xref: /openbmc/linux/drivers/clk/clk-en7523.c (revision 917f5982)
1 // SPDX-License-Identifier: GPL-2.0-only
2 
3 #include <linux/delay.h>
4 #include <linux/clk-provider.h>
5 #include <linux/io.h>
6 #include <linux/of.h>
7 #include <linux/platform_device.h>
8 #include <dt-bindings/clock/en7523-clk.h>
9 
10 #define REG_PCI_CONTROL			0x88
11 #define   REG_PCI_CONTROL_PERSTOUT	BIT(29)
12 #define   REG_PCI_CONTROL_PERSTOUT1	BIT(26)
13 #define   REG_PCI_CONTROL_REFCLK_EN1	BIT(22)
14 #define REG_GSW_CLK_DIV_SEL		0x1b4
15 #define REG_EMI_CLK_DIV_SEL		0x1b8
16 #define REG_BUS_CLK_DIV_SEL		0x1bc
17 #define REG_SPI_CLK_DIV_SEL		0x1c4
18 #define REG_SPI_CLK_FREQ_SEL		0x1c8
19 #define REG_NPU_CLK_DIV_SEL		0x1fc
20 #define REG_CRYPTO_CLKSRC		0x200
21 #define REG_RESET_CONTROL		0x834
22 #define   REG_RESET_CONTROL_PCIEHB	BIT(29)
23 #define   REG_RESET_CONTROL_PCIE1	BIT(27)
24 #define   REG_RESET_CONTROL_PCIE2	BIT(26)
25 
26 struct en_clk_desc {
27 	int id;
28 	const char *name;
29 	u32 base_reg;
30 	u8 base_bits;
31 	u8 base_shift;
32 	union {
33 		const unsigned int *base_values;
34 		unsigned int base_value;
35 	};
36 	size_t n_base_values;
37 
38 	u16 div_reg;
39 	u8 div_bits;
40 	u8 div_shift;
41 	u16 div_val0;
42 	u8 div_step;
43 	u8 div_offset;
44 };
45 
46 struct en_clk_gate {
47 	void __iomem *base;
48 	struct clk_hw hw;
49 };
50 
51 static const u32 gsw_base[] = { 400000000, 500000000 };
52 static const u32 emi_base[] = { 333000000, 400000000 };
53 static const u32 bus_base[] = { 500000000, 540000000 };
54 static const u32 slic_base[] = { 100000000, 3125000 };
55 static const u32 npu_base[] = { 333000000, 400000000, 500000000 };
56 
57 static const struct en_clk_desc en7523_base_clks[] = {
58 	{
59 		.id = EN7523_CLK_GSW,
60 		.name = "gsw",
61 
62 		.base_reg = REG_GSW_CLK_DIV_SEL,
63 		.base_bits = 1,
64 		.base_shift = 8,
65 		.base_values = gsw_base,
66 		.n_base_values = ARRAY_SIZE(gsw_base),
67 
68 		.div_bits = 3,
69 		.div_shift = 0,
70 		.div_step = 1,
71 		.div_offset = 1,
72 	}, {
73 		.id = EN7523_CLK_EMI,
74 		.name = "emi",
75 
76 		.base_reg = REG_EMI_CLK_DIV_SEL,
77 		.base_bits = 1,
78 		.base_shift = 8,
79 		.base_values = emi_base,
80 		.n_base_values = ARRAY_SIZE(emi_base),
81 
82 		.div_bits = 3,
83 		.div_shift = 0,
84 		.div_step = 1,
85 		.div_offset = 1,
86 	}, {
87 		.id = EN7523_CLK_BUS,
88 		.name = "bus",
89 
90 		.base_reg = REG_BUS_CLK_DIV_SEL,
91 		.base_bits = 1,
92 		.base_shift = 8,
93 		.base_values = bus_base,
94 		.n_base_values = ARRAY_SIZE(bus_base),
95 
96 		.div_bits = 3,
97 		.div_shift = 0,
98 		.div_step = 1,
99 		.div_offset = 1,
100 	}, {
101 		.id = EN7523_CLK_SLIC,
102 		.name = "slic",
103 
104 		.base_reg = REG_SPI_CLK_FREQ_SEL,
105 		.base_bits = 1,
106 		.base_shift = 0,
107 		.base_values = slic_base,
108 		.n_base_values = ARRAY_SIZE(slic_base),
109 
110 		.div_reg = REG_SPI_CLK_DIV_SEL,
111 		.div_bits = 5,
112 		.div_shift = 24,
113 		.div_val0 = 20,
114 		.div_step = 2,
115 	}, {
116 		.id = EN7523_CLK_SPI,
117 		.name = "spi",
118 
119 		.base_reg = REG_SPI_CLK_DIV_SEL,
120 
121 		.base_value = 400000000,
122 
123 		.div_bits = 5,
124 		.div_shift = 8,
125 		.div_val0 = 40,
126 		.div_step = 2,
127 	}, {
128 		.id = EN7523_CLK_NPU,
129 		.name = "npu",
130 
131 		.base_reg = REG_NPU_CLK_DIV_SEL,
132 		.base_bits = 2,
133 		.base_shift = 8,
134 		.base_values = npu_base,
135 		.n_base_values = ARRAY_SIZE(npu_base),
136 
137 		.div_bits = 3,
138 		.div_shift = 0,
139 		.div_step = 1,
140 		.div_offset = 1,
141 	}, {
142 		.id = EN7523_CLK_CRYPTO,
143 		.name = "crypto",
144 
145 		.base_reg = REG_CRYPTO_CLKSRC,
146 		.base_bits = 1,
147 		.base_shift = 0,
148 		.base_values = emi_base,
149 		.n_base_values = ARRAY_SIZE(emi_base),
150 	}
151 };
152 
153 static const struct of_device_id of_match_clk_en7523[] = {
154 	{ .compatible = "airoha,en7523-scu", },
155 	{ /* sentinel */ }
156 };
157 
158 static unsigned int en7523_get_base_rate(void __iomem *base, unsigned int i)
159 {
160 	const struct en_clk_desc *desc = &en7523_base_clks[i];
161 	u32 val;
162 
163 	if (!desc->base_bits)
164 		return desc->base_value;
165 
166 	val = readl(base + desc->base_reg);
167 	val >>= desc->base_shift;
168 	val &= (1 << desc->base_bits) - 1;
169 
170 	if (val >= desc->n_base_values)
171 		return 0;
172 
173 	return desc->base_values[val];
174 }
175 
176 static u32 en7523_get_div(void __iomem *base, int i)
177 {
178 	const struct en_clk_desc *desc = &en7523_base_clks[i];
179 	u32 reg, val;
180 
181 	if (!desc->div_bits)
182 		return 1;
183 
184 	reg = desc->div_reg ? desc->div_reg : desc->base_reg;
185 	val = readl(base + reg);
186 	val >>= desc->div_shift;
187 	val &= (1 << desc->div_bits) - 1;
188 
189 	if (!val && desc->div_val0)
190 		return desc->div_val0;
191 
192 	return (val + desc->div_offset) * desc->div_step;
193 }
194 
195 static int en7523_pci_is_enabled(struct clk_hw *hw)
196 {
197 	struct en_clk_gate *cg = container_of(hw, struct en_clk_gate, hw);
198 
199 	return !!(readl(cg->base + REG_PCI_CONTROL) & REG_PCI_CONTROL_REFCLK_EN1);
200 }
201 
202 static int en7523_pci_prepare(struct clk_hw *hw)
203 {
204 	struct en_clk_gate *cg = container_of(hw, struct en_clk_gate, hw);
205 	void __iomem *np_base = cg->base;
206 	u32 val, mask;
207 
208 	/* Need to pull device low before reset */
209 	val = readl(np_base + REG_PCI_CONTROL);
210 	val &= ~(REG_PCI_CONTROL_PERSTOUT1 | REG_PCI_CONTROL_PERSTOUT);
211 	writel(val, np_base + REG_PCI_CONTROL);
212 	usleep_range(1000, 2000);
213 
214 	/* Enable PCIe port 1 */
215 	val |= REG_PCI_CONTROL_REFCLK_EN1;
216 	writel(val, np_base + REG_PCI_CONTROL);
217 	usleep_range(1000, 2000);
218 
219 	/* Reset to default */
220 	val = readl(np_base + REG_RESET_CONTROL);
221 	mask = REG_RESET_CONTROL_PCIE1 | REG_RESET_CONTROL_PCIE2 |
222 	       REG_RESET_CONTROL_PCIEHB;
223 	writel(val & ~mask, np_base + REG_RESET_CONTROL);
224 	usleep_range(1000, 2000);
225 	writel(val | mask, np_base + REG_RESET_CONTROL);
226 	msleep(100);
227 	writel(val & ~mask, np_base + REG_RESET_CONTROL);
228 	usleep_range(5000, 10000);
229 
230 	/* Release device */
231 	mask = REG_PCI_CONTROL_PERSTOUT1 | REG_PCI_CONTROL_PERSTOUT;
232 	val = readl(np_base + REG_PCI_CONTROL);
233 	writel(val & ~mask, np_base + REG_PCI_CONTROL);
234 	usleep_range(1000, 2000);
235 	writel(val | mask, np_base + REG_PCI_CONTROL);
236 	msleep(250);
237 
238 	return 0;
239 }
240 
241 static void en7523_pci_unprepare(struct clk_hw *hw)
242 {
243 	struct en_clk_gate *cg = container_of(hw, struct en_clk_gate, hw);
244 	void __iomem *np_base = cg->base;
245 	u32 val;
246 
247 	val = readl(np_base + REG_PCI_CONTROL);
248 	val &= ~REG_PCI_CONTROL_REFCLK_EN1;
249 	writel(val, np_base + REG_PCI_CONTROL);
250 }
251 
252 static struct clk_hw *en7523_register_pcie_clk(struct device *dev,
253 					       void __iomem *np_base)
254 {
255 	static const struct clk_ops pcie_gate_ops = {
256 		.is_enabled = en7523_pci_is_enabled,
257 		.prepare = en7523_pci_prepare,
258 		.unprepare = en7523_pci_unprepare,
259 	};
260 	struct clk_init_data init = {
261 		.name = "pcie",
262 		.ops = &pcie_gate_ops,
263 	};
264 	struct en_clk_gate *cg;
265 
266 	cg = devm_kzalloc(dev, sizeof(*cg), GFP_KERNEL);
267 	if (!cg)
268 		return NULL;
269 
270 	cg->base = np_base;
271 	cg->hw.init = &init;
272 	en7523_pci_unprepare(&cg->hw);
273 
274 	if (clk_hw_register(dev, &cg->hw))
275 		return NULL;
276 
277 	return &cg->hw;
278 }
279 
280 static void en7523_register_clocks(struct device *dev, struct clk_hw_onecell_data *clk_data,
281 				   void __iomem *base, void __iomem *np_base)
282 {
283 	struct clk_hw *hw;
284 	u32 rate;
285 	int i;
286 
287 	for (i = 0; i < ARRAY_SIZE(en7523_base_clks); i++) {
288 		const struct en_clk_desc *desc = &en7523_base_clks[i];
289 
290 		rate = en7523_get_base_rate(base, i);
291 		rate /= en7523_get_div(base, i);
292 
293 		hw = clk_hw_register_fixed_rate(dev, desc->name, NULL, 0, rate);
294 		if (IS_ERR(hw)) {
295 			pr_err("Failed to register clk %s: %ld\n",
296 			       desc->name, PTR_ERR(hw));
297 			continue;
298 		}
299 
300 		clk_data->hws[desc->id] = hw;
301 	}
302 
303 	hw = en7523_register_pcie_clk(dev, np_base);
304 	clk_data->hws[EN7523_CLK_PCIE] = hw;
305 
306 	clk_data->num = EN7523_NUM_CLOCKS;
307 }
308 
309 static int en7523_clk_probe(struct platform_device *pdev)
310 {
311 	struct device_node *node = pdev->dev.of_node;
312 	struct clk_hw_onecell_data *clk_data;
313 	void __iomem *base, *np_base;
314 	int r;
315 
316 	base = devm_platform_ioremap_resource(pdev, 0);
317 	if (IS_ERR(base))
318 		return PTR_ERR(base);
319 
320 	np_base = devm_platform_ioremap_resource(pdev, 1);
321 	if (IS_ERR(np_base))
322 		return PTR_ERR(np_base);
323 
324 	clk_data = devm_kzalloc(&pdev->dev,
325 				struct_size(clk_data, hws, EN7523_NUM_CLOCKS),
326 				GFP_KERNEL);
327 	if (!clk_data)
328 		return -ENOMEM;
329 
330 	en7523_register_clocks(&pdev->dev, clk_data, base, np_base);
331 
332 	r = of_clk_add_hw_provider(node, of_clk_hw_onecell_get, clk_data);
333 	if (r)
334 		dev_err(&pdev->dev,
335 			"could not register clock provider: %s: %d\n",
336 			pdev->name, r);
337 
338 	return r;
339 }
340 
341 static struct platform_driver clk_en7523_drv = {
342 	.probe = en7523_clk_probe,
343 	.driver = {
344 		.name = "clk-en7523",
345 		.of_match_table = of_match_clk_en7523,
346 		.suppress_bind_attrs = true,
347 	},
348 };
349 
350 static int __init clk_en7523_init(void)
351 {
352 	return platform_driver_register(&clk_en7523_drv);
353 }
354 
355 arch_initcall(clk_en7523_init);
356