1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Samsung SATA SerDes(PHY) driver
4 *
5 * Copyright (C) 2013 Samsung Electronics Co., Ltd.
6 * Authors: Girish K S <ks.giri@samsung.com>
7 * Yuvaraj Kumar C D <yuvaraj.cd@samsung.com>
8 */
9
10 #include <linux/clk.h>
11 #include <linux/delay.h>
12 #include <linux/io.h>
13 #include <linux/i2c.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/of_address.h>
18 #include <linux/phy/phy.h>
19 #include <linux/platform_device.h>
20 #include <linux/regmap.h>
21 #include <linux/spinlock.h>
22 #include <linux/mfd/syscon.h>
23
24 #define SATAPHY_CONTROL_OFFSET 0x0724
25 #define EXYNOS5_SATAPHY_PMU_ENABLE BIT(0)
26 #define EXYNOS5_SATA_RESET 0x4
27 #define RESET_GLOBAL_RST_N BIT(0)
28 #define RESET_CMN_RST_N BIT(1)
29 #define RESET_CMN_BLOCK_RST_N BIT(2)
30 #define RESET_CMN_I2C_RST_N BIT(3)
31 #define RESET_TX_RX_PIPE_RST_N BIT(4)
32 #define RESET_TX_RX_BLOCK_RST_N BIT(5)
33 #define RESET_TX_RX_I2C_RST_N (BIT(6) | BIT(7))
34 #define LINK_RESET 0xf0000
35 #define EXYNOS5_SATA_MODE0 0x10
36 #define SATA_SPD_GEN3 BIT(1)
37 #define EXYNOS5_SATA_CTRL0 0x14
38 #define CTRL0_P0_PHY_CALIBRATED_SEL BIT(9)
39 #define CTRL0_P0_PHY_CALIBRATED BIT(8)
40 #define EXYNOS5_SATA_PHSATA_CTRLM 0xe0
41 #define PHCTRLM_REF_RATE BIT(1)
42 #define PHCTRLM_HIGH_SPEED BIT(0)
43 #define EXYNOS5_SATA_PHSATA_STATM 0xf0
44 #define PHSTATM_PLL_LOCKED BIT(0)
45
46 #define PHY_PLL_TIMEOUT (usecs_to_jiffies(1000))
47
48 struct exynos_sata_phy {
49 struct phy *phy;
50 struct clk *phyclk;
51 void __iomem *regs;
52 struct regmap *pmureg;
53 struct i2c_client *client;
54 };
55
wait_for_reg_status(void __iomem * base,u32 reg,u32 checkbit,u32 status)56 static int wait_for_reg_status(void __iomem *base, u32 reg, u32 checkbit,
57 u32 status)
58 {
59 unsigned long timeout = jiffies + PHY_PLL_TIMEOUT;
60
61 while (time_before(jiffies, timeout)) {
62 if ((readl(base + reg) & checkbit) == status)
63 return 0;
64 }
65
66 return -EFAULT;
67 }
68
exynos_sata_phy_power_on(struct phy * phy)69 static int exynos_sata_phy_power_on(struct phy *phy)
70 {
71 struct exynos_sata_phy *sata_phy = phy_get_drvdata(phy);
72
73 return regmap_update_bits(sata_phy->pmureg, SATAPHY_CONTROL_OFFSET,
74 EXYNOS5_SATAPHY_PMU_ENABLE, true);
75
76 }
77
exynos_sata_phy_power_off(struct phy * phy)78 static int exynos_sata_phy_power_off(struct phy *phy)
79 {
80 struct exynos_sata_phy *sata_phy = phy_get_drvdata(phy);
81
82 return regmap_update_bits(sata_phy->pmureg, SATAPHY_CONTROL_OFFSET,
83 EXYNOS5_SATAPHY_PMU_ENABLE, false);
84
85 }
86
exynos_sata_phy_init(struct phy * phy)87 static int exynos_sata_phy_init(struct phy *phy)
88 {
89 u32 val = 0;
90 int ret = 0;
91 u8 buf[] = { 0x3a, 0x0b };
92 struct exynos_sata_phy *sata_phy = phy_get_drvdata(phy);
93
94 ret = regmap_update_bits(sata_phy->pmureg, SATAPHY_CONTROL_OFFSET,
95 EXYNOS5_SATAPHY_PMU_ENABLE, true);
96 if (ret != 0)
97 dev_err(&sata_phy->phy->dev, "phy init failed\n");
98
99 writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
100
101 val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
102 val |= RESET_GLOBAL_RST_N | RESET_CMN_RST_N | RESET_CMN_BLOCK_RST_N
103 | RESET_CMN_I2C_RST_N | RESET_TX_RX_PIPE_RST_N
104 | RESET_TX_RX_BLOCK_RST_N | RESET_TX_RX_I2C_RST_N;
105 writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
106
107 val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
108 val |= LINK_RESET;
109 writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
110
111 val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
112 val |= RESET_CMN_RST_N;
113 writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
114
115 val = readl(sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
116 val &= ~PHCTRLM_REF_RATE;
117 writel(val, sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
118
119 /* High speed enable for Gen3 */
120 val = readl(sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
121 val |= PHCTRLM_HIGH_SPEED;
122 writel(val, sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
123
124 val = readl(sata_phy->regs + EXYNOS5_SATA_CTRL0);
125 val |= CTRL0_P0_PHY_CALIBRATED_SEL | CTRL0_P0_PHY_CALIBRATED;
126 writel(val, sata_phy->regs + EXYNOS5_SATA_CTRL0);
127
128 val = readl(sata_phy->regs + EXYNOS5_SATA_MODE0);
129 val |= SATA_SPD_GEN3;
130 writel(val, sata_phy->regs + EXYNOS5_SATA_MODE0);
131
132 ret = i2c_master_send(sata_phy->client, buf, sizeof(buf));
133 if (ret < 0)
134 return ret;
135
136 /* release cmu reset */
137 val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
138 val &= ~RESET_CMN_RST_N;
139 writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
140
141 val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
142 val |= RESET_CMN_RST_N;
143 writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
144
145 ret = wait_for_reg_status(sata_phy->regs,
146 EXYNOS5_SATA_PHSATA_STATM,
147 PHSTATM_PLL_LOCKED, 1);
148 if (ret < 0)
149 dev_err(&sata_phy->phy->dev,
150 "PHY PLL locking failed\n");
151 return ret;
152 }
153
154 static const struct phy_ops exynos_sata_phy_ops = {
155 .init = exynos_sata_phy_init,
156 .power_on = exynos_sata_phy_power_on,
157 .power_off = exynos_sata_phy_power_off,
158 .owner = THIS_MODULE,
159 };
160
exynos_sata_phy_probe(struct platform_device * pdev)161 static int exynos_sata_phy_probe(struct platform_device *pdev)
162 {
163 struct exynos_sata_phy *sata_phy;
164 struct device *dev = &pdev->dev;
165 struct phy_provider *phy_provider;
166 struct device_node *node;
167 int ret = 0;
168
169 sata_phy = devm_kzalloc(dev, sizeof(*sata_phy), GFP_KERNEL);
170 if (!sata_phy)
171 return -ENOMEM;
172
173 sata_phy->regs = devm_platform_ioremap_resource(pdev, 0);
174 if (IS_ERR(sata_phy->regs))
175 return PTR_ERR(sata_phy->regs);
176
177 sata_phy->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
178 "samsung,syscon-phandle");
179 if (IS_ERR(sata_phy->pmureg)) {
180 dev_err(dev, "syscon regmap lookup failed.\n");
181 return PTR_ERR(sata_phy->pmureg);
182 }
183
184 node = of_parse_phandle(dev->of_node,
185 "samsung,exynos-sataphy-i2c-phandle", 0);
186 if (!node)
187 return -EINVAL;
188
189 sata_phy->client = of_find_i2c_device_by_node(node);
190 of_node_put(node);
191 if (!sata_phy->client)
192 return -EPROBE_DEFER;
193
194 dev_set_drvdata(dev, sata_phy);
195
196 sata_phy->phyclk = devm_clk_get(dev, "sata_phyctrl");
197 if (IS_ERR(sata_phy->phyclk)) {
198 dev_err(dev, "failed to get clk for PHY\n");
199 ret = PTR_ERR(sata_phy->phyclk);
200 goto put_dev;
201 }
202
203 ret = clk_prepare_enable(sata_phy->phyclk);
204 if (ret < 0) {
205 dev_err(dev, "failed to enable source clk\n");
206 goto put_dev;
207 }
208
209 sata_phy->phy = devm_phy_create(dev, NULL, &exynos_sata_phy_ops);
210 if (IS_ERR(sata_phy->phy)) {
211 dev_err(dev, "failed to create PHY\n");
212 ret = PTR_ERR(sata_phy->phy);
213 goto clk_disable;
214 }
215
216 phy_set_drvdata(sata_phy->phy, sata_phy);
217
218 phy_provider = devm_of_phy_provider_register(dev,
219 of_phy_simple_xlate);
220 if (IS_ERR(phy_provider)) {
221 ret = PTR_ERR(phy_provider);
222 goto clk_disable;
223 }
224
225 return 0;
226
227 clk_disable:
228 clk_disable_unprepare(sata_phy->phyclk);
229 put_dev:
230 put_device(&sata_phy->client->dev);
231
232 return ret;
233 }
234
235 static const struct of_device_id exynos_sata_phy_of_match[] = {
236 { .compatible = "samsung,exynos5250-sata-phy" },
237 { },
238 };
239 MODULE_DEVICE_TABLE(of, exynos_sata_phy_of_match);
240
241 static struct platform_driver exynos_sata_phy_driver = {
242 .probe = exynos_sata_phy_probe,
243 .driver = {
244 .of_match_table = exynos_sata_phy_of_match,
245 .name = "samsung,sata-phy",
246 .suppress_bind_attrs = true,
247 }
248 };
249 module_platform_driver(exynos_sata_phy_driver);
250
251 MODULE_DESCRIPTION("Samsung SerDes PHY driver");
252 MODULE_LICENSE("GPL v2");
253 MODULE_AUTHOR("Girish K S <ks.giri@samsung.com>");
254 MODULE_AUTHOR("Yuvaraj C D <yuvaraj.cd@samsung.com>");
255