xref: /linux/drivers/mfd/stm32-timers.c (revision a8b70ccf10e38775785d9cb12ead916474549f99)
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");
79