1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Mediatek MT7621 PCI PHY Driver
4 * Author: Sergio Paracuellos <sergio.paracuellos@gmail.com>
5 */
6
7 #include <dt-bindings/phy/phy.h>
8 #include <linux/clk.h>
9 #include <linux/bitfield.h>
10 #include <linux/bitops.h>
11 #include <linux/module.h>
12 #include <linux/of_address.h>
13 #include <linux/of_device.h>
14 #include <linux/phy/phy.h>
15 #include <linux/platform_device.h>
16 #include <linux/regmap.h>
17 #include <linux/sys_soc.h>
18
19 #define RG_PE1_PIPE_REG 0x02c
20 #define RG_PE1_PIPE_RST BIT(12)
21 #define RG_PE1_PIPE_CMD_FRC BIT(4)
22
23 #define RG_P0_TO_P1_WIDTH 0x100
24 #define RG_PE1_H_LCDDS_REG 0x49c
25 #define RG_PE1_H_LCDDS_PCW GENMASK(30, 0)
26
27 #define RG_PE1_FRC_H_XTAL_REG 0x400
28 #define RG_PE1_FRC_H_XTAL_TYPE BIT(8)
29 #define RG_PE1_H_XTAL_TYPE GENMASK(10, 9)
30
31 #define RG_PE1_FRC_PHY_REG 0x000
32 #define RG_PE1_FRC_PHY_EN BIT(4)
33 #define RG_PE1_PHY_EN BIT(5)
34
35 #define RG_PE1_H_PLL_REG 0x490
36 #define RG_PE1_H_PLL_BC GENMASK(23, 22)
37 #define RG_PE1_H_PLL_BP GENMASK(21, 18)
38 #define RG_PE1_H_PLL_IR GENMASK(15, 12)
39 #define RG_PE1_H_PLL_IC GENMASK(11, 8)
40 #define RG_PE1_H_PLL_PREDIV GENMASK(7, 6)
41 #define RG_PE1_PLL_DIVEN GENMASK(3, 1)
42
43 #define RG_PE1_H_PLL_FBKSEL_REG 0x4bc
44 #define RG_PE1_H_PLL_FBKSEL GENMASK(5, 4)
45
46 #define RG_PE1_H_LCDDS_SSC_PRD_REG 0x4a4
47 #define RG_PE1_H_LCDDS_SSC_PRD GENMASK(15, 0)
48
49 #define RG_PE1_H_LCDDS_SSC_DELTA_REG 0x4a8
50 #define RG_PE1_H_LCDDS_SSC_DELTA GENMASK(11, 0)
51 #define RG_PE1_H_LCDDS_SSC_DELTA1 GENMASK(27, 16)
52
53 #define RG_PE1_LCDDS_CLK_PH_INV_REG 0x4a0
54 #define RG_PE1_LCDDS_CLK_PH_INV BIT(5)
55
56 #define RG_PE1_H_PLL_BR_REG 0x4ac
57 #define RG_PE1_H_PLL_BR GENMASK(18, 16)
58
59 #define RG_PE1_MSTCKDIV_REG 0x414
60 #define RG_PE1_MSTCKDIV GENMASK(7, 6)
61
62 #define RG_PE1_FRC_MSTCKDIV BIT(5)
63
64 #define MAX_PHYS 2
65
66 /**
67 * struct mt7621_pci_phy - Mt7621 Pcie PHY core
68 * @dev: pointer to device
69 * @regmap: kernel regmap pointer
70 * @phy: pointer to the kernel PHY device
71 * @sys_clk: pointer to the system XTAL clock
72 * @port_base: base register
73 * @has_dual_port: if the phy has dual ports.
74 * @bypass_pipe_rst: mark if 'mt7621_bypass_pipe_rst'
75 * needs to be executed. Depends on chip revision.
76 */
77 struct mt7621_pci_phy {
78 struct device *dev;
79 struct regmap *regmap;
80 struct phy *phy;
81 struct clk *sys_clk;
82 void __iomem *port_base;
83 bool has_dual_port;
84 bool bypass_pipe_rst;
85 };
86
mt7621_phy_rmw(struct mt7621_pci_phy * phy,u32 reg,u32 clr,u32 set)87 static inline void mt7621_phy_rmw(struct mt7621_pci_phy *phy,
88 u32 reg, u32 clr, u32 set)
89 {
90 u32 val;
91
92 /*
93 * We cannot use 'regmap_write_bits' here because internally
94 * 'set' is masked before is set to the value that will be
95 * written to the register. That way results in no reliable
96 * pci setup. Avoid to mask 'set' before set value to 'val'
97 * completely avoid the problem.
98 */
99 regmap_read(phy->regmap, reg, &val);
100 val &= ~clr;
101 val |= set;
102 regmap_write(phy->regmap, reg, val);
103 }
104
mt7621_bypass_pipe_rst(struct mt7621_pci_phy * phy)105 static void mt7621_bypass_pipe_rst(struct mt7621_pci_phy *phy)
106 {
107 mt7621_phy_rmw(phy, RG_PE1_PIPE_REG, 0, RG_PE1_PIPE_RST);
108 mt7621_phy_rmw(phy, RG_PE1_PIPE_REG, 0, RG_PE1_PIPE_CMD_FRC);
109
110 if (phy->has_dual_port) {
111 mt7621_phy_rmw(phy, RG_PE1_PIPE_REG + RG_P0_TO_P1_WIDTH,
112 0, RG_PE1_PIPE_RST);
113 mt7621_phy_rmw(phy, RG_PE1_PIPE_REG + RG_P0_TO_P1_WIDTH,
114 0, RG_PE1_PIPE_CMD_FRC);
115 }
116 }
117
mt7621_set_phy_for_ssc(struct mt7621_pci_phy * phy)118 static int mt7621_set_phy_for_ssc(struct mt7621_pci_phy *phy)
119 {
120 struct device *dev = phy->dev;
121 unsigned long clk_rate;
122
123 clk_rate = clk_get_rate(phy->sys_clk);
124 if (!clk_rate)
125 return -EINVAL;
126
127 /* Set PCIe Port PHY to disable SSC */
128 /* Debug Xtal Type */
129 mt7621_phy_rmw(phy, RG_PE1_FRC_H_XTAL_REG,
130 RG_PE1_FRC_H_XTAL_TYPE | RG_PE1_H_XTAL_TYPE,
131 RG_PE1_FRC_H_XTAL_TYPE |
132 FIELD_PREP(RG_PE1_H_XTAL_TYPE, 0x00));
133
134 /* disable port */
135 mt7621_phy_rmw(phy, RG_PE1_FRC_PHY_REG, RG_PE1_PHY_EN,
136 RG_PE1_FRC_PHY_EN);
137
138 if (phy->has_dual_port) {
139 mt7621_phy_rmw(phy, RG_PE1_FRC_PHY_REG + RG_P0_TO_P1_WIDTH,
140 RG_PE1_PHY_EN, RG_PE1_FRC_PHY_EN);
141 }
142
143 if (clk_rate == 40000000) { /* 40MHz Xtal */
144 /* Set Pre-divider ratio (for host mode) */
145 mt7621_phy_rmw(phy, RG_PE1_H_PLL_REG, RG_PE1_H_PLL_PREDIV,
146 FIELD_PREP(RG_PE1_H_PLL_PREDIV, 0x01));
147
148 dev_dbg(dev, "Xtal is 40MHz\n");
149 } else if (clk_rate == 25000000) { /* 25MHz Xal */
150 mt7621_phy_rmw(phy, RG_PE1_H_PLL_REG, RG_PE1_H_PLL_PREDIV,
151 FIELD_PREP(RG_PE1_H_PLL_PREDIV, 0x00));
152
153 /* Select feedback clock */
154 mt7621_phy_rmw(phy, RG_PE1_H_PLL_FBKSEL_REG,
155 RG_PE1_H_PLL_FBKSEL,
156 FIELD_PREP(RG_PE1_H_PLL_FBKSEL, 0x01));
157
158 /* DDS NCPO PCW (for host mode) */
159 mt7621_phy_rmw(phy, RG_PE1_H_LCDDS_SSC_PRD_REG,
160 RG_PE1_H_LCDDS_SSC_PRD,
161 FIELD_PREP(RG_PE1_H_LCDDS_SSC_PRD, 0x00));
162
163 /* DDS SSC dither period control */
164 mt7621_phy_rmw(phy, RG_PE1_H_LCDDS_SSC_PRD_REG,
165 RG_PE1_H_LCDDS_SSC_PRD,
166 FIELD_PREP(RG_PE1_H_LCDDS_SSC_PRD, 0x18d));
167
168 /* DDS SSC dither amplitude control */
169 mt7621_phy_rmw(phy, RG_PE1_H_LCDDS_SSC_DELTA_REG,
170 RG_PE1_H_LCDDS_SSC_DELTA |
171 RG_PE1_H_LCDDS_SSC_DELTA1,
172 FIELD_PREP(RG_PE1_H_LCDDS_SSC_DELTA, 0x4a) |
173 FIELD_PREP(RG_PE1_H_LCDDS_SSC_DELTA1, 0x4a));
174
175 dev_dbg(dev, "Xtal is 25MHz\n");
176 } else { /* 20MHz Xtal */
177 mt7621_phy_rmw(phy, RG_PE1_H_PLL_REG, RG_PE1_H_PLL_PREDIV,
178 FIELD_PREP(RG_PE1_H_PLL_PREDIV, 0x00));
179
180 dev_dbg(dev, "Xtal is 20MHz\n");
181 }
182
183 /* DDS clock inversion */
184 mt7621_phy_rmw(phy, RG_PE1_LCDDS_CLK_PH_INV_REG,
185 RG_PE1_LCDDS_CLK_PH_INV, RG_PE1_LCDDS_CLK_PH_INV);
186
187 /* Set PLL bits */
188 mt7621_phy_rmw(phy, RG_PE1_H_PLL_REG,
189 RG_PE1_H_PLL_BC | RG_PE1_H_PLL_BP | RG_PE1_H_PLL_IR |
190 RG_PE1_H_PLL_IC | RG_PE1_PLL_DIVEN,
191 FIELD_PREP(RG_PE1_H_PLL_BC, 0x02) |
192 FIELD_PREP(RG_PE1_H_PLL_BP, 0x06) |
193 FIELD_PREP(RG_PE1_H_PLL_IR, 0x02) |
194 FIELD_PREP(RG_PE1_H_PLL_IC, 0x01) |
195 FIELD_PREP(RG_PE1_PLL_DIVEN, 0x02));
196
197 mt7621_phy_rmw(phy, RG_PE1_H_PLL_BR_REG, RG_PE1_H_PLL_BR,
198 FIELD_PREP(RG_PE1_H_PLL_BR, 0x00));
199
200 if (clk_rate == 40000000) { /* 40MHz Xtal */
201 /* set force mode enable of da_pe1_mstckdiv */
202 mt7621_phy_rmw(phy, RG_PE1_MSTCKDIV_REG,
203 RG_PE1_MSTCKDIV | RG_PE1_FRC_MSTCKDIV,
204 FIELD_PREP(RG_PE1_MSTCKDIV, 0x01) |
205 RG_PE1_FRC_MSTCKDIV);
206 }
207
208 return 0;
209 }
210
mt7621_pci_phy_init(struct phy * phy)211 static int mt7621_pci_phy_init(struct phy *phy)
212 {
213 struct mt7621_pci_phy *mphy = phy_get_drvdata(phy);
214
215 if (mphy->bypass_pipe_rst)
216 mt7621_bypass_pipe_rst(mphy);
217
218 return mt7621_set_phy_for_ssc(mphy);
219 }
220
mt7621_pci_phy_power_on(struct phy * phy)221 static int mt7621_pci_phy_power_on(struct phy *phy)
222 {
223 struct mt7621_pci_phy *mphy = phy_get_drvdata(phy);
224
225 /* Enable PHY and disable force mode */
226 mt7621_phy_rmw(mphy, RG_PE1_FRC_PHY_REG,
227 RG_PE1_FRC_PHY_EN, RG_PE1_PHY_EN);
228
229 if (mphy->has_dual_port) {
230 mt7621_phy_rmw(mphy, RG_PE1_FRC_PHY_REG + RG_P0_TO_P1_WIDTH,
231 RG_PE1_FRC_PHY_EN, RG_PE1_PHY_EN);
232 }
233
234 return 0;
235 }
236
mt7621_pci_phy_power_off(struct phy * phy)237 static int mt7621_pci_phy_power_off(struct phy *phy)
238 {
239 struct mt7621_pci_phy *mphy = phy_get_drvdata(phy);
240
241 /* Disable PHY */
242 mt7621_phy_rmw(mphy, RG_PE1_FRC_PHY_REG,
243 RG_PE1_PHY_EN, RG_PE1_FRC_PHY_EN);
244
245 if (mphy->has_dual_port) {
246 mt7621_phy_rmw(mphy, RG_PE1_FRC_PHY_REG + RG_P0_TO_P1_WIDTH,
247 RG_PE1_PHY_EN, RG_PE1_FRC_PHY_EN);
248 }
249
250 return 0;
251 }
252
mt7621_pci_phy_exit(struct phy * phy)253 static int mt7621_pci_phy_exit(struct phy *phy)
254 {
255 return 0;
256 }
257
258 static const struct phy_ops mt7621_pci_phy_ops = {
259 .init = mt7621_pci_phy_init,
260 .exit = mt7621_pci_phy_exit,
261 .power_on = mt7621_pci_phy_power_on,
262 .power_off = mt7621_pci_phy_power_off,
263 .owner = THIS_MODULE,
264 };
265
mt7621_pcie_phy_of_xlate(struct device * dev,struct of_phandle_args * args)266 static struct phy *mt7621_pcie_phy_of_xlate(struct device *dev,
267 struct of_phandle_args *args)
268 {
269 struct mt7621_pci_phy *mt7621_phy = dev_get_drvdata(dev);
270
271 if (WARN_ON(args->args[0] >= MAX_PHYS))
272 return ERR_PTR(-ENODEV);
273
274 mt7621_phy->has_dual_port = args->args[0];
275
276 dev_dbg(dev, "PHY for 0x%px (dual port = %d)\n",
277 mt7621_phy->port_base, mt7621_phy->has_dual_port);
278
279 return mt7621_phy->phy;
280 }
281
282 static const struct soc_device_attribute mt7621_pci_quirks_match[] = {
283 { .soc_id = "mt7621", .revision = "E2" },
284 { /* sentinel */ }
285 };
286
287 static const struct regmap_config mt7621_pci_phy_regmap_config = {
288 .reg_bits = 32,
289 .val_bits = 32,
290 .reg_stride = 4,
291 .max_register = 0x700,
292 };
293
mt7621_pci_phy_probe(struct platform_device * pdev)294 static int mt7621_pci_phy_probe(struct platform_device *pdev)
295 {
296 struct device *dev = &pdev->dev;
297 const struct soc_device_attribute *attr;
298 struct phy_provider *provider;
299 struct mt7621_pci_phy *phy;
300
301 phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
302 if (!phy)
303 return -ENOMEM;
304
305 attr = soc_device_match(mt7621_pci_quirks_match);
306 if (attr)
307 phy->bypass_pipe_rst = true;
308
309 phy->dev = dev;
310 platform_set_drvdata(pdev, phy);
311
312 phy->port_base = devm_platform_ioremap_resource(pdev, 0);
313 if (IS_ERR(phy->port_base)) {
314 dev_err(dev, "failed to remap phy regs\n");
315 return PTR_ERR(phy->port_base);
316 }
317
318 phy->regmap = devm_regmap_init_mmio(phy->dev, phy->port_base,
319 &mt7621_pci_phy_regmap_config);
320 if (IS_ERR(phy->regmap))
321 return PTR_ERR(phy->regmap);
322
323 phy->phy = devm_phy_create(dev, dev->of_node, &mt7621_pci_phy_ops);
324 if (IS_ERR(phy->phy)) {
325 dev_err(dev, "failed to create phy\n");
326 return PTR_ERR(phy->phy);
327 }
328
329 phy->sys_clk = devm_clk_get(dev, NULL);
330 if (IS_ERR(phy->sys_clk)) {
331 dev_err(dev, "failed to get phy clock\n");
332 return PTR_ERR(phy->sys_clk);
333 }
334
335 phy_set_drvdata(phy->phy, phy);
336
337 provider = devm_of_phy_provider_register(dev, mt7621_pcie_phy_of_xlate);
338
339 return PTR_ERR_OR_ZERO(provider);
340 }
341
342 static const struct of_device_id mt7621_pci_phy_ids[] = {
343 { .compatible = "mediatek,mt7621-pci-phy" },
344 {},
345 };
346 MODULE_DEVICE_TABLE(of, mt7621_pci_phy_ids);
347
348 static struct platform_driver mt7621_pci_phy_driver = {
349 .probe = mt7621_pci_phy_probe,
350 .driver = {
351 .name = "mt7621-pci-phy",
352 .of_match_table = mt7621_pci_phy_ids,
353 },
354 };
355
356 builtin_platform_driver(mt7621_pci_phy_driver);
357
358 MODULE_AUTHOR("Sergio Paracuellos <sergio.paracuellos@gmail.com>");
359 MODULE_DESCRIPTION("MediaTek MT7621 PCIe PHY driver");
360 MODULE_LICENSE("GPL v2");
361