xref: /openbmc/linux/drivers/mfd/exynos-lpass.c (revision e285d5bf)
1 /*
2  * Copyright (C) 2015 - 2016 Samsung Electronics Co., Ltd.
3  *
4  * Authors: Inha Song <ideal.song@samsung.com>
5  *          Sylwester Nawrocki <s.nawrocki@samsung.com>
6  *
7  * Samsung Exynos SoC series Low Power Audio Subsystem driver.
8  *
9  * This module provides regmap for the Top SFR region and instantiates
10  * devices for IP blocks like DMAC, I2S, UART.
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License version 2 and
14  * only version 2 as published by the Free Software Foundation.
15  */
16 
17 #include <linux/clk.h>
18 #include <linux/delay.h>
19 #include <linux/io.h>
20 #include <linux/module.h>
21 #include <linux/mfd/syscon.h>
22 #include <linux/of.h>
23 #include <linux/of_platform.h>
24 #include <linux/platform_device.h>
25 #include <linux/pm_runtime.h>
26 #include <linux/regmap.h>
27 #include <linux/soc/samsung/exynos-regs-pmu.h>
28 #include <linux/types.h>
29 
30 /* LPASS Top register definitions */
31 #define SFR_LPASS_CORE_SW_RESET		0x08
32 #define  LPASS_SB_SW_RESET		BIT(11)
33 #define  LPASS_UART_SW_RESET		BIT(10)
34 #define  LPASS_PCM_SW_RESET		BIT(9)
35 #define  LPASS_I2S_SW_RESET		BIT(8)
36 #define  LPASS_WDT1_SW_RESET		BIT(4)
37 #define  LPASS_WDT0_SW_RESET		BIT(3)
38 #define  LPASS_TIMER_SW_RESET		BIT(2)
39 #define  LPASS_MEM_SW_RESET		BIT(1)
40 #define  LPASS_DMA_SW_RESET		BIT(0)
41 
42 #define SFR_LPASS_INTR_CA5_MASK		0x48
43 #define SFR_LPASS_INTR_CPU_MASK		0x58
44 #define  LPASS_INTR_APM			BIT(9)
45 #define  LPASS_INTR_MIF			BIT(8)
46 #define  LPASS_INTR_TIMER		BIT(7)
47 #define  LPASS_INTR_DMA			BIT(6)
48 #define  LPASS_INTR_GPIO		BIT(5)
49 #define  LPASS_INTR_I2S			BIT(4)
50 #define  LPASS_INTR_PCM			BIT(3)
51 #define  LPASS_INTR_SLIMBUS		BIT(2)
52 #define  LPASS_INTR_UART		BIT(1)
53 #define  LPASS_INTR_SFR			BIT(0)
54 
55 struct exynos_lpass {
56 	/* pointer to the LPASS TOP regmap */
57 	struct regmap *top;
58 	struct clk *sfr0_clk;
59 };
60 
61 static void exynos_lpass_core_sw_reset(struct exynos_lpass *lpass, int mask)
62 {
63 	unsigned int val = 0;
64 
65 	regmap_read(lpass->top, SFR_LPASS_CORE_SW_RESET, &val);
66 
67 	val &= ~mask;
68 	regmap_write(lpass->top, SFR_LPASS_CORE_SW_RESET, val);
69 
70 	usleep_range(100, 150);
71 
72 	val |= mask;
73 	regmap_write(lpass->top, SFR_LPASS_CORE_SW_RESET, val);
74 }
75 
76 static void exynos_lpass_enable(struct exynos_lpass *lpass)
77 {
78 	clk_prepare_enable(lpass->sfr0_clk);
79 
80 	/* Unmask SFR, DMA and I2S interrupt */
81 	regmap_write(lpass->top, SFR_LPASS_INTR_CA5_MASK,
82 		     LPASS_INTR_SFR | LPASS_INTR_DMA | LPASS_INTR_I2S);
83 
84 	regmap_write(lpass->top, SFR_LPASS_INTR_CPU_MASK,
85 		     LPASS_INTR_SFR | LPASS_INTR_DMA | LPASS_INTR_I2S);
86 
87 	exynos_lpass_core_sw_reset(lpass, LPASS_I2S_SW_RESET);
88 	exynos_lpass_core_sw_reset(lpass, LPASS_DMA_SW_RESET);
89 	exynos_lpass_core_sw_reset(lpass, LPASS_MEM_SW_RESET);
90 }
91 
92 static void exynos_lpass_disable(struct exynos_lpass *lpass)
93 {
94 	/* Mask any unmasked IP interrupt sources */
95 	regmap_write(lpass->top, SFR_LPASS_INTR_CPU_MASK, 0);
96 	regmap_write(lpass->top, SFR_LPASS_INTR_CA5_MASK, 0);
97 
98 	clk_disable_unprepare(lpass->sfr0_clk);
99 }
100 
101 static const struct regmap_config exynos_lpass_reg_conf = {
102 	.reg_bits	= 32,
103 	.reg_stride	= 4,
104 	.val_bits	= 32,
105 	.max_register	= 0xfc,
106 	.fast_io	= true,
107 };
108 
109 static int exynos_lpass_probe(struct platform_device *pdev)
110 {
111 	struct device *dev = &pdev->dev;
112 	struct exynos_lpass *lpass;
113 	void __iomem *base_top;
114 	struct resource *res;
115 
116 	lpass = devm_kzalloc(dev, sizeof(*lpass), GFP_KERNEL);
117 	if (!lpass)
118 		return -ENOMEM;
119 
120 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
121 	base_top = devm_ioremap_resource(dev, res);
122 	if (IS_ERR(base_top))
123 		return PTR_ERR(base_top);
124 
125 	lpass->sfr0_clk = devm_clk_get(dev, "sfr0_ctrl");
126 	if (IS_ERR(lpass->sfr0_clk))
127 		return PTR_ERR(lpass->sfr0_clk);
128 
129 	lpass->top = regmap_init_mmio(dev, base_top,
130 					&exynos_lpass_reg_conf);
131 	if (IS_ERR(lpass->top)) {
132 		dev_err(dev, "LPASS top regmap initialization failed\n");
133 		return PTR_ERR(lpass->top);
134 	}
135 
136 	platform_set_drvdata(pdev, lpass);
137 	pm_runtime_set_active(dev);
138 	pm_runtime_enable(dev);
139 	exynos_lpass_enable(lpass);
140 
141 	return devm_of_platform_populate(dev);
142 }
143 
144 static int exynos_lpass_remove(struct platform_device *pdev)
145 {
146 	struct exynos_lpass *lpass = platform_get_drvdata(pdev);
147 
148 	exynos_lpass_disable(lpass);
149 	pm_runtime_disable(&pdev->dev);
150 	if (!pm_runtime_status_suspended(&pdev->dev))
151 		exynos_lpass_disable(lpass);
152 	regmap_exit(lpass->top);
153 
154 	return 0;
155 }
156 
157 static int __maybe_unused exynos_lpass_suspend(struct device *dev)
158 {
159 	struct exynos_lpass *lpass = dev_get_drvdata(dev);
160 
161 	exynos_lpass_disable(lpass);
162 
163 	return 0;
164 }
165 
166 static int __maybe_unused exynos_lpass_resume(struct device *dev)
167 {
168 	struct exynos_lpass *lpass = dev_get_drvdata(dev);
169 
170 	exynos_lpass_enable(lpass);
171 
172 	return 0;
173 }
174 
175 static const struct dev_pm_ops lpass_pm_ops = {
176 	SET_RUNTIME_PM_OPS(exynos_lpass_suspend, exynos_lpass_resume, NULL)
177 	SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
178 				     pm_runtime_force_resume)
179 };
180 
181 static const struct of_device_id exynos_lpass_of_match[] = {
182 	{ .compatible = "samsung,exynos5433-lpass" },
183 	{ },
184 };
185 MODULE_DEVICE_TABLE(of, exynos_lpass_of_match);
186 
187 static struct platform_driver exynos_lpass_driver = {
188 	.driver = {
189 		.name		= "exynos-lpass",
190 		.pm		= &lpass_pm_ops,
191 		.of_match_table	= exynos_lpass_of_match,
192 	},
193 	.probe	= exynos_lpass_probe,
194 	.remove	= exynos_lpass_remove,
195 };
196 module_platform_driver(exynos_lpass_driver);
197 
198 MODULE_DESCRIPTION("Samsung Low Power Audio Subsystem driver");
199 MODULE_LICENSE("GPL v2");
200