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