1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2019 Baylibre, SAS.
3 * Author: Jerome Brunet <jbrunet@baylibre.com>
4 */
5
6 #include <linux/bitfield.h>
7 #include <linux/clk.h>
8 #include <linux/clk-provider.h>
9 #include <linux/device.h>
10 #include <linux/io.h>
11 #include <linux/iopoll.h>
12 #include <linux/mdio-mux.h>
13 #include <linux/module.h>
14 #include <linux/phy.h>
15 #include <linux/platform_device.h>
16
17 #define ETH_PLL_STS 0x40
18 #define ETH_PLL_CTL0 0x44
19 #define PLL_CTL0_LOCK_DIG BIT(30)
20 #define PLL_CTL0_RST BIT(29)
21 #define PLL_CTL0_EN BIT(28)
22 #define PLL_CTL0_SEL BIT(23)
23 #define PLL_CTL0_N GENMASK(14, 10)
24 #define PLL_CTL0_M GENMASK(8, 0)
25 #define PLL_LOCK_TIMEOUT 1000000
26 #define PLL_MUX_NUM_PARENT 2
27 #define ETH_PLL_CTL1 0x48
28 #define ETH_PLL_CTL2 0x4c
29 #define ETH_PLL_CTL3 0x50
30 #define ETH_PLL_CTL4 0x54
31 #define ETH_PLL_CTL5 0x58
32 #define ETH_PLL_CTL6 0x5c
33 #define ETH_PLL_CTL7 0x60
34
35 #define ETH_PHY_CNTL0 0x80
36 #define EPHY_G12A_ID 0x33010180
37 #define ETH_PHY_CNTL1 0x84
38 #define PHY_CNTL1_ST_MODE GENMASK(2, 0)
39 #define PHY_CNTL1_ST_PHYADD GENMASK(7, 3)
40 #define EPHY_DFLT_ADD 8
41 #define PHY_CNTL1_MII_MODE GENMASK(15, 14)
42 #define EPHY_MODE_RMII 0x1
43 #define PHY_CNTL1_CLK_EN BIT(16)
44 #define PHY_CNTL1_CLKFREQ BIT(17)
45 #define PHY_CNTL1_PHY_ENB BIT(18)
46 #define ETH_PHY_CNTL2 0x88
47 #define PHY_CNTL2_USE_INTERNAL BIT(5)
48 #define PHY_CNTL2_SMI_SRC_MAC BIT(6)
49 #define PHY_CNTL2_RX_CLK_EPHY BIT(9)
50
51 #define MESON_G12A_MDIO_EXTERNAL_ID 0
52 #define MESON_G12A_MDIO_INTERNAL_ID 1
53
54 struct g12a_mdio_mux {
55 bool pll_is_enabled;
56 void __iomem *regs;
57 void *mux_handle;
58 struct clk *pclk;
59 struct clk *pll;
60 };
61
62 struct g12a_ephy_pll {
63 void __iomem *base;
64 struct clk_hw hw;
65 };
66
67 #define g12a_ephy_pll_to_dev(_hw) \
68 container_of(_hw, struct g12a_ephy_pll, hw)
69
g12a_ephy_pll_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)70 static unsigned long g12a_ephy_pll_recalc_rate(struct clk_hw *hw,
71 unsigned long parent_rate)
72 {
73 struct g12a_ephy_pll *pll = g12a_ephy_pll_to_dev(hw);
74 u32 val, m, n;
75
76 val = readl(pll->base + ETH_PLL_CTL0);
77 m = FIELD_GET(PLL_CTL0_M, val);
78 n = FIELD_GET(PLL_CTL0_N, val);
79
80 return parent_rate * m / n;
81 }
82
g12a_ephy_pll_enable(struct clk_hw * hw)83 static int g12a_ephy_pll_enable(struct clk_hw *hw)
84 {
85 struct g12a_ephy_pll *pll = g12a_ephy_pll_to_dev(hw);
86 u32 val = readl(pll->base + ETH_PLL_CTL0);
87
88 /* Apply both enable an reset */
89 val |= PLL_CTL0_RST | PLL_CTL0_EN;
90 writel(val, pll->base + ETH_PLL_CTL0);
91
92 /* Clear the reset to let PLL lock */
93 val &= ~PLL_CTL0_RST;
94 writel(val, pll->base + ETH_PLL_CTL0);
95
96 /* Poll on the digital lock instead of the usual analog lock
97 * This is done because bit 31 is unreliable on some SoC. Bit
98 * 31 may indicate that the PLL is not lock eventhough the clock
99 * is actually running
100 */
101 return readl_poll_timeout(pll->base + ETH_PLL_CTL0, val,
102 val & PLL_CTL0_LOCK_DIG, 0, PLL_LOCK_TIMEOUT);
103 }
104
g12a_ephy_pll_disable(struct clk_hw * hw)105 static void g12a_ephy_pll_disable(struct clk_hw *hw)
106 {
107 struct g12a_ephy_pll *pll = g12a_ephy_pll_to_dev(hw);
108 u32 val;
109
110 val = readl(pll->base + ETH_PLL_CTL0);
111 val &= ~PLL_CTL0_EN;
112 val |= PLL_CTL0_RST;
113 writel(val, pll->base + ETH_PLL_CTL0);
114 }
115
g12a_ephy_pll_is_enabled(struct clk_hw * hw)116 static int g12a_ephy_pll_is_enabled(struct clk_hw *hw)
117 {
118 struct g12a_ephy_pll *pll = g12a_ephy_pll_to_dev(hw);
119 unsigned int val;
120
121 val = readl(pll->base + ETH_PLL_CTL0);
122
123 return (val & PLL_CTL0_LOCK_DIG) ? 1 : 0;
124 }
125
g12a_ephy_pll_init(struct clk_hw * hw)126 static void g12a_ephy_pll_init(struct clk_hw *hw)
127 {
128 struct g12a_ephy_pll *pll = g12a_ephy_pll_to_dev(hw);
129
130 /* Apply PLL HW settings */
131 writel(0x29c0040a, pll->base + ETH_PLL_CTL0);
132 writel(0x927e0000, pll->base + ETH_PLL_CTL1);
133 writel(0xac5f49e5, pll->base + ETH_PLL_CTL2);
134 writel(0x00000000, pll->base + ETH_PLL_CTL3);
135 writel(0x00000000, pll->base + ETH_PLL_CTL4);
136 writel(0x20200000, pll->base + ETH_PLL_CTL5);
137 writel(0x0000c002, pll->base + ETH_PLL_CTL6);
138 writel(0x00000023, pll->base + ETH_PLL_CTL7);
139 }
140
141 static const struct clk_ops g12a_ephy_pll_ops = {
142 .recalc_rate = g12a_ephy_pll_recalc_rate,
143 .is_enabled = g12a_ephy_pll_is_enabled,
144 .enable = g12a_ephy_pll_enable,
145 .disable = g12a_ephy_pll_disable,
146 .init = g12a_ephy_pll_init,
147 };
148
g12a_enable_internal_mdio(struct g12a_mdio_mux * priv)149 static int g12a_enable_internal_mdio(struct g12a_mdio_mux *priv)
150 {
151 int ret;
152
153 /* Enable the phy clock */
154 if (!priv->pll_is_enabled) {
155 ret = clk_prepare_enable(priv->pll);
156 if (ret)
157 return ret;
158 }
159
160 priv->pll_is_enabled = true;
161
162 /* Initialize ephy control */
163 writel(EPHY_G12A_ID, priv->regs + ETH_PHY_CNTL0);
164 writel(FIELD_PREP(PHY_CNTL1_ST_MODE, 3) |
165 FIELD_PREP(PHY_CNTL1_ST_PHYADD, EPHY_DFLT_ADD) |
166 FIELD_PREP(PHY_CNTL1_MII_MODE, EPHY_MODE_RMII) |
167 PHY_CNTL1_CLK_EN |
168 PHY_CNTL1_CLKFREQ |
169 PHY_CNTL1_PHY_ENB,
170 priv->regs + ETH_PHY_CNTL1);
171 writel(PHY_CNTL2_USE_INTERNAL |
172 PHY_CNTL2_SMI_SRC_MAC |
173 PHY_CNTL2_RX_CLK_EPHY,
174 priv->regs + ETH_PHY_CNTL2);
175
176 return 0;
177 }
178
g12a_enable_external_mdio(struct g12a_mdio_mux * priv)179 static int g12a_enable_external_mdio(struct g12a_mdio_mux *priv)
180 {
181 /* Reset the mdio bus mux */
182 writel_relaxed(0x0, priv->regs + ETH_PHY_CNTL2);
183
184 /* Disable the phy clock if enabled */
185 if (priv->pll_is_enabled) {
186 clk_disable_unprepare(priv->pll);
187 priv->pll_is_enabled = false;
188 }
189
190 return 0;
191 }
192
g12a_mdio_switch_fn(int current_child,int desired_child,void * data)193 static int g12a_mdio_switch_fn(int current_child, int desired_child,
194 void *data)
195 {
196 struct g12a_mdio_mux *priv = dev_get_drvdata(data);
197
198 if (current_child == desired_child)
199 return 0;
200
201 switch (desired_child) {
202 case MESON_G12A_MDIO_EXTERNAL_ID:
203 return g12a_enable_external_mdio(priv);
204 case MESON_G12A_MDIO_INTERNAL_ID:
205 return g12a_enable_internal_mdio(priv);
206 default:
207 return -EINVAL;
208 }
209 }
210
211 static const struct of_device_id g12a_mdio_mux_match[] = {
212 { .compatible = "amlogic,g12a-mdio-mux", },
213 {},
214 };
215 MODULE_DEVICE_TABLE(of, g12a_mdio_mux_match);
216
g12a_ephy_glue_clk_register(struct device * dev)217 static int g12a_ephy_glue_clk_register(struct device *dev)
218 {
219 struct g12a_mdio_mux *priv = dev_get_drvdata(dev);
220 const char *parent_names[PLL_MUX_NUM_PARENT];
221 struct clk_init_data init;
222 struct g12a_ephy_pll *pll;
223 struct clk_mux *mux;
224 struct clk *clk;
225 char *name;
226 int i;
227
228 /* get the mux parents */
229 for (i = 0; i < PLL_MUX_NUM_PARENT; i++) {
230 char in_name[8];
231
232 snprintf(in_name, sizeof(in_name), "clkin%d", i);
233 clk = devm_clk_get(dev, in_name);
234 if (IS_ERR(clk)) {
235 if (PTR_ERR(clk) != -EPROBE_DEFER)
236 dev_err(dev, "Missing clock %s\n", in_name);
237 return PTR_ERR(clk);
238 }
239
240 parent_names[i] = __clk_get_name(clk);
241 }
242
243 /* create the input mux */
244 mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
245 if (!mux)
246 return -ENOMEM;
247
248 name = kasprintf(GFP_KERNEL, "%s#mux", dev_name(dev));
249 if (!name)
250 return -ENOMEM;
251
252 init.name = name;
253 init.ops = &clk_mux_ro_ops;
254 init.flags = 0;
255 init.parent_names = parent_names;
256 init.num_parents = PLL_MUX_NUM_PARENT;
257
258 mux->reg = priv->regs + ETH_PLL_CTL0;
259 mux->shift = __ffs(PLL_CTL0_SEL);
260 mux->mask = PLL_CTL0_SEL >> mux->shift;
261 mux->hw.init = &init;
262
263 clk = devm_clk_register(dev, &mux->hw);
264 kfree(name);
265 if (IS_ERR(clk)) {
266 dev_err(dev, "failed to register input mux\n");
267 return PTR_ERR(clk);
268 }
269
270 /* create the pll */
271 pll = devm_kzalloc(dev, sizeof(*pll), GFP_KERNEL);
272 if (!pll)
273 return -ENOMEM;
274
275 name = kasprintf(GFP_KERNEL, "%s#pll", dev_name(dev));
276 if (!name)
277 return -ENOMEM;
278
279 init.name = name;
280 init.ops = &g12a_ephy_pll_ops;
281 init.flags = 0;
282 parent_names[0] = __clk_get_name(clk);
283 init.parent_names = parent_names;
284 init.num_parents = 1;
285
286 pll->base = priv->regs;
287 pll->hw.init = &init;
288
289 clk = devm_clk_register(dev, &pll->hw);
290 kfree(name);
291 if (IS_ERR(clk)) {
292 dev_err(dev, "failed to register input mux\n");
293 return PTR_ERR(clk);
294 }
295
296 priv->pll = clk;
297
298 return 0;
299 }
300
g12a_mdio_mux_probe(struct platform_device * pdev)301 static int g12a_mdio_mux_probe(struct platform_device *pdev)
302 {
303 struct device *dev = &pdev->dev;
304 struct g12a_mdio_mux *priv;
305 int ret;
306
307 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
308 if (!priv)
309 return -ENOMEM;
310
311 platform_set_drvdata(pdev, priv);
312
313 priv->regs = devm_platform_ioremap_resource(pdev, 0);
314 if (IS_ERR(priv->regs))
315 return PTR_ERR(priv->regs);
316
317 priv->pclk = devm_clk_get(dev, "pclk");
318 if (IS_ERR(priv->pclk)) {
319 ret = PTR_ERR(priv->pclk);
320 if (ret != -EPROBE_DEFER)
321 dev_err(dev, "failed to get peripheral clock\n");
322 return ret;
323 }
324
325 /* Make sure the device registers are clocked */
326 ret = clk_prepare_enable(priv->pclk);
327 if (ret) {
328 dev_err(dev, "failed to enable peripheral clock");
329 return ret;
330 }
331
332 /* Register PLL in CCF */
333 ret = g12a_ephy_glue_clk_register(dev);
334 if (ret)
335 goto err;
336
337 ret = mdio_mux_init(dev, dev->of_node, g12a_mdio_switch_fn,
338 &priv->mux_handle, dev, NULL);
339 if (ret) {
340 if (ret != -EPROBE_DEFER)
341 dev_err(dev, "mdio multiplexer init failed: %d", ret);
342 goto err;
343 }
344
345 return 0;
346
347 err:
348 clk_disable_unprepare(priv->pclk);
349 return ret;
350 }
351
g12a_mdio_mux_remove(struct platform_device * pdev)352 static int g12a_mdio_mux_remove(struct platform_device *pdev)
353 {
354 struct g12a_mdio_mux *priv = platform_get_drvdata(pdev);
355
356 mdio_mux_uninit(priv->mux_handle);
357
358 if (priv->pll_is_enabled)
359 clk_disable_unprepare(priv->pll);
360
361 clk_disable_unprepare(priv->pclk);
362
363 return 0;
364 }
365
366 static struct platform_driver g12a_mdio_mux_driver = {
367 .probe = g12a_mdio_mux_probe,
368 .remove = g12a_mdio_mux_remove,
369 .driver = {
370 .name = "g12a-mdio_mux",
371 .of_match_table = g12a_mdio_mux_match,
372 },
373 };
374 module_platform_driver(g12a_mdio_mux_driver);
375
376 MODULE_DESCRIPTION("Amlogic G12a MDIO multiplexer driver");
377 MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
378 MODULE_LICENSE("GPL v2");
379
