xref: /openbmc/linux/drivers/clk/clk-en7523.c (revision a9ebfc40)
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 };
44 
45 struct en_clk_gate {
46 	void __iomem *base;
47 	struct clk_hw hw;
48 };
49 
50 static const u32 gsw_base[] = { 400000000, 500000000 };
51 static const u32 emi_base[] = { 333000000, 400000000 };
52 static const u32 bus_base[] = { 500000000, 540000000 };
53 static const u32 slic_base[] = { 100000000, 3125000 };
54 static const u32 npu_base[] = { 333000000, 400000000, 500000000 };
55 
56 static const struct en_clk_desc en7523_base_clks[] = {
57 	{
58 		.id = EN7523_CLK_GSW,
59 		.name = "gsw",
60 
61 		.base_reg = REG_GSW_CLK_DIV_SEL,
62 		.base_bits = 1,
63 		.base_shift = 8,
64 		.base_values = gsw_base,
65 		.n_base_values = ARRAY_SIZE(gsw_base),
66 
67 		.div_bits = 3,
68 		.div_shift = 0,
69 		.div_step = 1,
70 	}, {
71 		.id = EN7523_CLK_EMI,
72 		.name = "emi",
73 
74 		.base_reg = REG_EMI_CLK_DIV_SEL,
75 		.base_bits = 1,
76 		.base_shift = 8,
77 		.base_values = emi_base,
78 		.n_base_values = ARRAY_SIZE(emi_base),
79 
80 		.div_bits = 3,
81 		.div_shift = 0,
82 		.div_step = 1,
83 	}, {
84 		.id = EN7523_CLK_BUS,
85 		.name = "bus",
86 
87 		.base_reg = REG_BUS_CLK_DIV_SEL,
88 		.base_bits = 1,
89 		.base_shift = 8,
90 		.base_values = bus_base,
91 		.n_base_values = ARRAY_SIZE(bus_base),
92 
93 		.div_bits = 3,
94 		.div_shift = 0,
95 		.div_step = 1,
96 	}, {
97 		.id = EN7523_CLK_SLIC,
98 		.name = "slic",
99 
100 		.base_reg = REG_SPI_CLK_FREQ_SEL,
101 		.base_bits = 1,
102 		.base_shift = 0,
103 		.base_values = slic_base,
104 		.n_base_values = ARRAY_SIZE(slic_base),
105 
106 		.div_reg = REG_SPI_CLK_DIV_SEL,
107 		.div_bits = 5,
108 		.div_shift = 24,
109 		.div_val0 = 20,
110 		.div_step = 2,
111 	}, {
112 		.id = EN7523_CLK_SPI,
113 		.name = "spi",
114 
115 		.base_reg = REG_SPI_CLK_DIV_SEL,
116 
117 		.base_value = 400000000,
118 
119 		.div_bits = 5,
120 		.div_shift = 8,
121 		.div_val0 = 40,
122 		.div_step = 2,
123 	}, {
124 		.id = EN7523_CLK_NPU,
125 		.name = "npu",
126 
127 		.base_reg = REG_NPU_CLK_DIV_SEL,
128 		.base_bits = 2,
129 		.base_shift = 8,
130 		.base_values = npu_base,
131 		.n_base_values = ARRAY_SIZE(npu_base),
132 
133 		.div_bits = 3,
134 		.div_shift = 0,
135 		.div_step = 1,
136 	}, {
137 		.id = EN7523_CLK_CRYPTO,
138 		.name = "crypto",
139 
140 		.base_reg = REG_CRYPTO_CLKSRC,
141 		.base_bits = 1,
142 		.base_shift = 8,
143 		.base_values = emi_base,
144 		.n_base_values = ARRAY_SIZE(emi_base),
145 	}
146 };
147 
148 static const struct of_device_id of_match_clk_en7523[] = {
149 	{ .compatible = "airoha,en7523-scu", },
150 	{ /* sentinel */ }
151 };
152 
153 static unsigned int en7523_get_base_rate(void __iomem *base, unsigned int i)
154 {
155 	const struct en_clk_desc *desc = &en7523_base_clks[i];
156 	u32 val;
157 
158 	if (!desc->base_bits)
159 		return desc->base_value;
160 
161 	val = readl(base + desc->base_reg);
162 	val >>= desc->base_shift;
163 	val &= (1 << desc->base_bits) - 1;
164 
165 	if (val >= desc->n_base_values)
166 		return 0;
167 
168 	return desc->base_values[val];
169 }
170 
171 static u32 en7523_get_div(void __iomem *base, int i)
172 {
173 	const struct en_clk_desc *desc = &en7523_base_clks[i];
174 	u32 reg, val;
175 
176 	if (!desc->div_bits)
177 		return 1;
178 
179 	reg = desc->div_reg ? desc->div_reg : desc->base_reg;
180 	val = readl(base + reg);
181 	val >>= desc->div_shift;
182 	val &= (1 << desc->div_bits) - 1;
183 
184 	if (!val && desc->div_val0)
185 		return desc->div_val0;
186 
187 	return (val + 1) * desc->div_step;
188 }
189 
190 static int en7523_pci_is_enabled(struct clk_hw *hw)
191 {
192 	struct en_clk_gate *cg = container_of(hw, struct en_clk_gate, hw);
193 
194 	return !!(readl(cg->base + REG_PCI_CONTROL) & REG_PCI_CONTROL_REFCLK_EN1);
195 }
196 
197 static int en7523_pci_prepare(struct clk_hw *hw)
198 {
199 	struct en_clk_gate *cg = container_of(hw, struct en_clk_gate, hw);
200 	void __iomem *np_base = cg->base;
201 	u32 val, mask;
202 
203 	/* Need to pull device low before reset */
204 	val = readl(np_base + REG_PCI_CONTROL);
205 	val &= ~(REG_PCI_CONTROL_PERSTOUT1 | REG_PCI_CONTROL_PERSTOUT);
206 	writel(val, np_base + REG_PCI_CONTROL);
207 	usleep_range(1000, 2000);
208 
209 	/* Enable PCIe port 1 */
210 	val |= REG_PCI_CONTROL_REFCLK_EN1;
211 	writel(val, np_base + REG_PCI_CONTROL);
212 	usleep_range(1000, 2000);
213 
214 	/* Reset to default */
215 	val = readl(np_base + REG_RESET_CONTROL);
216 	mask = REG_RESET_CONTROL_PCIE1 | REG_RESET_CONTROL_PCIE2 |
217 	       REG_RESET_CONTROL_PCIEHB;
218 	writel(val & ~mask, np_base + REG_RESET_CONTROL);
219 	usleep_range(1000, 2000);
220 	writel(val | mask, np_base + REG_RESET_CONTROL);
221 	msleep(100);
222 	writel(val & ~mask, np_base + REG_RESET_CONTROL);
223 	usleep_range(5000, 10000);
224 
225 	/* Release device */
226 	mask = REG_PCI_CONTROL_PERSTOUT1 | REG_PCI_CONTROL_PERSTOUT;
227 	val = readl(np_base + REG_PCI_CONTROL);
228 	writel(val & ~mask, np_base + REG_PCI_CONTROL);
229 	usleep_range(1000, 2000);
230 	writel(val | mask, np_base + REG_PCI_CONTROL);
231 	msleep(250);
232 
233 	return 0;
234 }
235 
236 static void en7523_pci_unprepare(struct clk_hw *hw)
237 {
238 	struct en_clk_gate *cg = container_of(hw, struct en_clk_gate, hw);
239 	void __iomem *np_base = cg->base;
240 	u32 val;
241 
242 	val = readl(np_base + REG_PCI_CONTROL);
243 	val &= ~REG_PCI_CONTROL_REFCLK_EN1;
244 	writel(val, np_base + REG_PCI_CONTROL);
245 }
246 
247 static struct clk_hw *en7523_register_pcie_clk(struct device *dev,
248 					       void __iomem *np_base)
249 {
250 	static const struct clk_ops pcie_gate_ops = {
251 		.is_enabled = en7523_pci_is_enabled,
252 		.prepare = en7523_pci_prepare,
253 		.unprepare = en7523_pci_unprepare,
254 	};
255 	struct clk_init_data init = {
256 		.name = "pcie",
257 		.ops = &pcie_gate_ops,
258 	};
259 	struct en_clk_gate *cg;
260 
261 	cg = devm_kzalloc(dev, sizeof(*cg), GFP_KERNEL);
262 	if (!cg)
263 		return NULL;
264 
265 	cg->base = np_base;
266 	cg->hw.init = &init;
267 	en7523_pci_unprepare(&cg->hw);
268 
269 	if (clk_hw_register(dev, &cg->hw))
270 		return NULL;
271 
272 	return &cg->hw;
273 }
274 
275 static void en7523_register_clocks(struct device *dev, struct clk_hw_onecell_data *clk_data,
276 				   void __iomem *base, void __iomem *np_base)
277 {
278 	struct clk_hw *hw;
279 	u32 rate;
280 	int i;
281 
282 	for (i = 0; i < ARRAY_SIZE(en7523_base_clks); i++) {
283 		const struct en_clk_desc *desc = &en7523_base_clks[i];
284 
285 		rate = en7523_get_base_rate(base, i);
286 		rate /= en7523_get_div(base, i);
287 
288 		hw = clk_hw_register_fixed_rate(dev, desc->name, NULL, 0, rate);
289 		if (IS_ERR(hw)) {
290 			pr_err("Failed to register clk %s: %ld\n",
291 			       desc->name, PTR_ERR(hw));
292 			continue;
293 		}
294 
295 		clk_data->hws[desc->id] = hw;
296 	}
297 
298 	hw = en7523_register_pcie_clk(dev, np_base);
299 	clk_data->hws[EN7523_CLK_PCIE] = hw;
300 
301 	clk_data->num = EN7523_NUM_CLOCKS;
302 }
303 
304 static int en7523_clk_probe(struct platform_device *pdev)
305 {
306 	struct device_node *node = pdev->dev.of_node;
307 	struct clk_hw_onecell_data *clk_data;
308 	void __iomem *base, *np_base;
309 	int r;
310 
311 	base = devm_platform_ioremap_resource(pdev, 0);
312 	if (IS_ERR(base))
313 		return PTR_ERR(base);
314 
315 	np_base = devm_platform_ioremap_resource(pdev, 1);
316 	if (IS_ERR(np_base))
317 		return PTR_ERR(np_base);
318 
319 	clk_data = devm_kzalloc(&pdev->dev,
320 				struct_size(clk_data, hws, EN7523_NUM_CLOCKS),
321 				GFP_KERNEL);
322 	if (!clk_data)
323 		return -ENOMEM;
324 
325 	en7523_register_clocks(&pdev->dev, clk_data, base, np_base);
326 
327 	r = of_clk_add_hw_provider(node, of_clk_hw_onecell_get, clk_data);
328 	if (r)
329 		dev_err(&pdev->dev,
330 			"could not register clock provider: %s: %d\n",
331 			pdev->name, r);
332 
333 	return r;
334 }
335 
336 static struct platform_driver clk_en7523_drv = {
337 	.probe = en7523_clk_probe,
338 	.driver = {
339 		.name = "clk-en7523",
340 		.of_match_table = of_match_clk_en7523,
341 		.suppress_bind_attrs = true,
342 	},
343 };
344 
345 static int __init clk_en7523_init(void)
346 {
347 	return platform_driver_register(&clk_en7523_drv);
348 }
349 
350 arch_initcall(clk_en7523_init);
351