xref: /openbmc/linux/drivers/mfd/exynos-lpass.c (revision a44e4f3a)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2015 - 2016 Samsung Electronics Co., Ltd.
4  *
5  * Authors: Inha Song <ideal.song@samsung.com>
6  *          Sylwester Nawrocki <s.nawrocki@samsung.com>
7  *
8  * Samsung Exynos SoC series Low Power Audio Subsystem driver.
9  *
10  * This module provides regmap for the Top SFR region and instantiates
11  * devices for IP blocks like DMAC, I2S, UART.
12  */
13 
14 #include <linux/clk.h>
15 #include <linux/delay.h>
16 #include <linux/io.h>
17 #include <linux/module.h>
18 #include <linux/mfd/syscon.h>
19 #include <linux/of.h>
20 #include <linux/of_platform.h>
21 #include <linux/platform_device.h>
22 #include <linux/pm_runtime.h>
23 #include <linux/regmap.h>
24 #include <linux/soc/samsung/exynos-regs-pmu.h>
25 #include <linux/types.h>
26 
27 /* LPASS Top register definitions */
28 #define SFR_LPASS_CORE_SW_RESET		0x08
29 #define  LPASS_SB_SW_RESET		BIT(11)
30 #define  LPASS_UART_SW_RESET		BIT(10)
31 #define  LPASS_PCM_SW_RESET		BIT(9)
32 #define  LPASS_I2S_SW_RESET		BIT(8)
33 #define  LPASS_WDT1_SW_RESET		BIT(4)
34 #define  LPASS_WDT0_SW_RESET		BIT(3)
35 #define  LPASS_TIMER_SW_RESET		BIT(2)
36 #define  LPASS_MEM_SW_RESET		BIT(1)
37 #define  LPASS_DMA_SW_RESET		BIT(0)
38 
39 #define SFR_LPASS_INTR_CA5_MASK		0x48
40 #define SFR_LPASS_INTR_CPU_MASK		0x58
41 #define  LPASS_INTR_APM			BIT(9)
42 #define  LPASS_INTR_MIF			BIT(8)
43 #define  LPASS_INTR_TIMER		BIT(7)
44 #define  LPASS_INTR_DMA			BIT(6)
45 #define  LPASS_INTR_GPIO		BIT(5)
46 #define  LPASS_INTR_I2S			BIT(4)
47 #define  LPASS_INTR_PCM			BIT(3)
48 #define  LPASS_INTR_SLIMBUS		BIT(2)
49 #define  LPASS_INTR_UART		BIT(1)
50 #define  LPASS_INTR_SFR			BIT(0)
51 
52 struct exynos_lpass {
53 	/* pointer to the LPASS TOP regmap */
54 	struct regmap *top;
55 	struct clk *sfr0_clk;
56 };
57 
58 static void exynos_lpass_core_sw_reset(struct exynos_lpass *lpass, int mask)
59 {
60 	unsigned int val = 0;
61 
62 	regmap_read(lpass->top, SFR_LPASS_CORE_SW_RESET, &val);
63 
64 	val &= ~mask;
65 	regmap_write(lpass->top, SFR_LPASS_CORE_SW_RESET, val);
66 
67 	usleep_range(100, 150);
68 
69 	val |= mask;
70 	regmap_write(lpass->top, SFR_LPASS_CORE_SW_RESET, val);
71 }
72 
73 static void exynos_lpass_enable(struct exynos_lpass *lpass)
74 {
75 	clk_prepare_enable(lpass->sfr0_clk);
76 
77 	/* Unmask SFR, DMA and I2S interrupt */
78 	regmap_write(lpass->top, SFR_LPASS_INTR_CA5_MASK,
79 		     LPASS_INTR_SFR | LPASS_INTR_DMA | LPASS_INTR_I2S);
80 
81 	regmap_write(lpass->top, SFR_LPASS_INTR_CPU_MASK,
82 		     LPASS_INTR_SFR | LPASS_INTR_DMA | LPASS_INTR_I2S |
83 		     LPASS_INTR_UART);
84 
85 	exynos_lpass_core_sw_reset(lpass, LPASS_I2S_SW_RESET);
86 	exynos_lpass_core_sw_reset(lpass, LPASS_DMA_SW_RESET);
87 	exynos_lpass_core_sw_reset(lpass, LPASS_MEM_SW_RESET);
88 	exynos_lpass_core_sw_reset(lpass, LPASS_UART_SW_RESET);
89 }
90 
91 static void exynos_lpass_disable(struct exynos_lpass *lpass)
92 {
93 	/* Mask any unmasked IP interrupt sources */
94 	regmap_write(lpass->top, SFR_LPASS_INTR_CPU_MASK, 0);
95 	regmap_write(lpass->top, SFR_LPASS_INTR_CA5_MASK, 0);
96 
97 	clk_disable_unprepare(lpass->sfr0_clk);
98 }
99 
100 static const struct regmap_config exynos_lpass_reg_conf = {
101 	.reg_bits	= 32,
102 	.reg_stride	= 4,
103 	.val_bits	= 32,
104 	.max_register	= 0xfc,
105 	.fast_io	= true,
106 };
107 
108 static int exynos_lpass_probe(struct platform_device *pdev)
109 {
110 	struct device *dev = &pdev->dev;
111 	struct exynos_lpass *lpass;
112 	void __iomem *base_top;
113 	struct resource *res;
114 
115 	lpass = devm_kzalloc(dev, sizeof(*lpass), GFP_KERNEL);
116 	if (!lpass)
117 		return -ENOMEM;
118 
119 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
120 	base_top = devm_ioremap_resource(dev, res);
121 	if (IS_ERR(base_top))
122 		return PTR_ERR(base_top);
123 
124 	lpass->sfr0_clk = devm_clk_get(dev, "sfr0_ctrl");
125 	if (IS_ERR(lpass->sfr0_clk))
126 		return PTR_ERR(lpass->sfr0_clk);
127 
128 	lpass->top = regmap_init_mmio(dev, base_top,
129 					&exynos_lpass_reg_conf);
130 	if (IS_ERR(lpass->top)) {
131 		dev_err(dev, "LPASS top regmap initialization failed\n");
132 		return PTR_ERR(lpass->top);
133 	}
134 
135 	platform_set_drvdata(pdev, lpass);
136 	pm_runtime_set_active(dev);
137 	pm_runtime_enable(dev);
138 	exynos_lpass_enable(lpass);
139 
140 	return devm_of_platform_populate(dev);
141 }
142 
143 static int exynos_lpass_remove(struct platform_device *pdev)
144 {
145 	struct exynos_lpass *lpass = platform_get_drvdata(pdev);
146 
147 	exynos_lpass_disable(lpass);
148 	pm_runtime_disable(&pdev->dev);
149 	if (!pm_runtime_status_suspended(&pdev->dev))
150 		exynos_lpass_disable(lpass);
151 	regmap_exit(lpass->top);
152 
153 	return 0;
154 }
155 
156 static int __maybe_unused exynos_lpass_suspend(struct device *dev)
157 {
158 	struct exynos_lpass *lpass = dev_get_drvdata(dev);
159 
160 	exynos_lpass_disable(lpass);
161 
162 	return 0;
163 }
164 
165 static int __maybe_unused exynos_lpass_resume(struct device *dev)
166 {
167 	struct exynos_lpass *lpass = dev_get_drvdata(dev);
168 
169 	exynos_lpass_enable(lpass);
170 
171 	return 0;
172 }
173 
174 static const struct dev_pm_ops lpass_pm_ops = {
175 	SET_RUNTIME_PM_OPS(exynos_lpass_suspend, exynos_lpass_resume, NULL)
176 	SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
177 				     pm_runtime_force_resume)
178 };
179 
180 static const struct of_device_id exynos_lpass_of_match[] = {
181 	{ .compatible = "samsung,exynos5433-lpass" },
182 	{ },
183 };
184 MODULE_DEVICE_TABLE(of, exynos_lpass_of_match);
185 
186 static struct platform_driver exynos_lpass_driver = {
187 	.driver = {
188 		.name		= "exynos-lpass",
189 		.pm		= &lpass_pm_ops,
190 		.of_match_table	= exynos_lpass_of_match,
191 	},
192 	.probe	= exynos_lpass_probe,
193 	.remove	= exynos_lpass_remove,
194 };
195 module_platform_driver(exynos_lpass_driver);
196 
197 MODULE_DESCRIPTION("Samsung Low Power Audio Subsystem driver");
198 MODULE_LICENSE("GPL v2");
199