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
79struct 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
99static inline void tegra20_das_write(struct tegra20_das *das, u32 reg, u32 val)
100{
101	regmap_write(das->regmap, reg, val);
102}
103
104static 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
116static 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
134static 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
145static 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
155static 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
187static const struct of_device_id tegra20_das_of_match[] = {
188	{ .compatible = "nvidia,tegra20-das", },
189	{},
190};
191
192static 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};
199module_platform_driver(tegra20_das_driver);
200
201MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
202MODULE_DESCRIPTION("Tegra20 DAS driver");
203MODULE_LICENSE("GPL");
204MODULE_ALIAS("platform:" DRV_NAME);
205MODULE_DEVICE_TABLE(of, tegra20_das_of_match);
206