1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * tegra20_das.c - Tegra20 DAS driver
4  *
5  * Author: Stephen Warren <swarren@nvidia.com>
6  * Copyright (C) 2010 - NVIDIA, Inc.
7  */
8 
9 #include <linux/device.h>
10 #include <linux/io.h>
11 #include <linux/module.h>
12 #include <linux/platform_device.h>
13 #include <linux/regmap.h>
14 #include <linux/slab.h>
15 #include <sound/soc.h>
16 #include "tegra20_das.h"
17 
18 #define DRV_NAME "tegra20-das"
19 
20 static struct tegra20_das *das;
21 
tegra20_das_write(u32 reg,u32 val)22 static inline void tegra20_das_write(u32 reg, u32 val)
23 {
24 	regmap_write(das->regmap, reg, val);
25 }
26 
tegra20_das_read(u32 reg)27 static inline u32 tegra20_das_read(u32 reg)
28 {
29 	u32 val;
30 
31 	regmap_read(das->regmap, reg, &val);
32 	return val;
33 }
34 
tegra20_das_connect_dap_to_dac(int dap,int dac)35 int tegra20_das_connect_dap_to_dac(int dap, int dac)
36 {
37 	u32 addr;
38 	u32 reg;
39 
40 	if (!das)
41 		return -ENODEV;
42 
43 	addr = TEGRA20_DAS_DAP_CTRL_SEL +
44 		(dap * TEGRA20_DAS_DAP_CTRL_SEL_STRIDE);
45 	reg = dac << TEGRA20_DAS_DAP_CTRL_SEL_DAP_CTRL_SEL_P;
46 
47 	tegra20_das_write(addr, reg);
48 
49 	return 0;
50 }
51 EXPORT_SYMBOL_GPL(tegra20_das_connect_dap_to_dac);
52 
tegra20_das_connect_dap_to_dap(int dap,int otherdap,int master,int sdata1rx,int sdata2rx)53 int tegra20_das_connect_dap_to_dap(int dap, int otherdap, int master,
54 				   int sdata1rx, int sdata2rx)
55 {
56 	u32 addr;
57 	u32 reg;
58 
59 	if (!das)
60 		return -ENODEV;
61 
62 	addr = TEGRA20_DAS_DAP_CTRL_SEL +
63 		(dap * TEGRA20_DAS_DAP_CTRL_SEL_STRIDE);
64 	reg = (otherdap << TEGRA20_DAS_DAP_CTRL_SEL_DAP_CTRL_SEL_P) |
65 		(!!sdata2rx << TEGRA20_DAS_DAP_CTRL_SEL_DAP_SDATA2_TX_RX_P) |
66 		(!!sdata1rx << TEGRA20_DAS_DAP_CTRL_SEL_DAP_SDATA1_TX_RX_P) |
67 		(!!master << TEGRA20_DAS_DAP_CTRL_SEL_DAP_MS_SEL_P);
68 
69 	tegra20_das_write(addr, reg);
70 
71 	return 0;
72 }
73 EXPORT_SYMBOL_GPL(tegra20_das_connect_dap_to_dap);
74 
tegra20_das_connect_dac_to_dap(int dac,int dap)75 int tegra20_das_connect_dac_to_dap(int dac, int dap)
76 {
77 	u32 addr;
78 	u32 reg;
79 
80 	if (!das)
81 		return -ENODEV;
82 
83 	addr = TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL +
84 		(dac * TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_STRIDE);
85 	reg = dap << TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_CLK_SEL_P |
86 		dap << TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA1_SEL_P |
87 		dap << TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA2_SEL_P;
88 
89 	tegra20_das_write(addr, reg);
90 
91 	return 0;
92 }
93 EXPORT_SYMBOL_GPL(tegra20_das_connect_dac_to_dap);
94 
95 #define LAST_REG(name) \
96 	(TEGRA20_DAS_##name + \
97 	 (TEGRA20_DAS_##name##_STRIDE * (TEGRA20_DAS_##name##_COUNT - 1)))
98 
tegra20_das_wr_rd_reg(struct device * dev,unsigned int reg)99 static bool tegra20_das_wr_rd_reg(struct device *dev, unsigned int reg)
100 {
101 	if (reg <= LAST_REG(DAP_CTRL_SEL))
102 		return true;
103 	if ((reg >= TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL) &&
104 	    (reg <= LAST_REG(DAC_INPUT_DATA_CLK_SEL)))
105 		return true;
106 
107 	return false;
108 }
109 
110 static const struct regmap_config tegra20_das_regmap_config = {
111 	.reg_bits = 32,
112 	.reg_stride = 4,
113 	.val_bits = 32,
114 	.max_register = LAST_REG(DAC_INPUT_DATA_CLK_SEL),
115 	.writeable_reg = tegra20_das_wr_rd_reg,
116 	.readable_reg = tegra20_das_wr_rd_reg,
117 	.cache_type = REGCACHE_FLAT,
118 };
119 
tegra20_das_probe(struct platform_device * pdev)120 static int tegra20_das_probe(struct platform_device *pdev)
121 {
122 	void __iomem *regs;
123 	int ret = 0;
124 
125 	if (das)
126 		return -ENODEV;
127 
128 	das = devm_kzalloc(&pdev->dev, sizeof(struct tegra20_das), GFP_KERNEL);
129 	if (!das) {
130 		ret = -ENOMEM;
131 		goto err;
132 	}
133 	das->dev = &pdev->dev;
134 
135 	regs = devm_platform_ioremap_resource(pdev, 0);
136 	if (IS_ERR(regs)) {
137 		ret = PTR_ERR(regs);
138 		goto err;
139 	}
140 
141 	das->regmap = devm_regmap_init_mmio(&pdev->dev, regs,
142 					    &tegra20_das_regmap_config);
143 	if (IS_ERR(das->regmap)) {
144 		dev_err(&pdev->dev, "regmap init failed\n");
145 		ret = PTR_ERR(das->regmap);
146 		goto err;
147 	}
148 
149 	ret = tegra20_das_connect_dap_to_dac(TEGRA20_DAS_DAP_ID_1,
150 					     TEGRA20_DAS_DAP_SEL_DAC1);
151 	if (ret) {
152 		dev_err(&pdev->dev, "Can't set up DAS DAP connection\n");
153 		goto err;
154 	}
155 	ret = tegra20_das_connect_dac_to_dap(TEGRA20_DAS_DAC_ID_1,
156 					     TEGRA20_DAS_DAC_SEL_DAP1);
157 	if (ret) {
158 		dev_err(&pdev->dev, "Can't set up DAS DAC connection\n");
159 		goto err;
160 	}
161 
162 	ret = tegra20_das_connect_dap_to_dac(TEGRA20_DAS_DAP_ID_3,
163 					     TEGRA20_DAS_DAP_SEL_DAC3);
164 	if (ret) {
165 		dev_err(&pdev->dev, "Can't set up DAS DAP connection\n");
166 		goto err;
167 	}
168 	ret = tegra20_das_connect_dac_to_dap(TEGRA20_DAS_DAC_ID_3,
169 					     TEGRA20_DAS_DAC_SEL_DAP3);
170 	if (ret) {
171 		dev_err(&pdev->dev, "Can't set up DAS DAC connection\n");
172 		goto err;
173 	}
174 
175 	platform_set_drvdata(pdev, das);
176 
177 	return 0;
178 
179 err:
180 	das = NULL;
181 	return ret;
182 }
183 
tegra20_das_remove(struct platform_device * pdev)184 static int tegra20_das_remove(struct platform_device *pdev)
185 {
186 	if (!das)
187 		return -ENODEV;
188 
189 	das = NULL;
190 
191 	return 0;
192 }
193 
194 static const struct of_device_id tegra20_das_of_match[] = {
195 	{ .compatible = "nvidia,tegra20-das", },
196 	{},
197 };
198 
199 static struct platform_driver tegra20_das_driver = {
200 	.probe = tegra20_das_probe,
201 	.remove = tegra20_das_remove,
202 	.driver = {
203 		.name = DRV_NAME,
204 		.of_match_table = tegra20_das_of_match,
205 	},
206 };
207 module_platform_driver(tegra20_das_driver);
208 
209 MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
210 MODULE_DESCRIPTION("Tegra20 DAS driver");
211 MODULE_LICENSE("GPL");
212 MODULE_ALIAS("platform:" DRV_NAME);
213 MODULE_DEVICE_TABLE(of, tegra20_das_of_match);
214