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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * STM32 Low-Power Timer parent driver.
4 * Copyright (C) STMicroelectronics 2017
5 * Author: Fabrice Gasnier <fabrice.gasnier@st.com>
6 * Inspired by Benjamin Gaignard's stm32-timers driver
7 */
8
9#include <linux/mfd/stm32-lptimer.h>
10#include <linux/module.h>
11#include <linux/of_platform.h>
12
13#define STM32_LPTIM_MAX_REGISTER 0x3fc
14
15static const struct regmap_config stm32_lptimer_regmap_cfg = {
16 .reg_bits = 32,
17 .val_bits = 32,
18 .reg_stride = sizeof(u32),
19 .max_register = STM32_LPTIM_MAX_REGISTER,
20 .fast_io = true,
21};
22
23static int stm32_lptimer_detect_encoder(struct stm32_lptimer *ddata)
24{
25 u32 val;
26 int ret;
27
28 /*
29 * Quadrature encoder mode bit can only be written and read back when
30 * Low-Power Timer supports it.
31 */
32 ret = regmap_update_bits(ddata->regmap, STM32_LPTIM_CFGR,
33 STM32_LPTIM_ENC, STM32_LPTIM_ENC);
34 if (ret)
35 return ret;
36
37 ret = regmap_read(ddata->regmap, STM32_LPTIM_CFGR, &val);
38 if (ret)
39 return ret;
40
41 ret = regmap_update_bits(ddata->regmap, STM32_LPTIM_CFGR,
42 STM32_LPTIM_ENC, 0);
43 if (ret)
44 return ret;
45
46 ddata->has_encoder = !!(val & STM32_LPTIM_ENC);
47
48 return 0;
49}
50
51static int stm32_lptimer_probe(struct platform_device *pdev)
52{
53 struct device *dev = &pdev->dev;
54 struct stm32_lptimer *ddata;
55 struct resource *res;
56 void __iomem *mmio;
57 int ret;
58
59 ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
60 if (!ddata)
61 return -ENOMEM;
62
63 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
64 mmio = devm_ioremap_resource(dev, res);
65 if (IS_ERR(mmio))
66 return PTR_ERR(mmio);
67
68 ddata->regmap = devm_regmap_init_mmio_clk(dev, "mux", mmio,
69 &stm32_lptimer_regmap_cfg);
70 if (IS_ERR(ddata->regmap))
71 return PTR_ERR(ddata->regmap);
72
73 ddata->clk = devm_clk_get(dev, NULL);
74 if (IS_ERR(ddata->clk))
75 return PTR_ERR(ddata->clk);
76
77 ret = stm32_lptimer_detect_encoder(ddata);
78 if (ret)
79 return ret;
80
81 platform_set_drvdata(pdev, ddata);
82
83 return devm_of_platform_populate(&pdev->dev);
84}
85
86static const struct of_device_id stm32_lptimer_of_match[] = {
87 { .compatible = "st,stm32-lptimer", },
88 {},
89};
90MODULE_DEVICE_TABLE(of, stm32_lptimer_of_match);
91
92static struct platform_driver stm32_lptimer_driver = {
93 .probe = stm32_lptimer_probe,
94 .driver = {
95 .name = "stm32-lptimer",
96 .of_match_table = stm32_lptimer_of_match,
97 },
98};
99module_platform_driver(stm32_lptimer_driver);
100
101MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
102MODULE_DESCRIPTION("STMicroelectronics STM32 Low-Power Timer");
103MODULE_ALIAS("platform:stm32-lptimer");
104MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * STM32 Low-Power Timer parent driver.
4 * Copyright (C) STMicroelectronics 2017
5 * Author: Fabrice Gasnier <fabrice.gasnier@st.com>
6 * Inspired by Benjamin Gaignard's stm32-timers driver
7 */
8
9#include <linux/mfd/stm32-lptimer.h>
10#include <linux/module.h>
11#include <linux/of_platform.h>
12
13#define STM32_LPTIM_MAX_REGISTER 0x3fc
14
15static const struct regmap_config stm32_lptimer_regmap_cfg = {
16 .reg_bits = 32,
17 .val_bits = 32,
18 .reg_stride = sizeof(u32),
19 .max_register = STM32_LPTIM_MAX_REGISTER,
20};
21
22static int stm32_lptimer_detect_encoder(struct stm32_lptimer *ddata)
23{
24 u32 val;
25 int ret;
26
27 /*
28 * Quadrature encoder mode bit can only be written and read back when
29 * Low-Power Timer supports it.
30 */
31 ret = regmap_update_bits(ddata->regmap, STM32_LPTIM_CFGR,
32 STM32_LPTIM_ENC, STM32_LPTIM_ENC);
33 if (ret)
34 return ret;
35
36 ret = regmap_read(ddata->regmap, STM32_LPTIM_CFGR, &val);
37 if (ret)
38 return ret;
39
40 ret = regmap_update_bits(ddata->regmap, STM32_LPTIM_CFGR,
41 STM32_LPTIM_ENC, 0);
42 if (ret)
43 return ret;
44
45 ddata->has_encoder = !!(val & STM32_LPTIM_ENC);
46
47 return 0;
48}
49
50static int stm32_lptimer_probe(struct platform_device *pdev)
51{
52 struct device *dev = &pdev->dev;
53 struct stm32_lptimer *ddata;
54 struct resource *res;
55 void __iomem *mmio;
56 int ret;
57
58 ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
59 if (!ddata)
60 return -ENOMEM;
61
62 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
63 mmio = devm_ioremap_resource(dev, res);
64 if (IS_ERR(mmio))
65 return PTR_ERR(mmio);
66
67 ddata->regmap = devm_regmap_init_mmio_clk(dev, "mux", mmio,
68 &stm32_lptimer_regmap_cfg);
69 if (IS_ERR(ddata->regmap))
70 return PTR_ERR(ddata->regmap);
71
72 ddata->clk = devm_clk_get(dev, NULL);
73 if (IS_ERR(ddata->clk))
74 return PTR_ERR(ddata->clk);
75
76 ret = stm32_lptimer_detect_encoder(ddata);
77 if (ret)
78 return ret;
79
80 platform_set_drvdata(pdev, ddata);
81
82 return devm_of_platform_populate(&pdev->dev);
83}
84
85static const struct of_device_id stm32_lptimer_of_match[] = {
86 { .compatible = "st,stm32-lptimer", },
87 {},
88};
89MODULE_DEVICE_TABLE(of, stm32_lptimer_of_match);
90
91static struct platform_driver stm32_lptimer_driver = {
92 .probe = stm32_lptimer_probe,
93 .driver = {
94 .name = "stm32-lptimer",
95 .of_match_table = stm32_lptimer_of_match,
96 },
97};
98module_platform_driver(stm32_lptimer_driver);
99
100MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
101MODULE_DESCRIPTION("STMicroelectronics STM32 Low-Power Timer");
102MODULE_ALIAS("platform:stm32-lptimer");
103MODULE_LICENSE("GPL v2");