1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright 2021 NXP
4 */
5
6 #include <linux/bitfield.h>
7 #include <linux/clk.h>
8 #include <linux/delay.h>
9 #include <linux/io.h>
10 #include <linux/iopoll.h>
11 #include <linux/mfd/syscon.h>
12 #include <linux/mfd/syscon/imx7-iomuxc-gpr.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/phy/phy.h>
16 #include <linux/platform_device.h>
17 #include <linux/regmap.h>
18 #include <linux/reset.h>
19
20 #include <dt-bindings/phy/phy-imx8-pcie.h>
21
22 #define IMX8MM_PCIE_PHY_CMN_REG061 0x184
23 #define ANA_PLL_CLK_OUT_TO_EXT_IO_EN BIT(0)
24 #define IMX8MM_PCIE_PHY_CMN_REG062 0x188
25 #define ANA_PLL_CLK_OUT_TO_EXT_IO_SEL BIT(3)
26 #define IMX8MM_PCIE_PHY_CMN_REG063 0x18C
27 #define AUX_PLL_REFCLK_SEL_SYS_PLL GENMASK(7, 6)
28 #define IMX8MM_PCIE_PHY_CMN_REG064 0x190
29 #define ANA_AUX_RX_TX_SEL_TX BIT(7)
30 #define ANA_AUX_RX_TERM_GND_EN BIT(3)
31 #define ANA_AUX_TX_TERM BIT(2)
32 #define IMX8MM_PCIE_PHY_CMN_REG065 0x194
33 #define ANA_AUX_RX_TERM (BIT(7) | BIT(4))
34 #define ANA_AUX_TX_LVL GENMASK(3, 0)
35 #define IMX8MM_PCIE_PHY_CMN_REG075 0x1D4
36 #define ANA_PLL_DONE 0x3
37 #define PCIE_PHY_TRSV_REG5 0x414
38 #define PCIE_PHY_TRSV_REG6 0x418
39
40 #define IMX8MM_GPR_PCIE_REF_CLK_SEL GENMASK(25, 24)
41 #define IMX8MM_GPR_PCIE_REF_CLK_PLL FIELD_PREP(IMX8MM_GPR_PCIE_REF_CLK_SEL, 0x3)
42 #define IMX8MM_GPR_PCIE_REF_CLK_EXT FIELD_PREP(IMX8MM_GPR_PCIE_REF_CLK_SEL, 0x2)
43 #define IMX8MM_GPR_PCIE_AUX_EN BIT(19)
44 #define IMX8MM_GPR_PCIE_CMN_RST BIT(18)
45 #define IMX8MM_GPR_PCIE_POWER_OFF BIT(17)
46 #define IMX8MM_GPR_PCIE_SSC_EN BIT(16)
47 #define IMX8MM_GPR_PCIE_AUX_EN_OVERRIDE BIT(9)
48
49 enum imx8_pcie_phy_type {
50 IMX8MM,
51 IMX8MP,
52 };
53
54 struct imx8_pcie_phy_drvdata {
55 const char *gpr;
56 enum imx8_pcie_phy_type variant;
57 };
58
59 struct imx8_pcie_phy {
60 void __iomem *base;
61 struct clk *clk;
62 struct phy *phy;
63 struct regmap *iomuxc_gpr;
64 struct reset_control *perst;
65 struct reset_control *reset;
66 u32 refclk_pad_mode;
67 u32 tx_deemph_gen1;
68 u32 tx_deemph_gen2;
69 bool clkreq_unused;
70 const struct imx8_pcie_phy_drvdata *drvdata;
71 };
72
imx8_pcie_phy_power_on(struct phy * phy)73 static int imx8_pcie_phy_power_on(struct phy *phy)
74 {
75 int ret;
76 u32 val, pad_mode;
77 struct imx8_pcie_phy *imx8_phy = phy_get_drvdata(phy);
78
79 pad_mode = imx8_phy->refclk_pad_mode;
80 switch (imx8_phy->drvdata->variant) {
81 case IMX8MM:
82 reset_control_assert(imx8_phy->reset);
83
84 /* Tune PHY de-emphasis setting to pass PCIe compliance. */
85 if (imx8_phy->tx_deemph_gen1)
86 writel(imx8_phy->tx_deemph_gen1,
87 imx8_phy->base + PCIE_PHY_TRSV_REG5);
88 if (imx8_phy->tx_deemph_gen2)
89 writel(imx8_phy->tx_deemph_gen2,
90 imx8_phy->base + PCIE_PHY_TRSV_REG6);
91 break;
92 case IMX8MP: /* Do nothing. */
93 break;
94 }
95
96 if (pad_mode == IMX8_PCIE_REFCLK_PAD_INPUT ||
97 pad_mode == IMX8_PCIE_REFCLK_PAD_UNUSED) {
98 /* Configure the pad as input */
99 val = readl(imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG061);
100 writel(val & ~ANA_PLL_CLK_OUT_TO_EXT_IO_EN,
101 imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG061);
102 } else {
103 /* Configure the PHY to output the refclock via pad */
104 writel(ANA_PLL_CLK_OUT_TO_EXT_IO_EN,
105 imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG061);
106 }
107
108 if (pad_mode == IMX8_PCIE_REFCLK_PAD_OUTPUT ||
109 pad_mode == IMX8_PCIE_REFCLK_PAD_UNUSED) {
110 /* Source clock from SoC internal PLL */
111 writel(ANA_PLL_CLK_OUT_TO_EXT_IO_SEL,
112 imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG062);
113 if (imx8_phy->drvdata->variant != IMX8MM) {
114 writel(AUX_PLL_REFCLK_SEL_SYS_PLL,
115 imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG063);
116 }
117 val = ANA_AUX_RX_TX_SEL_TX | ANA_AUX_TX_TERM;
118 writel(val | ANA_AUX_RX_TERM_GND_EN,
119 imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG064);
120 writel(ANA_AUX_RX_TERM | ANA_AUX_TX_LVL,
121 imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG065);
122 }
123
124 /* Set AUX_EN_OVERRIDE 1'b0, when the CLKREQ# isn't hooked */
125 regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
126 IMX8MM_GPR_PCIE_AUX_EN_OVERRIDE,
127 imx8_phy->clkreq_unused ?
128 0 : IMX8MM_GPR_PCIE_AUX_EN_OVERRIDE);
129 regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
130 IMX8MM_GPR_PCIE_AUX_EN,
131 IMX8MM_GPR_PCIE_AUX_EN);
132 regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
133 IMX8MM_GPR_PCIE_POWER_OFF, 0);
134 regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
135 IMX8MM_GPR_PCIE_SSC_EN, 0);
136
137 regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
138 IMX8MM_GPR_PCIE_REF_CLK_SEL,
139 pad_mode == IMX8_PCIE_REFCLK_PAD_INPUT ?
140 IMX8MM_GPR_PCIE_REF_CLK_EXT :
141 IMX8MM_GPR_PCIE_REF_CLK_PLL);
142 usleep_range(100, 200);
143
144 /* Do the PHY common block reset */
145 regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
146 IMX8MM_GPR_PCIE_CMN_RST,
147 IMX8MM_GPR_PCIE_CMN_RST);
148
149 switch (imx8_phy->drvdata->variant) {
150 case IMX8MP:
151 reset_control_deassert(imx8_phy->perst);
152 fallthrough;
153 case IMX8MM:
154 reset_control_deassert(imx8_phy->reset);
155 usleep_range(200, 500);
156 break;
157 }
158
159 /* Polling to check the phy is ready or not. */
160 ret = readl_poll_timeout(imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG075,
161 val, val == ANA_PLL_DONE, 10, 20000);
162 return ret;
163 }
164
imx8_pcie_phy_init(struct phy * phy)165 static int imx8_pcie_phy_init(struct phy *phy)
166 {
167 struct imx8_pcie_phy *imx8_phy = phy_get_drvdata(phy);
168
169 return clk_prepare_enable(imx8_phy->clk);
170 }
171
imx8_pcie_phy_exit(struct phy * phy)172 static int imx8_pcie_phy_exit(struct phy *phy)
173 {
174 struct imx8_pcie_phy *imx8_phy = phy_get_drvdata(phy);
175
176 clk_disable_unprepare(imx8_phy->clk);
177
178 return 0;
179 }
180
181 static const struct phy_ops imx8_pcie_phy_ops = {
182 .init = imx8_pcie_phy_init,
183 .exit = imx8_pcie_phy_exit,
184 .power_on = imx8_pcie_phy_power_on,
185 .owner = THIS_MODULE,
186 };
187
188 static const struct imx8_pcie_phy_drvdata imx8mm_drvdata = {
189 .gpr = "fsl,imx8mm-iomuxc-gpr",
190 .variant = IMX8MM,
191 };
192
193 static const struct imx8_pcie_phy_drvdata imx8mp_drvdata = {
194 .gpr = "fsl,imx8mp-iomuxc-gpr",
195 .variant = IMX8MP,
196 };
197
198 static const struct of_device_id imx8_pcie_phy_of_match[] = {
199 {.compatible = "fsl,imx8mm-pcie-phy", .data = &imx8mm_drvdata, },
200 {.compatible = "fsl,imx8mp-pcie-phy", .data = &imx8mp_drvdata, },
201 { },
202 };
203 MODULE_DEVICE_TABLE(of, imx8_pcie_phy_of_match);
204
imx8_pcie_phy_probe(struct platform_device * pdev)205 static int imx8_pcie_phy_probe(struct platform_device *pdev)
206 {
207 struct phy_provider *phy_provider;
208 struct device *dev = &pdev->dev;
209 struct device_node *np = dev->of_node;
210 struct imx8_pcie_phy *imx8_phy;
211
212 imx8_phy = devm_kzalloc(dev, sizeof(*imx8_phy), GFP_KERNEL);
213 if (!imx8_phy)
214 return -ENOMEM;
215
216 imx8_phy->drvdata = of_device_get_match_data(dev);
217
218 /* get PHY refclk pad mode */
219 of_property_read_u32(np, "fsl,refclk-pad-mode",
220 &imx8_phy->refclk_pad_mode);
221
222 if (of_property_read_u32(np, "fsl,tx-deemph-gen1",
223 &imx8_phy->tx_deemph_gen1))
224 imx8_phy->tx_deemph_gen1 = 0;
225
226 if (of_property_read_u32(np, "fsl,tx-deemph-gen2",
227 &imx8_phy->tx_deemph_gen2))
228 imx8_phy->tx_deemph_gen2 = 0;
229
230 if (of_property_read_bool(np, "fsl,clkreq-unsupported"))
231 imx8_phy->clkreq_unused = true;
232 else
233 imx8_phy->clkreq_unused = false;
234
235 imx8_phy->clk = devm_clk_get(dev, "ref");
236 if (IS_ERR(imx8_phy->clk)) {
237 dev_err(dev, "failed to get imx pcie phy clock\n");
238 return PTR_ERR(imx8_phy->clk);
239 }
240
241 /* Grab GPR config register range */
242 imx8_phy->iomuxc_gpr =
243 syscon_regmap_lookup_by_compatible(imx8_phy->drvdata->gpr);
244 if (IS_ERR(imx8_phy->iomuxc_gpr)) {
245 dev_err(dev, "unable to find iomuxc registers\n");
246 return PTR_ERR(imx8_phy->iomuxc_gpr);
247 }
248
249 imx8_phy->reset = devm_reset_control_get_exclusive(dev, "pciephy");
250 if (IS_ERR(imx8_phy->reset)) {
251 dev_err(dev, "Failed to get PCIEPHY reset control\n");
252 return PTR_ERR(imx8_phy->reset);
253 }
254
255 if (imx8_phy->drvdata->variant == IMX8MP) {
256 imx8_phy->perst =
257 devm_reset_control_get_exclusive(dev, "perst");
258 if (IS_ERR(imx8_phy->perst))
259 return dev_err_probe(dev, PTR_ERR(imx8_phy->perst),
260 "Failed to get PCIE PHY PERST control\n");
261 }
262
263 imx8_phy->base = devm_platform_ioremap_resource(pdev, 0);
264 if (IS_ERR(imx8_phy->base))
265 return PTR_ERR(imx8_phy->base);
266
267 imx8_phy->phy = devm_phy_create(dev, NULL, &imx8_pcie_phy_ops);
268 if (IS_ERR(imx8_phy->phy))
269 return PTR_ERR(imx8_phy->phy);
270
271 phy_set_drvdata(imx8_phy->phy, imx8_phy);
272
273 phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
274
275 return PTR_ERR_OR_ZERO(phy_provider);
276 }
277
278 static struct platform_driver imx8_pcie_phy_driver = {
279 .probe = imx8_pcie_phy_probe,
280 .driver = {
281 .name = "imx8-pcie-phy",
282 .of_match_table = imx8_pcie_phy_of_match,
283 }
284 };
285 module_platform_driver(imx8_pcie_phy_driver);
286
287 MODULE_DESCRIPTION("FSL IMX8 PCIE PHY driver");
288 MODULE_LICENSE("GPL v2");
289