1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2022 Texas Instruments Incorporated - https://www.ti.com/
4  */
5 
6 #include <linux/bitfield.h>
7 #include <linux/bitops.h>
8 #include <linux/io.h>
9 #include <linux/iopoll.h>
10 #include <linux/module.h>
11 #include <linux/phy/phy.h>
12 #include <linux/phy/phy-mipi-dphy.h>
13 #include <linux/platform_device.h>
14 #include <linux/sys_soc.h>
15 
16 #define DPHY_PMA_CMN(reg)		(reg)
17 #define DPHY_PCS(reg)			(0xb00 + (reg))
18 #define DPHY_ISO(reg)			(0xc00 + (reg))
19 #define DPHY_WRAP(reg)			(0x1000 + (reg))
20 
21 #define DPHY_CMN_SSM			DPHY_PMA_CMN(0x20)
22 #define DPHY_CMN_RX_MODE_EN		BIT(10)
23 #define DPHY_CMN_RX_BANDGAP_TIMER_MASK	GENMASK(8, 1)
24 #define DPHY_CMN_SSM_EN			BIT(0)
25 
26 #define DPHY_CMN_RX_BANDGAP_TIMER	0x14
27 
28 #define DPHY_BAND_CFG			DPHY_PCS(0x0)
29 #define DPHY_BAND_CFG_RIGHT_BAND	GENMASK(9, 5)
30 #define DPHY_BAND_CFG_LEFT_BAND		GENMASK(4, 0)
31 
32 #define DPHY_POWER_ISLAND_EN_DATA	DPHY_PCS(0x8)
33 #define DPHY_POWER_ISLAND_EN_DATA_VAL	0xaaaaaaaa
34 
35 #define DPHY_POWER_ISLAND_EN_CLK	DPHY_PCS(0xc)
36 #define DPHY_POWER_ISLAND_EN_CLK_VAL	0xaa
37 
38 #define DPHY_LANE			DPHY_WRAP(0x0)
39 #define DPHY_LANE_RESET_CMN_EN		BIT(23)
40 
41 #define DPHY_ISO_CL_CTRL_L		DPHY_ISO(0x10)
42 #define DPHY_ISO_DL_CTRL_L0		DPHY_ISO(0x14)
43 #define DPHY_ISO_DL_CTRL_L1		DPHY_ISO(0x20)
44 #define DPHY_ISO_DL_CTRL_L2		DPHY_ISO(0x30)
45 #define DPHY_ISO_DL_CTRL_L3		DPHY_ISO(0x3c)
46 
47 #define DPHY_ISO_LANE_READY_BIT		0
48 #define DPHY_ISO_LANE_READY_TIMEOUT_MS	100UL
49 
50 #define DPHY_LANES_MIN			1
51 #define DPHY_LANES_MAX			4
52 
53 struct cdns_dphy_rx {
54 	void __iomem *regs;
55 	struct device *dev;
56 	struct phy *phy;
57 };
58 
59 struct cdns_dphy_rx_band {
60 	/* Rates are in Mbps. */
61 	unsigned int min_rate;
62 	unsigned int max_rate;
63 };
64 
65 struct cdns_dphy_soc_data {
66 	bool has_hw_cmn_rstb;
67 };
68 
69 /* Order of bands is important since the index is the band number. */
70 static const struct cdns_dphy_rx_band bands[] = {
71 	{ 80, 100 }, { 100, 120 }, { 120, 160 }, { 160, 200 }, { 200, 240 },
72 	{ 240, 280 }, { 280, 320 }, { 320, 360 }, { 360, 400 }, { 400, 480 },
73 	{ 480, 560 }, { 560, 640 }, { 640, 720 }, { 720, 800 }, { 800, 880 },
74 	{ 880, 1040 }, { 1040, 1200 }, { 1200, 1350 }, { 1350, 1500 },
75 	{ 1500, 1750 }, { 1750, 2000 }, { 2000, 2250 }, { 2250, 2500 }
76 };
77 
78 static int cdns_dphy_rx_power_on(struct phy *phy)
79 {
80 	struct cdns_dphy_rx *dphy = phy_get_drvdata(phy);
81 
82 	/* Start RX state machine. */
83 	writel(DPHY_CMN_SSM_EN | DPHY_CMN_RX_MODE_EN |
84 	       FIELD_PREP(DPHY_CMN_RX_BANDGAP_TIMER_MASK,
85 			  DPHY_CMN_RX_BANDGAP_TIMER),
86 	       dphy->regs + DPHY_CMN_SSM);
87 
88 	return 0;
89 }
90 
91 static int cdns_dphy_rx_power_off(struct phy *phy)
92 {
93 	struct cdns_dphy_rx *dphy = phy_get_drvdata(phy);
94 
95 	writel(0, dphy->regs + DPHY_CMN_SSM);
96 
97 	return 0;
98 }
99 
100 static int cdns_dphy_rx_get_band_ctrl(unsigned long hs_clk_rate)
101 {
102 	unsigned int rate, i;
103 
104 	rate = hs_clk_rate / 1000000UL;
105 	/* Since CSI-2 clock is DDR, the bit rate is twice the clock rate. */
106 	rate *= 2;
107 
108 	if (rate < bands[0].min_rate)
109 		return -EOPNOTSUPP;
110 
111 	for (i = 0; i < ARRAY_SIZE(bands); i++)
112 		if (rate < bands[i].max_rate)
113 			return i;
114 
115 	return -EOPNOTSUPP;
116 }
117 
118 static inline int cdns_dphy_rx_wait_for_bit(void __iomem *addr,
119 					    unsigned int bit)
120 {
121 	u32 val;
122 
123 	return readl_relaxed_poll_timeout(addr, val, val & BIT(bit), 10,
124 					  DPHY_ISO_LANE_READY_TIMEOUT_MS * 1000);
125 }
126 
127 static int cdns_dphy_rx_wait_lane_ready(struct cdns_dphy_rx *dphy,
128 					unsigned int lanes)
129 {
130 	static const u32 data_lane_ctrl[] = {DPHY_ISO_DL_CTRL_L0,
131 					     DPHY_ISO_DL_CTRL_L1,
132 					     DPHY_ISO_DL_CTRL_L2,
133 					     DPHY_ISO_DL_CTRL_L3};
134 	void __iomem *reg = dphy->regs;
135 	unsigned int i;
136 	int ret;
137 
138 	/* Clock lane */
139 	ret = cdns_dphy_rx_wait_for_bit(reg + DPHY_ISO_CL_CTRL_L,
140 					DPHY_ISO_LANE_READY_BIT);
141 	if (ret)
142 		return ret;
143 
144 	for (i = 0; i < lanes; i++) {
145 		ret = cdns_dphy_rx_wait_for_bit(reg + data_lane_ctrl[i],
146 						DPHY_ISO_LANE_READY_BIT);
147 		if (ret)
148 			return ret;
149 	}
150 
151 	return 0;
152 }
153 
154 static struct cdns_dphy_soc_data j721e_soc_data = {
155 	.has_hw_cmn_rstb = true,
156 };
157 
158 static const struct soc_device_attribute cdns_dphy_socinfo[] = {
159 	{
160 		.family = "J721E",
161 		.revision = "SR1.0",
162 		.data = &j721e_soc_data,
163 	},
164 	{/* sentinel */}
165 };
166 
167 static int cdns_dphy_rx_configure(struct phy *phy,
168 				  union phy_configure_opts *opts)
169 {
170 	struct cdns_dphy_rx *dphy = phy_get_drvdata(phy);
171 	unsigned int reg, lanes = opts->mipi_dphy.lanes;
172 	const struct cdns_dphy_soc_data *soc_data = NULL;
173 	const struct soc_device_attribute *soc;
174 	int band_ctrl, ret;
175 
176 	soc = soc_device_match(cdns_dphy_socinfo);
177 	if (soc && soc->data)
178 		soc_data = soc->data;
179 	if (!soc || (soc_data && !soc_data->has_hw_cmn_rstb)) {
180 		reg = DPHY_LANE_RESET_CMN_EN;
181 		writel(reg, dphy->regs + DPHY_LANE);
182 	}
183 
184 	/* Data lanes. Minimum one lane is mandatory. */
185 	if (lanes < DPHY_LANES_MIN || lanes > DPHY_LANES_MAX)
186 		return -EINVAL;
187 
188 	band_ctrl = cdns_dphy_rx_get_band_ctrl(opts->mipi_dphy.hs_clk_rate);
189 	if (band_ctrl < 0)
190 		return band_ctrl;
191 
192 	reg = FIELD_PREP(DPHY_BAND_CFG_LEFT_BAND, band_ctrl) |
193 	      FIELD_PREP(DPHY_BAND_CFG_RIGHT_BAND, band_ctrl);
194 	writel(reg, dphy->regs + DPHY_BAND_CFG);
195 
196 	/*
197 	 * Set the required power island phase 2 time. This is mandated by DPHY
198 	 * specs.
199 	 */
200 	reg = DPHY_POWER_ISLAND_EN_DATA_VAL;
201 	writel(reg, dphy->regs + DPHY_POWER_ISLAND_EN_DATA);
202 	reg = DPHY_POWER_ISLAND_EN_CLK_VAL;
203 	writel(reg, dphy->regs + DPHY_POWER_ISLAND_EN_CLK);
204 
205 	ret = cdns_dphy_rx_wait_lane_ready(dphy, lanes);
206 	if (ret) {
207 		dev_err(dphy->dev, "DPHY wait for lane ready timeout\n");
208 		return ret;
209 	}
210 
211 	return 0;
212 }
213 
214 static int cdns_dphy_rx_validate(struct phy *phy, enum phy_mode mode,
215 				 int submode, union phy_configure_opts *opts)
216 {
217 	int ret;
218 
219 	if (mode != PHY_MODE_MIPI_DPHY)
220 		return -EINVAL;
221 
222 	ret = cdns_dphy_rx_get_band_ctrl(opts->mipi_dphy.hs_clk_rate);
223 	if (ret < 0)
224 		return ret;
225 
226 	return phy_mipi_dphy_config_validate(&opts->mipi_dphy);
227 }
228 
229 static const struct phy_ops cdns_dphy_rx_ops = {
230 	.power_on = cdns_dphy_rx_power_on,
231 	.power_off = cdns_dphy_rx_power_off,
232 	.configure = cdns_dphy_rx_configure,
233 	.validate = cdns_dphy_rx_validate,
234 };
235 
236 static int cdns_dphy_rx_probe(struct platform_device *pdev)
237 {
238 	struct device *dev = &pdev->dev;
239 	struct phy_provider *provider;
240 	struct cdns_dphy_rx *dphy;
241 
242 	dphy = devm_kzalloc(dev, sizeof(*dphy), GFP_KERNEL);
243 	if (!dphy)
244 		return -ENOMEM;
245 
246 	dev_set_drvdata(dev, dphy);
247 	dphy->dev = dev;
248 
249 	dphy->regs = devm_platform_ioremap_resource(pdev, 0);
250 	if (IS_ERR(dphy->regs))
251 		return PTR_ERR(dphy->regs);
252 
253 	dphy->phy = devm_phy_create(dev, NULL, &cdns_dphy_rx_ops);
254 	if (IS_ERR(dphy->phy)) {
255 		dev_err(dev, "Failed to create PHY: %ld\n", PTR_ERR(dphy->phy));
256 		return PTR_ERR(dphy->phy);
257 	}
258 
259 	phy_set_drvdata(dphy->phy, dphy);
260 	provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
261 	if (IS_ERR(provider)) {
262 		dev_err(dev, "Failed to register PHY provider: %ld\n",
263 			PTR_ERR(provider));
264 		return PTR_ERR(provider);
265 	}
266 
267 	return 0;
268 }
269 
270 static const struct of_device_id cdns_dphy_rx_of_match[] = {
271 	{ .compatible = "cdns,dphy-rx" },
272 	{ /* sentinel */ },
273 };
274 MODULE_DEVICE_TABLE(of, cdns_dphy_rx_of_match);
275 
276 static struct platform_driver cdns_dphy_rx_platform_driver = {
277 	.probe		= cdns_dphy_rx_probe,
278 	.driver		= {
279 		.name		= "cdns-mipi-dphy-rx",
280 		.of_match_table	= cdns_dphy_rx_of_match,
281 	},
282 };
283 module_platform_driver(cdns_dphy_rx_platform_driver);
284 
285 MODULE_AUTHOR("Pratyush Yadav <p.yadav@ti.com>");
286 MODULE_DESCRIPTION("Cadence D-PHY Rx Driver");
287 MODULE_LICENSE("GPL");
288