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
17 #define DRV_NAME "tegra20-das"
18
19 /* Register TEGRA20_DAS_DAP_CTRL_SEL */
20 #define TEGRA20_DAS_DAP_CTRL_SEL 0x00
21 #define TEGRA20_DAS_DAP_CTRL_SEL_COUNT 5
22 #define TEGRA20_DAS_DAP_CTRL_SEL_STRIDE 4
23 #define TEGRA20_DAS_DAP_CTRL_SEL_DAP_MS_SEL_P 31
24 #define TEGRA20_DAS_DAP_CTRL_SEL_DAP_MS_SEL_S 1
25 #define TEGRA20_DAS_DAP_CTRL_SEL_DAP_SDATA1_TX_RX_P 30
26 #define TEGRA20_DAS_DAP_CTRL_SEL_DAP_SDATA1_TX_RX_S 1
27 #define TEGRA20_DAS_DAP_CTRL_SEL_DAP_SDATA2_TX_RX_P 29
28 #define TEGRA20_DAS_DAP_CTRL_SEL_DAP_SDATA2_TX_RX_S 1
29 #define TEGRA20_DAS_DAP_CTRL_SEL_DAP_CTRL_SEL_P 0
30 #define TEGRA20_DAS_DAP_CTRL_SEL_DAP_CTRL_SEL_S 5
31
32 /* Values for field TEGRA20_DAS_DAP_CTRL_SEL_DAP_CTRL_SEL */
33 #define TEGRA20_DAS_DAP_SEL_DAC1 0
34 #define TEGRA20_DAS_DAP_SEL_DAC2 1
35 #define TEGRA20_DAS_DAP_SEL_DAC3 2
36 #define TEGRA20_DAS_DAP_SEL_DAP1 16
37 #define TEGRA20_DAS_DAP_SEL_DAP2 17
38 #define TEGRA20_DAS_DAP_SEL_DAP3 18
39 #define TEGRA20_DAS_DAP_SEL_DAP4 19
40 #define TEGRA20_DAS_DAP_SEL_DAP5 20
41
42 /* Register TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL */
43 #define TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL 0x40
44 #define TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_COUNT 3
45 #define TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_STRIDE 4
46 #define TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA2_SEL_P 28
47 #define TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA2_SEL_S 4
48 #define TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA1_SEL_P 24
49 #define TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA1_SEL_S 4
50 #define TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_CLK_SEL_P 0
51 #define TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_CLK_SEL_S 4
52
53 /*
54 * Values for:
55 * TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA2_SEL
56 * TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA1_SEL
57 * TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_CLK_SEL
58 */
59 #define TEGRA20_DAS_DAC_SEL_DAP1 0
60 #define TEGRA20_DAS_DAC_SEL_DAP2 1
61 #define TEGRA20_DAS_DAC_SEL_DAP3 2
62 #define TEGRA20_DAS_DAC_SEL_DAP4 3
63 #define TEGRA20_DAS_DAC_SEL_DAP5 4
64
65 /*
66 * Names/IDs of the DACs/DAPs.
67 */
68
69 #define TEGRA20_DAS_DAP_ID_1 0
70 #define TEGRA20_DAS_DAP_ID_2 1
71 #define TEGRA20_DAS_DAP_ID_3 2
72 #define TEGRA20_DAS_DAP_ID_4 3
73 #define TEGRA20_DAS_DAP_ID_5 4
74
75 #define TEGRA20_DAS_DAC_ID_1 0
76 #define TEGRA20_DAS_DAC_ID_2 1
77 #define TEGRA20_DAS_DAC_ID_3 2
78
79 struct tegra20_das {
80 struct regmap *regmap;
81 };
82
83 /*
84 * Terminology:
85 * DAS: Digital audio switch (HW module controlled by this driver)
86 * DAP: Digital audio port (port/pins on Tegra device)
87 * DAC: Digital audio controller (e.g. I2S or AC97 controller elsewhere)
88 *
89 * The Tegra DAS is a mux/cross-bar which can connect each DAP to a specific
90 * DAC, or another DAP. When DAPs are connected, one must be the master and
91 * one the slave. Each DAC allows selection of a specific DAP for input, to
92 * cater for the case where N DAPs are connected to 1 DAC for broadcast
93 * output.
94 *
95 * This driver is dumb; no attempt is made to ensure that a valid routing
96 * configuration is programmed.
97 */
98
99 static inline void tegra20_das_write(struct tegra20_das *das, u32 reg, u32 val)
100 {
101 regmap_write(das->regmap, reg, val);
102 }
103
104 static void tegra20_das_connect_dap_to_dac(struct tegra20_das *das, int dap, int dac)
105 {
106 u32 addr;
107 u32 reg;
108
109 addr = TEGRA20_DAS_DAP_CTRL_SEL +
110 (dap * TEGRA20_DAS_DAP_CTRL_SEL_STRIDE);
111 reg = dac << TEGRA20_DAS_DAP_CTRL_SEL_DAP_CTRL_SEL_P;
112
113 tegra20_das_write(das, addr, reg);
114 }
115
116 static void tegra20_das_connect_dac_to_dap(struct tegra20_das *das, int dac, int dap)
117 {
118 u32 addr;
119 u32 reg;
120
121 addr = TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL +
122 (dac * TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_STRIDE);
123 reg = dap << TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_CLK_SEL_P |
124 dap << TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA1_SEL_P |
125 dap << TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA2_SEL_P;
126
127 tegra20_das_write(das, addr, reg);
128 }
129
130 #define LAST_REG(name) \
131 (TEGRA20_DAS_##name + \
132 (TEGRA20_DAS_##name##_STRIDE * (TEGRA20_DAS_##name##_COUNT - 1)))
133
134 static bool tegra20_das_wr_rd_reg(struct device *dev, unsigned int reg)
135 {
136 if (reg <= LAST_REG(DAP_CTRL_SEL))
137 return true;
138 if ((reg >= TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL) &&
139 (reg <= LAST_REG(DAC_INPUT_DATA_CLK_SEL)))
140 return true;
141
142 return false;
143 }
144
145 static const struct regmap_config tegra20_das_regmap_config = {
146 .reg_bits = 32,
147 .reg_stride = 4,
148 .val_bits = 32,
149 .max_register = LAST_REG(DAC_INPUT_DATA_CLK_SEL),
150 .writeable_reg = tegra20_das_wr_rd_reg,
151 .readable_reg = tegra20_das_wr_rd_reg,
152 .cache_type = REGCACHE_FLAT,
153 };
154
155 static int tegra20_das_probe(struct platform_device *pdev)
156 {
157 void __iomem *regs;
158 struct tegra20_das *das;
159
160 das = devm_kzalloc(&pdev->dev, sizeof(struct tegra20_das), GFP_KERNEL);
161 if (!das)
162 return -ENOMEM;
163
164 regs = devm_platform_ioremap_resource(pdev, 0);
165 if (IS_ERR(regs))
166 return PTR_ERR(regs);
167
168 das->regmap = devm_regmap_init_mmio(&pdev->dev, regs,
169 &tegra20_das_regmap_config);
170 if (IS_ERR(das->regmap)) {
171 dev_err(&pdev->dev, "regmap init failed\n");
172 return PTR_ERR(das->regmap);
173 }
174
175 tegra20_das_connect_dap_to_dac(das, TEGRA20_DAS_DAP_ID_1,
176 TEGRA20_DAS_DAP_SEL_DAC1);
177 tegra20_das_connect_dac_to_dap(das, TEGRA20_DAS_DAC_ID_1,
178 TEGRA20_DAS_DAC_SEL_DAP1);
179 tegra20_das_connect_dap_to_dac(das, TEGRA20_DAS_DAP_ID_3,
180 TEGRA20_DAS_DAP_SEL_DAC3);
181 tegra20_das_connect_dac_to_dap(das, TEGRA20_DAS_DAC_ID_3,
182 TEGRA20_DAS_DAC_SEL_DAP3);
183
184 return 0;
185 }
186
187 static const struct of_device_id tegra20_das_of_match[] = {
188 { .compatible = "nvidia,tegra20-das", },
189 {},
190 };
191
192 static struct platform_driver tegra20_das_driver = {
193 .probe = tegra20_das_probe,
194 .driver = {
195 .name = DRV_NAME,
196 .of_match_table = tegra20_das_of_match,
197 },
198 };
199 module_platform_driver(tegra20_das_driver);
200
201 MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
202 MODULE_DESCRIPTION("Tegra20 DAS driver");
203 MODULE_LICENSE("GPL");
204 MODULE_ALIAS("platform:" DRV_NAME);
205 MODULE_DEVICE_TABLE(of, tegra20_das_of_match);
206
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