1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2022 MediaTek Inc.
4 * Author: Jianjun Wang <jianjun.wang@mediatek.com>
5 */
6
7 #include <linux/bitfield.h>
8 #include <linux/module.h>
9 #include <linux/nvmem-consumer.h>
10 #include <linux/of.h>
11 #include <linux/phy/phy.h>
12 #include <linux/platform_device.h>
13 #include <linux/slab.h>
14
15 #include "phy-mtk-io.h"
16
17 #define PEXTP_ANA_GLB_00_REG 0x9000
18 /* Internal Resistor Selection of TX Bias Current */
19 #define EFUSE_GLB_INTR_SEL GENMASK(28, 24)
20
21 #define PEXTP_ANA_LN0_TRX_REG 0xa000
22
23 #define PEXTP_ANA_TX_REG 0x04
24 /* TX PMOS impedance selection */
25 #define EFUSE_LN_TX_PMOS_SEL GENMASK(5, 2)
26 /* TX NMOS impedance selection */
27 #define EFUSE_LN_TX_NMOS_SEL GENMASK(11, 8)
28
29 #define PEXTP_ANA_RX_REG 0x3c
30 /* RX impedance selection */
31 #define EFUSE_LN_RX_SEL GENMASK(3, 0)
32
33 #define PEXTP_ANA_LANE_OFFSET 0x100
34
35 /**
36 * struct mtk_pcie_lane_efuse - eFuse data for each lane
37 * @tx_pmos: TX PMOS impedance selection data
38 * @tx_nmos: TX NMOS impedance selection data
39 * @rx_data: RX impedance selection data
40 * @lane_efuse_supported: software eFuse data is supported for this lane
41 */
42 struct mtk_pcie_lane_efuse {
43 u32 tx_pmos;
44 u32 tx_nmos;
45 u32 rx_data;
46 bool lane_efuse_supported;
47 };
48
49 /**
50 * struct mtk_pcie_phy_data - phy data for each SoC
51 * @num_lanes: supported lane numbers
52 * @sw_efuse_supported: support software to load eFuse data
53 */
54 struct mtk_pcie_phy_data {
55 int num_lanes;
56 bool sw_efuse_supported;
57 };
58
59 /**
60 * struct mtk_pcie_phy - PCIe phy driver main structure
61 * @dev: pointer to device
62 * @phy: pointer to generic phy
63 * @sif_base: IO mapped register base address of system interface
64 * @data: pointer to SoC dependent data
65 * @sw_efuse_en: software eFuse enable status
66 * @efuse_glb_intr: internal resistor selection of TX bias current data
67 * @efuse: pointer to eFuse data for each lane
68 */
69 struct mtk_pcie_phy {
70 struct device *dev;
71 struct phy *phy;
72 void __iomem *sif_base;
73 const struct mtk_pcie_phy_data *data;
74
75 bool sw_efuse_en;
76 u32 efuse_glb_intr;
77 struct mtk_pcie_lane_efuse *efuse;
78 };
79
mtk_pcie_efuse_set_lane(struct mtk_pcie_phy * pcie_phy,unsigned int lane)80 static void mtk_pcie_efuse_set_lane(struct mtk_pcie_phy *pcie_phy,
81 unsigned int lane)
82 {
83 struct mtk_pcie_lane_efuse *data = &pcie_phy->efuse[lane];
84 void __iomem *addr;
85
86 if (!data->lane_efuse_supported)
87 return;
88
89 addr = pcie_phy->sif_base + PEXTP_ANA_LN0_TRX_REG +
90 lane * PEXTP_ANA_LANE_OFFSET;
91
92 mtk_phy_update_field(addr + PEXTP_ANA_TX_REG, EFUSE_LN_TX_PMOS_SEL,
93 data->tx_pmos);
94
95 mtk_phy_update_field(addr + PEXTP_ANA_TX_REG, EFUSE_LN_TX_NMOS_SEL,
96 data->tx_nmos);
97
98 mtk_phy_update_field(addr + PEXTP_ANA_RX_REG, EFUSE_LN_RX_SEL,
99 data->rx_data);
100 }
101
102 /**
103 * mtk_pcie_phy_init() - Initialize the phy
104 * @phy: the phy to be initialized
105 *
106 * Initialize the phy by setting the efuse data.
107 * The hardware settings will be reset during suspend, it should be
108 * reinitialized when the consumer calls phy_init() again on resume.
109 */
mtk_pcie_phy_init(struct phy * phy)110 static int mtk_pcie_phy_init(struct phy *phy)
111 {
112 struct mtk_pcie_phy *pcie_phy = phy_get_drvdata(phy);
113 int i;
114
115 if (!pcie_phy->sw_efuse_en)
116 return 0;
117
118 /* Set global data */
119 mtk_phy_update_field(pcie_phy->sif_base + PEXTP_ANA_GLB_00_REG,
120 EFUSE_GLB_INTR_SEL, pcie_phy->efuse_glb_intr);
121
122 for (i = 0; i < pcie_phy->data->num_lanes; i++)
123 mtk_pcie_efuse_set_lane(pcie_phy, i);
124
125 return 0;
126 }
127
128 static const struct phy_ops mtk_pcie_phy_ops = {
129 .init = mtk_pcie_phy_init,
130 .owner = THIS_MODULE,
131 };
132
mtk_pcie_efuse_read_for_lane(struct mtk_pcie_phy * pcie_phy,unsigned int lane)133 static int mtk_pcie_efuse_read_for_lane(struct mtk_pcie_phy *pcie_phy,
134 unsigned int lane)
135 {
136 struct mtk_pcie_lane_efuse *efuse = &pcie_phy->efuse[lane];
137 struct device *dev = pcie_phy->dev;
138 char efuse_id[16];
139 int ret;
140
141 snprintf(efuse_id, sizeof(efuse_id), "tx_ln%d_pmos", lane);
142 ret = nvmem_cell_read_variable_le_u32(dev, efuse_id, &efuse->tx_pmos);
143 if (ret)
144 return dev_err_probe(dev, ret, "Failed to read %s\n", efuse_id);
145
146 snprintf(efuse_id, sizeof(efuse_id), "tx_ln%d_nmos", lane);
147 ret = nvmem_cell_read_variable_le_u32(dev, efuse_id, &efuse->tx_nmos);
148 if (ret)
149 return dev_err_probe(dev, ret, "Failed to read %s\n", efuse_id);
150
151 snprintf(efuse_id, sizeof(efuse_id), "rx_ln%d", lane);
152 ret = nvmem_cell_read_variable_le_u32(dev, efuse_id, &efuse->rx_data);
153 if (ret)
154 return dev_err_probe(dev, ret, "Failed to read %s\n", efuse_id);
155
156 if (!(efuse->tx_pmos || efuse->tx_nmos || efuse->rx_data))
157 return dev_err_probe(dev, -EINVAL,
158 "No eFuse data found for lane%d, but dts enable it\n",
159 lane);
160
161 efuse->lane_efuse_supported = true;
162
163 return 0;
164 }
165
mtk_pcie_read_efuse(struct mtk_pcie_phy * pcie_phy)166 static int mtk_pcie_read_efuse(struct mtk_pcie_phy *pcie_phy)
167 {
168 struct device *dev = pcie_phy->dev;
169 bool nvmem_enabled;
170 int ret, i;
171
172 /* nvmem data is optional */
173 nvmem_enabled = device_property_present(dev, "nvmem-cells");
174 if (!nvmem_enabled)
175 return 0;
176
177 ret = nvmem_cell_read_variable_le_u32(dev, "glb_intr",
178 &pcie_phy->efuse_glb_intr);
179 if (ret)
180 return dev_err_probe(dev, ret, "Failed to read glb_intr\n");
181
182 pcie_phy->sw_efuse_en = true;
183
184 pcie_phy->efuse = devm_kzalloc(dev, pcie_phy->data->num_lanes *
185 sizeof(*pcie_phy->efuse), GFP_KERNEL);
186 if (!pcie_phy->efuse)
187 return -ENOMEM;
188
189 for (i = 0; i < pcie_phy->data->num_lanes; i++) {
190 ret = mtk_pcie_efuse_read_for_lane(pcie_phy, i);
191 if (ret)
192 return ret;
193 }
194
195 return 0;
196 }
197
mtk_pcie_phy_probe(struct platform_device * pdev)198 static int mtk_pcie_phy_probe(struct platform_device *pdev)
199 {
200 struct device *dev = &pdev->dev;
201 struct phy_provider *provider;
202 struct mtk_pcie_phy *pcie_phy;
203 int ret;
204
205 pcie_phy = devm_kzalloc(dev, sizeof(*pcie_phy), GFP_KERNEL);
206 if (!pcie_phy)
207 return -ENOMEM;
208
209 pcie_phy->sif_base = devm_platform_ioremap_resource_byname(pdev, "sif");
210 if (IS_ERR(pcie_phy->sif_base))
211 return dev_err_probe(dev, PTR_ERR(pcie_phy->sif_base),
212 "Failed to map phy-sif base\n");
213
214 pcie_phy->phy = devm_phy_create(dev, dev->of_node, &mtk_pcie_phy_ops);
215 if (IS_ERR(pcie_phy->phy))
216 return dev_err_probe(dev, PTR_ERR(pcie_phy->phy),
217 "Failed to create PCIe phy\n");
218
219 pcie_phy->dev = dev;
220 pcie_phy->data = of_device_get_match_data(dev);
221 if (!pcie_phy->data)
222 return dev_err_probe(dev, -EINVAL, "Failed to get phy data\n");
223
224 if (pcie_phy->data->sw_efuse_supported) {
225 /*
226 * Failed to read the efuse data is not a fatal problem,
227 * ignore the failure and keep going.
228 */
229 ret = mtk_pcie_read_efuse(pcie_phy);
230 if (ret == -EPROBE_DEFER || ret == -ENOMEM)
231 return ret;
232 }
233
234 phy_set_drvdata(pcie_phy->phy, pcie_phy);
235
236 provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
237 if (IS_ERR(provider))
238 return dev_err_probe(dev, PTR_ERR(provider),
239 "PCIe phy probe failed\n");
240
241 return 0;
242 }
243
244 static const struct mtk_pcie_phy_data mt8195_data = {
245 .num_lanes = 2,
246 .sw_efuse_supported = true,
247 };
248
249 static const struct of_device_id mtk_pcie_phy_of_match[] = {
250 { .compatible = "mediatek,mt8195-pcie-phy", .data = &mt8195_data },
251 { },
252 };
253 MODULE_DEVICE_TABLE(of, mtk_pcie_phy_of_match);
254
255 static struct platform_driver mtk_pcie_phy_driver = {
256 .probe = mtk_pcie_phy_probe,
257 .driver = {
258 .name = "mtk-pcie-phy",
259 .of_match_table = mtk_pcie_phy_of_match,
260 },
261 };
262 module_platform_driver(mtk_pcie_phy_driver);
263
264 MODULE_DESCRIPTION("MediaTek PCIe PHY driver");
265 MODULE_AUTHOR("Jianjun Wang <jianjun.wang@mediatek.com>");
266 MODULE_LICENSE("GPL");
267