Reset\n");
 167                         return PTR_ERR(ddata->sw_reset);
 168                 }
 169         }
 170
 171         if (ddata->config->pwr_reset) {
 172                 ddata->pwr_reset = devm_reset_control_get(dev, "pwr_reset");
 173                 if (IS_ERR(ddata->pwr_reset)) {
 174                         dev_err(dev, "Failed to get Power Reset\n");
 175                         return PTR_ERR(ddata->pwr_reset);
 176                 }
 177         }
 178
 179         ddata->clk = devm_clk_get(dev, NULL);
 180         if (IS_ERR(ddata->clk)) {
 181                 dev_err(dev, "Failed to get clock\n");
 182                 return PTR_ERR(ddata->clk);
 183         }
 184
 185         err = of_property_read_u32(np, "clock-frequency", &ddata->clk_rate);
 186         if (err) {
 187                 dev_err(dev, "failed to get clock frequency\n");
 188                 return err;
 189         }
 190
 191         ddata->boot_base = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
 192         if (IS_ERR(ddata->boot_base)) {
 193                 dev_err(dev, "Boot base not found\n");
 194                 return PTR_ERR(ddata->boot_base);
 195         }
 196
 197         err = of_property_read_u32_index(np, "st,syscfg", 1,
 198                                          &ddata->boot_offset);
 199         if (err) {
 200                 dev_err(dev, "Boot offset not found\n");
 201                 return -EINVAL;
 202         }
 203
 204         err = of_reserved_mem_device_init(dev);
 205         if (err) {
 206                 dev_err(dev, "Failed to obtain shared memory\n");
 207                 return err;
 208         }
 209
 210         err = clk_prepare(ddata->clk);
 211         if (err)
 212                 dev_err(dev, "failed to get clock\n");
 213
 214         return err;
 215 }
 216
 217 static int st_rproc_probe(struct platform_device *pdev)
 218 {
 219         struct device *dev = &pdev->dev;
 220         const struct of_device_id *match;
 221         struct st_rproc *ddata;
 222         struct device_node *np = dev->of_node;
 223         struct rproc *rproc;
 224         int enabled;
 225         int ret;
 226
 227         match = of_match_device(st_rproc_match, dev);
 228         if (!match || !match->data) {
 229                 dev_err(dev, "No device match found\n");
 230                 return -ENODEV;
 231         }
 232
 233         rproc = rproc_alloc(dev, np->name, &st_rproc_ops, NULL, sizeof(*ddata));
 234         if (!rproc)
 235                 return -ENOMEM;
 236
 237         rproc->has_iommu = false;
 238         ddata = rproc->priv;
 239         ddata->config = (struct st_rproc_config *)match->data;
 240
 241         platform_set_drvdata(pdev, rproc);
 242
 243         ret = st_rproc_parse_dt(pdev);
 244         if (ret)
 245                 goto free_rproc;
 246
 247         enabled = st_rproc_state(pdev);
 248         if (enabled < 0)
 249                 goto free_rproc;
 250
 251         if (enabled) {
 252                 atomic_inc(&rproc->power);
 253                 rproc->state = RPROC_RUNNING;
 254         } else {
 255                 clk_set_rate(ddata->clk, ddata->clk_rate);
 256         }
 257
 258         ret = rproc_add(rproc);
 259         if (ret)
 260                 goto free_rproc;
 261
 262         return 0;
 263
 264 free_rproc:
 265         rproc_put(rproc);
 266         return ret;
 267 }
 268
 269 static int st_rproc_remove(struct platform_device *pdev)
 270 {
 271         struct rproc *rproc = platform_get_drvdata(pdev);
 272         struct st_rproc *ddata = rproc->priv;
 273
 274         rproc_del(rproc);
 275
 276         clk_disable_unprepare(ddata->clk);
 277
 278         of_reserved_mem_device_release(&pdev->dev);
 279
 280         rproc_put(rproc);
 281
 282         return 0;
 283 }
 284
 285 static struct platform_driver st_rproc_driver = {
 286         .probe = st_rproc_probe,
 287         .remove = st_rproc_remove,
 288         .driver = {
 289                 .name = "st-rproc",
 290                 .of_match_table = of_match_ptr(st_rproc_match),
 291         },
 292 };
 293 module_platform_driver(st_rproc_driver);
 294
 295 MODULE_DESCRIPTION("ST Remote Processor Control Driver");
 296 MODULE_AUTHOR("Ludovic Barre <ludovic.barre@st.com>");
 297 MODULE_LICENSE("GPL v2");