xref: /openbmc/linux/drivers/mfd/exynos-lpass.c (revision be709d48)
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 		     LPASS_INTR_UART);
87 
88 	exynos_lpass_core_sw_reset(lpass, LPASS_I2S_SW_RESET);
89 	exynos_lpass_core_sw_reset(lpass, LPASS_DMA_SW_RESET);
90 	exynos_lpass_core_sw_reset(lpass, LPASS_MEM_SW_RESET);
91 	exynos_lpass_core_sw_reset(lpass, LPASS_UART_SW_RESET);
92 }
93 
94 static void exynos_lpass_disable(struct exynos_lpass *lpass)
95 {
96 	/* Mask any unmasked IP interrupt sources */
97 	regmap_write(lpass->top, SFR_LPASS_INTR_CPU_MASK, 0);
98 	regmap_write(lpass->top, SFR_LPASS_INTR_CA5_MASK, 0);
99 
100 	clk_disable_unprepare(lpass->sfr0_clk);
101 }
102 
103 static const struct regmap_config exynos_lpass_reg_conf = {
104 	.reg_bits	= 32,
105 	.reg_stride	= 4,
106 	.val_bits	= 32,
107 	.max_register	= 0xfc,
108 	.fast_io	= true,
109 };
110 
111 static int exynos_lpass_probe(struct platform_device *pdev)
112 {
113 	struct device *dev = &pdev->dev;
114 	struct exynos_lpass *lpass;
115 	void __iomem *base_top;
116 	struct resource *res;
117 
118 	lpass = devm_kzalloc(dev, sizeof(*lpass), GFP_KERNEL);
119 	if (!lpass)
120 		return -ENOMEM;
121 
122 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
123 	base_top = devm_ioremap_resource(dev, res);
124 	if (IS_ERR(base_top))
125 		return PTR_ERR(base_top);
126 
127 	lpass->sfr0_clk = devm_clk_get(dev, "sfr0_ctrl");
128 	if (IS_ERR(lpass->sfr0_clk))
129 		return PTR_ERR(lpass->sfr0_clk);
130 
131 	lpass->top = regmap_init_mmio(dev, base_top,
132 					&exynos_lpass_reg_conf);
133 	if (IS_ERR(lpass->top)) {
134 		dev_err(dev, "LPASS top regmap initialization failed\n");
135 		return PTR_ERR(lpass->top);
136 	}
137 
138 	platform_set_drvdata(pdev, lpass);
139 	pm_runtime_set_active(dev);
140 	pm_runtime_enable(dev);
141 	exynos_lpass_enable(lpass);
142 
143 	return devm_of_platform_populate(dev);
144 }
145 
146 static int exynos_lpass_remove(struct platform_device *pdev)
147 {
148 	struct exynos_lpass *lpass = platform_get_drvdata(pdev);
149 
150 	exynos_lpass_disable(lpass);
151 	pm_runtime_disable(&pdev->dev);
152 	if (!pm_runtime_status_suspended(&pdev->dev))
153 		exynos_lpass_disable(lpass);
154 	regmap_exit(lpass->top);
155 
156 	return 0;
157 }
158 
159 static int __maybe_unused exynos_lpass_suspend(struct device *dev)
160 {
161 	struct exynos_lpass *lpass = dev_get_drvdata(dev);
162 
163 	exynos_lpass_disable(lpass);
164 
165 	return 0;
166 }
167 
168 static int __maybe_unused exynos_lpass_resume(struct device *dev)
169 {
170 	struct exynos_lpass *lpass = dev_get_drvdata(dev);
171 
172 	exynos_lpass_enable(lpass);
173 
174 	return 0;
175 }
176 
177 static const struct dev_pm_ops lpass_pm_ops = {
178 	SET_RUNTIME_PM_OPS(exynos_lpass_suspend, exynos_lpass_resume, NULL)
179 	SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
180 				     pm_runtime_force_resume)
181 };
182 
183 static const struct of_device_id exynos_lpass_of_match[] = {
184 	{ .compatible = "samsung,exynos5433-lpass" },
185 	{ },
186 };
187 MODULE_DEVICE_TABLE(of, exynos_lpass_of_match);
188 
189 static struct platform_driver exynos_lpass_driver = {
190 	.driver = {
191 		.name		= "exynos-lpass",
192 		.pm		= &lpass_pm_ops,
193 		.of_match_table	= exynos_lpass_of_match,
194 	},
195 	.probe	= exynos_lpass_probe,
196 	.remove	= exynos_lpass_remove,
197 };
198 module_platform_driver(exynos_lpass_driver);
199 
200 MODULE_DESCRIPTION("Samsung Low Power Audio Subsystem driver");
201 MODULE_LICENSE("GPL v2");
202