xref: /linux/drivers/clk/clk-lan966x.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Microchip LAN966x SoC Clock driver.
4  *
5  * Copyright (C) 2021 Microchip Technology, Inc. and its subsidiaries
6  *
7  * Author: Kavyasree Kotagiri <kavyasree.kotagiri@microchip.com>
8  */
9 
10 #include <linux/bitfield.h>
11 #include <linux/clk-provider.h>
12 #include <linux/io.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/platform_device.h>
17 #include <linux/slab.h>
18 
19 #include <dt-bindings/clock/microchip,lan966x.h>
20 
21 #define GCK_ENA         BIT(0)
22 #define GCK_SRC_SEL     GENMASK(9, 8)
23 #define GCK_PRESCALER   GENMASK(23, 16)
24 
25 #define DIV_MAX		255
26 
27 static const char * const lan966x_clk_names[] = {
28 	"qspi0", "qspi1", "qspi2", "sdmmc0",
29 	"pi", "mcan0", "mcan1", "flexcom0",
30 	"flexcom1", "flexcom2", "flexcom3",
31 	"flexcom4", "timer1", "usb_refclk",
32 };
33 
34 static const char * const lan969x_clk_names[] = {
35 	"qspi0", "qspi2", "sdmmc0", "sdmmc1",
36 	"mcan0", "mcan1", "flexcom0",
37 	"flexcom1", "flexcom2", "flexcom3",
38 	"timer1", "usb_refclk",
39 };
40 
41 struct lan966x_gck {
42 	struct clk_hw hw;
43 	void __iomem *reg;
44 };
45 #define to_lan966x_gck(hw) container_of(hw, struct lan966x_gck, hw)
46 
47 static const struct clk_parent_data lan966x_gck_pdata[] = {
48 	{ .fw_name = "cpu", },
49 	{ .fw_name = "ddr", },
50 	{ .fw_name = "sys", },
51 };
52 
53 static struct clk_init_data init = {
54 	.parent_data = lan966x_gck_pdata,
55 	.num_parents = ARRAY_SIZE(lan966x_gck_pdata),
56 };
57 
58 struct clk_gate_soc_desc {
59 	const char *name;
60 	int bit_idx;
61 };
62 
63 static const struct clk_gate_soc_desc lan966x_clk_gate_desc[] = {
64 	{ "uhphs", 11 },
65 	{ "udphs", 10 },
66 	{ "mcramc", 9 },
67 	{ "hmatrix", 8 },
68 	{ }
69 };
70 
71 static const struct clk_gate_soc_desc lan969x_clk_gate_desc[] = {
72 	{ "usb_drd", 10 },
73 	{ "mcramc", 9 },
74 	{ "hmatrix", 8 },
75 	{ }
76 };
77 
78 struct lan966x_match_data {
79 	char *name;
80 	const char * const *clk_name;
81 	const struct clk_gate_soc_desc *clk_gate_desc;
82 	u8 num_generic_clks;
83 	u8 num_total_clks;
84 };
85 
86 static struct lan966x_match_data lan966x_desc = {
87 	.name = "lan966x",
88 	.clk_name = lan966x_clk_names,
89 	.clk_gate_desc = lan966x_clk_gate_desc,
90 	.num_total_clks = 18,
91 	.num_generic_clks = 14,
92 };
93 
94 static struct lan966x_match_data lan969x_desc = {
95 	.name = "lan969x",
96 	.clk_name = lan969x_clk_names,
97 	.clk_gate_desc = lan969x_clk_gate_desc,
98 	.num_total_clks = 15,
99 	.num_generic_clks = 12,
100 };
101 
102 static DEFINE_SPINLOCK(clk_gate_lock);
103 static void __iomem *base;
104 
105 static int lan966x_gck_enable(struct clk_hw *hw)
106 {
107 	struct lan966x_gck *gck = to_lan966x_gck(hw);
108 	u32 val = readl(gck->reg);
109 
110 	val |= GCK_ENA;
111 	writel(val, gck->reg);
112 
113 	return 0;
114 }
115 
116 static void lan966x_gck_disable(struct clk_hw *hw)
117 {
118 	struct lan966x_gck *gck = to_lan966x_gck(hw);
119 	u32 val = readl(gck->reg);
120 
121 	val &= ~GCK_ENA;
122 	writel(val, gck->reg);
123 }
124 
125 static int lan966x_gck_set_rate(struct clk_hw *hw,
126 				unsigned long rate,
127 				unsigned long parent_rate)
128 {
129 	struct lan966x_gck *gck = to_lan966x_gck(hw);
130 	u32 div, val = readl(gck->reg);
131 
132 	if (rate == 0 || parent_rate == 0)
133 		return -EINVAL;
134 
135 	/* Set Prescalar */
136 	div = parent_rate / rate;
137 	val &= ~GCK_PRESCALER;
138 	val |= FIELD_PREP(GCK_PRESCALER, (div - 1));
139 	writel(val, gck->reg);
140 
141 	return 0;
142 }
143 
144 static unsigned long lan966x_gck_recalc_rate(struct clk_hw *hw,
145 					     unsigned long parent_rate)
146 {
147 	struct lan966x_gck *gck = to_lan966x_gck(hw);
148 	u32 div, val = readl(gck->reg);
149 
150 	div = FIELD_GET(GCK_PRESCALER, val);
151 
152 	return parent_rate / (div + 1);
153 }
154 
155 static int lan966x_gck_determine_rate(struct clk_hw *hw,
156 				      struct clk_rate_request *req)
157 {
158 	struct clk_hw *parent;
159 	int i;
160 
161 	for (i = 0; i < clk_hw_get_num_parents(hw); ++i) {
162 		parent = clk_hw_get_parent_by_index(hw, i);
163 		if (!parent)
164 			continue;
165 
166 		/* Allowed prescaler divider range is 0-255 */
167 		if (clk_hw_get_rate(parent) / req->rate <= DIV_MAX) {
168 			req->best_parent_hw = parent;
169 			req->best_parent_rate = clk_hw_get_rate(parent);
170 
171 			return 0;
172 		}
173 	}
174 
175 	return -EINVAL;
176 }
177 
178 static u8 lan966x_gck_get_parent(struct clk_hw *hw)
179 {
180 	struct lan966x_gck *gck = to_lan966x_gck(hw);
181 	u32 val = readl(gck->reg);
182 
183 	return FIELD_GET(GCK_SRC_SEL, val);
184 }
185 
186 static int lan966x_gck_set_parent(struct clk_hw *hw, u8 index)
187 {
188 	struct lan966x_gck *gck = to_lan966x_gck(hw);
189 	u32 val = readl(gck->reg);
190 
191 	val &= ~GCK_SRC_SEL;
192 	val |= FIELD_PREP(GCK_SRC_SEL, index);
193 	writel(val, gck->reg);
194 
195 	return 0;
196 }
197 
198 static const struct clk_ops lan966x_gck_ops = {
199 	.enable         = lan966x_gck_enable,
200 	.disable        = lan966x_gck_disable,
201 	.set_rate       = lan966x_gck_set_rate,
202 	.recalc_rate    = lan966x_gck_recalc_rate,
203 	.determine_rate = lan966x_gck_determine_rate,
204 	.set_parent     = lan966x_gck_set_parent,
205 	.get_parent     = lan966x_gck_get_parent,
206 };
207 
208 static struct clk_hw *lan966x_gck_clk_register(struct device *dev, int i)
209 {
210 	struct lan966x_gck *priv;
211 	int ret;
212 
213 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
214 	if (!priv)
215 		return ERR_PTR(-ENOMEM);
216 
217 	priv->reg = base + (i * 4);
218 	priv->hw.init = &init;
219 	ret = devm_clk_hw_register(dev, &priv->hw);
220 	if (ret)
221 		return ERR_PTR(ret);
222 
223 	return &priv->hw;
224 };
225 
226 static int lan966x_gate_clk_register(struct device *dev,
227 				     const struct lan966x_match_data *data,
228 				     struct clk_hw_onecell_data *hw_data,
229 				     void __iomem *gate_base)
230 {
231 	for (int i = data->num_generic_clks; i < data->num_total_clks; ++i) {
232 		int idx = i - data->num_generic_clks;
233 		const struct clk_gate_soc_desc *desc;
234 
235 		desc = &data->clk_gate_desc[idx];
236 
237 		hw_data->hws[i] =
238 			devm_clk_hw_register_gate(dev, desc->name,
239 						  data->name, 0, gate_base,
240 						  desc->bit_idx,
241 						  0, &clk_gate_lock);
242 
243 		if (IS_ERR(hw_data->hws[i]))
244 			return dev_err_probe(dev, PTR_ERR(hw_data->hws[i]),
245 					     "failed to register %s clock\n",
246 					     desc->name);
247 	}
248 
249 	return 0;
250 }
251 
252 static int lan966x_clk_probe(struct platform_device *pdev)
253 {
254 	const struct lan966x_match_data *data;
255 	struct clk_hw_onecell_data *hw_data;
256 	struct device *dev = &pdev->dev;
257 	void __iomem *gate_base;
258 	struct resource *res;
259 	int i, ret;
260 
261 	data = device_get_match_data(dev);
262 	if (!data)
263 		return -EINVAL;
264 
265 	hw_data = devm_kzalloc(dev, struct_size(hw_data, hws, data->num_total_clks),
266 			       GFP_KERNEL);
267 	if (!hw_data)
268 		return -ENOMEM;
269 
270 	base = devm_platform_ioremap_resource(pdev, 0);
271 	if (IS_ERR(base))
272 		return PTR_ERR(base);
273 
274 	init.ops = &lan966x_gck_ops;
275 
276 	hw_data->num = data->num_generic_clks;
277 
278 	for (i = 0; i < data->num_generic_clks; i++) {
279 		init.name = data->clk_name[i];
280 		hw_data->hws[i] = lan966x_gck_clk_register(dev, i);
281 		if (IS_ERR(hw_data->hws[i])) {
282 			dev_err(dev, "failed to register %s clock\n",
283 				init.name);
284 			return PTR_ERR(hw_data->hws[i]);
285 		}
286 	}
287 
288 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
289 	if (res) {
290 		gate_base = devm_ioremap_resource(&pdev->dev, res);
291 		if (IS_ERR(gate_base))
292 			return PTR_ERR(gate_base);
293 
294 		hw_data->num = data->num_total_clks;
295 
296 		ret = lan966x_gate_clk_register(dev, data, hw_data, gate_base);
297 		if (ret)
298 			return ret;
299 	}
300 
301 	return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, hw_data);
302 }
303 
304 static const struct of_device_id lan966x_clk_dt_ids[] = {
305 	{ .compatible = "microchip,lan966x-gck", .data = &lan966x_desc },
306 	{ .compatible = "microchip,lan9691-gck", .data = &lan969x_desc },
307 	{ }
308 };
309 MODULE_DEVICE_TABLE(of, lan966x_clk_dt_ids);
310 
311 static struct platform_driver lan966x_clk_driver = {
312 	.probe  = lan966x_clk_probe,
313 	.driver = {
314 		.name = "lan966x-clk",
315 		.of_match_table = lan966x_clk_dt_ids,
316 	},
317 };
318 module_platform_driver(lan966x_clk_driver);
319 
320 MODULE_AUTHOR("Kavyasree Kotagiri <kavyasree.kotagiri@microchip.com>");
321 MODULE_DESCRIPTION("LAN966X clock driver");
322 MODULE_LICENSE("GPL v2");
323