drivers/mfd/stm32-timers.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) STMicroelectronics 2016
   4  * Author: Benjamin Gaignard <benjamin.gaignard@st.com>
   5  */
   6
   7 #include <linux/mfd/stm32-timers.h>
   8 #include <linux/module.h>
   9 #include <linux/of_platform.h>
  10 #include <linux/reset.h>
  11
  12 static const struct regmap_config stm32_timers_regmap_cfg = {
  13         .reg_bits = 32,
  14         .val_bits = 32,
  15         .reg_stride = sizeof(u32),
  16         .max_register = 0x3fc,
  17 };
  18
  19 static void stm32_timers_get_arr_size(struct stm32_timers *ddata)
  20 {
  21         /*
  22          * Only the available bits will be written so when readback
  23          * we get the maximum value of auto reload register
  24          */
  25         regmap_write(ddata->regmap, TIM_ARR, ~0L);
  26         regmap_read(ddata->regmap, TIM_ARR, &ddata->max_arr);
  27         regmap_write(ddata->regmap, TIM_ARR, 0x0);
  28 }
  29
  30 static int stm32_timers_probe(struct platform_device *pdev)
  31 {
  32         struct device *dev = &pdev->dev;
  33         struct stm32_timers *ddata;
  34         struct resource *res;
  35         void __iomem *mmio;
  36
  37         ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
  38         if (!ddata)
  39                 return -ENOMEM;
  40
  41         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  42         mmio = devm_ioremap_resource(dev, res);
  43         if (IS_ERR(mmio))
  44                 return PTR_ERR(mmio);
  45
  46         ddata->regmap = devm_regmap_init_mmio_clk(dev, "int", mmio,
  47                                                   &stm32_timers_regmap_cfg);
  48         if (IS_ERR(ddata->regmap))
  49                 return PTR_ERR(ddata->regmap);
  50
  51         ddata->clk = devm_clk_get(dev, NULL);
  52         if (IS_ERR(ddata->clk))
  53                 return PTR_ERR(ddata->clk);
  54
  55         stm32_timers_get_arr_size(ddata);
  56
  57         platform_set_drvdata(pdev, ddata);
  58
  59         return devm_of_platform_populate(&pdev->dev);
  60 }
  61
  62 static const struct of_device_id stm32_timers_of_match[] = {
  63         { .compatible = "st,stm32-timers", },
  64         { /* end node */ },
  65 };
  66 MODULE_DEVICE_TABLE(of, stm32_timers_of_match);
  67
  68 static struct platform_driver stm32_timers_driver = {
  69         .probe = stm32_timers_probe,
  70         .driver = {
  71                 .name = "stm32-timers",
  72                 .of_match_table = stm32_timers_of_match,
  73         },
  74 };
  75 module_platform_driver(stm32_timers_driver);
  76
  77 MODULE_DESCRIPTION("STMicroelectronics STM32 Timers");
  78 MODULE_LICENSE("GPL v2");