xref: /openbmc/linux/drivers/clk/clk-en7523.c (revision e65e175b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 
3 #include <linux/delay.h>
4 #include <linux/clk-provider.h>
5 #include <linux/of.h>
6 #include <linux/of_address.h>
7 #include <linux/of_device.h>
8 #include <linux/platform_device.h>
9 #include <dt-bindings/clock/en7523-clk.h>
10 
11 #define REG_PCI_CONTROL			0x88
12 #define   REG_PCI_CONTROL_PERSTOUT	BIT(29)
13 #define   REG_PCI_CONTROL_PERSTOUT1	BIT(26)
14 #define   REG_PCI_CONTROL_REFCLK_EN1	BIT(22)
15 #define REG_GSW_CLK_DIV_SEL		0x1b4
16 #define REG_EMI_CLK_DIV_SEL		0x1b8
17 #define REG_BUS_CLK_DIV_SEL		0x1bc
18 #define REG_SPI_CLK_DIV_SEL		0x1c4
19 #define REG_SPI_CLK_FREQ_SEL		0x1c8
20 #define REG_NPU_CLK_DIV_SEL		0x1fc
21 #define REG_CRYPTO_CLKSRC		0x200
22 #define REG_RESET_CONTROL		0x834
23 #define   REG_RESET_CONTROL_PCIEHB	BIT(29)
24 #define   REG_RESET_CONTROL_PCIE1	BIT(27)
25 #define   REG_RESET_CONTROL_PCIE2	BIT(26)
26 
27 struct en_clk_desc {
28 	int id;
29 	const char *name;
30 	u32 base_reg;
31 	u8 base_bits;
32 	u8 base_shift;
33 	union {
34 		const unsigned int *base_values;
35 		unsigned int base_value;
36 	};
37 	size_t n_base_values;
38 
39 	u16 div_reg;
40 	u8 div_bits;
41 	u8 div_shift;
42 	u16 div_val0;
43 	u8 div_step;
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 	}, {
72 		.id = EN7523_CLK_EMI,
73 		.name = "emi",
74 
75 		.base_reg = REG_EMI_CLK_DIV_SEL,
76 		.base_bits = 1,
77 		.base_shift = 8,
78 		.base_values = emi_base,
79 		.n_base_values = ARRAY_SIZE(emi_base),
80 
81 		.div_bits = 3,
82 		.div_shift = 0,
83 		.div_step = 1,
84 	}, {
85 		.id = EN7523_CLK_BUS,
86 		.name = "bus",
87 
88 		.base_reg = REG_BUS_CLK_DIV_SEL,
89 		.base_bits = 1,
90 		.base_shift = 8,
91 		.base_values = bus_base,
92 		.n_base_values = ARRAY_SIZE(bus_base),
93 
94 		.div_bits = 3,
95 		.div_shift = 0,
96 		.div_step = 1,
97 	}, {
98 		.id = EN7523_CLK_SLIC,
99 		.name = "slic",
100 
101 		.base_reg = REG_SPI_CLK_FREQ_SEL,
102 		.base_bits = 1,
103 		.base_shift = 0,
104 		.base_values = slic_base,
105 		.n_base_values = ARRAY_SIZE(slic_base),
106 
107 		.div_reg = REG_SPI_CLK_DIV_SEL,
108 		.div_bits = 5,
109 		.div_shift = 24,
110 		.div_val0 = 20,
111 		.div_step = 2,
112 	}, {
113 		.id = EN7523_CLK_SPI,
114 		.name = "spi",
115 
116 		.base_reg = REG_SPI_CLK_DIV_SEL,
117 
118 		.base_value = 400000000,
119 
120 		.div_bits = 5,
121 		.div_shift = 8,
122 		.div_val0 = 40,
123 		.div_step = 2,
124 	}, {
125 		.id = EN7523_CLK_NPU,
126 		.name = "npu",
127 
128 		.base_reg = REG_NPU_CLK_DIV_SEL,
129 		.base_bits = 2,
130 		.base_shift = 8,
131 		.base_values = npu_base,
132 		.n_base_values = ARRAY_SIZE(npu_base),
133 
134 		.div_bits = 3,
135 		.div_shift = 0,
136 		.div_step = 1,
137 	}, {
138 		.id = EN7523_CLK_CRYPTO,
139 		.name = "crypto",
140 
141 		.base_reg = REG_CRYPTO_CLKSRC,
142 		.base_bits = 1,
143 		.base_shift = 8,
144 		.base_values = emi_base,
145 		.n_base_values = ARRAY_SIZE(emi_base),
146 	}
147 };
148 
149 static const struct of_device_id of_match_clk_en7523[] = {
150 	{ .compatible = "airoha,en7523-scu", },
151 	{ /* sentinel */ }
152 };
153 
154 static unsigned int en7523_get_base_rate(void __iomem *base, unsigned int i)
155 {
156 	const struct en_clk_desc *desc = &en7523_base_clks[i];
157 	u32 val;
158 
159 	if (!desc->base_bits)
160 		return desc->base_value;
161 
162 	val = readl(base + desc->base_reg);
163 	val >>= desc->base_shift;
164 	val &= (1 << desc->base_bits) - 1;
165 
166 	if (val >= desc->n_base_values)
167 		return 0;
168 
169 	return desc->base_values[val];
170 }
171 
172 static u32 en7523_get_div(void __iomem *base, int i)
173 {
174 	const struct en_clk_desc *desc = &en7523_base_clks[i];
175 	u32 reg, val;
176 
177 	if (!desc->div_bits)
178 		return 1;
179 
180 	reg = desc->div_reg ? desc->div_reg : desc->base_reg;
181 	val = readl(base + reg);
182 	val >>= desc->div_shift;
183 	val &= (1 << desc->div_bits) - 1;
184 
185 	if (!val && desc->div_val0)
186 		return desc->div_val0;
187 
188 	return (val + 1) * desc->div_step;
189 }
190 
191 static int en7523_pci_is_enabled(struct clk_hw *hw)
192 {
193 	struct en_clk_gate *cg = container_of(hw, struct en_clk_gate, hw);
194 
195 	return !!(readl(cg->base + REG_PCI_CONTROL) & REG_PCI_CONTROL_REFCLK_EN1);
196 }
197 
198 static int en7523_pci_prepare(struct clk_hw *hw)
199 {
200 	struct en_clk_gate *cg = container_of(hw, struct en_clk_gate, hw);
201 	void __iomem *np_base = cg->base;
202 	u32 val, mask;
203 
204 	/* Need to pull device low before reset */
205 	val = readl(np_base + REG_PCI_CONTROL);
206 	val &= ~(REG_PCI_CONTROL_PERSTOUT1 | REG_PCI_CONTROL_PERSTOUT);
207 	writel(val, np_base + REG_PCI_CONTROL);
208 	usleep_range(1000, 2000);
209 
210 	/* Enable PCIe port 1 */
211 	val |= REG_PCI_CONTROL_REFCLK_EN1;
212 	writel(val, np_base + REG_PCI_CONTROL);
213 	usleep_range(1000, 2000);
214 
215 	/* Reset to default */
216 	val = readl(np_base + REG_RESET_CONTROL);
217 	mask = REG_RESET_CONTROL_PCIE1 | REG_RESET_CONTROL_PCIE2 |
218 	       REG_RESET_CONTROL_PCIEHB;
219 	writel(val & ~mask, np_base + REG_RESET_CONTROL);
220 	usleep_range(1000, 2000);
221 	writel(val | mask, np_base + REG_RESET_CONTROL);
222 	msleep(100);
223 	writel(val & ~mask, np_base + REG_RESET_CONTROL);
224 	usleep_range(5000, 10000);
225 
226 	/* Release device */
227 	mask = REG_PCI_CONTROL_PERSTOUT1 | REG_PCI_CONTROL_PERSTOUT;
228 	val = readl(np_base + REG_PCI_CONTROL);
229 	writel(val & ~mask, np_base + REG_PCI_CONTROL);
230 	usleep_range(1000, 2000);
231 	writel(val | mask, np_base + REG_PCI_CONTROL);
232 	msleep(250);
233 
234 	return 0;
235 }
236 
237 static void en7523_pci_unprepare(struct clk_hw *hw)
238 {
239 	struct en_clk_gate *cg = container_of(hw, struct en_clk_gate, hw);
240 	void __iomem *np_base = cg->base;
241 	u32 val;
242 
243 	val = readl(np_base + REG_PCI_CONTROL);
244 	val &= ~REG_PCI_CONTROL_REFCLK_EN1;
245 	writel(val, np_base + REG_PCI_CONTROL);
246 }
247 
248 static struct clk_hw *en7523_register_pcie_clk(struct device *dev,
249 					       void __iomem *np_base)
250 {
251 	static const struct clk_ops pcie_gate_ops = {
252 		.is_enabled = en7523_pci_is_enabled,
253 		.prepare = en7523_pci_prepare,
254 		.unprepare = en7523_pci_unprepare,
255 	};
256 	struct clk_init_data init = {
257 		.name = "pcie",
258 		.ops = &pcie_gate_ops,
259 	};
260 	struct en_clk_gate *cg;
261 
262 	cg = devm_kzalloc(dev, sizeof(*cg), GFP_KERNEL);
263 	if (!cg)
264 		return NULL;
265 
266 	cg->base = np_base;
267 	cg->hw.init = &init;
268 	en7523_pci_unprepare(&cg->hw);
269 
270 	if (clk_hw_register(dev, &cg->hw))
271 		return NULL;
272 
273 	return &cg->hw;
274 }
275 
276 static void en7523_register_clocks(struct device *dev, struct clk_hw_onecell_data *clk_data,
277 				   void __iomem *base, void __iomem *np_base)
278 {
279 	struct clk_hw *hw;
280 	u32 rate;
281 	int i;
282 
283 	for (i = 0; i < ARRAY_SIZE(en7523_base_clks); i++) {
284 		const struct en_clk_desc *desc = &en7523_base_clks[i];
285 
286 		rate = en7523_get_base_rate(base, i);
287 		rate /= en7523_get_div(base, i);
288 
289 		hw = clk_hw_register_fixed_rate(dev, desc->name, NULL, 0, rate);
290 		if (IS_ERR(hw)) {
291 			pr_err("Failed to register clk %s: %ld\n",
292 			       desc->name, PTR_ERR(hw));
293 			continue;
294 		}
295 
296 		clk_data->hws[desc->id] = hw;
297 	}
298 
299 	hw = en7523_register_pcie_clk(dev, np_base);
300 	clk_data->hws[EN7523_CLK_PCIE] = hw;
301 
302 	clk_data->num = EN7523_NUM_CLOCKS;
303 }
304 
305 static int en7523_clk_probe(struct platform_device *pdev)
306 {
307 	struct device_node *node = pdev->dev.of_node;
308 	struct clk_hw_onecell_data *clk_data;
309 	void __iomem *base, *np_base;
310 	int r;
311 
312 	base = devm_platform_ioremap_resource(pdev, 0);
313 	if (IS_ERR(base))
314 		return PTR_ERR(base);
315 
316 	np_base = devm_platform_ioremap_resource(pdev, 1);
317 	if (IS_ERR(np_base))
318 		return PTR_ERR(np_base);
319 
320 	clk_data = devm_kzalloc(&pdev->dev,
321 				struct_size(clk_data, hws, EN7523_NUM_CLOCKS),
322 				GFP_KERNEL);
323 	if (!clk_data)
324 		return -ENOMEM;
325 
326 	en7523_register_clocks(&pdev->dev, clk_data, base, np_base);
327 
328 	r = of_clk_add_hw_provider(node, of_clk_hw_onecell_get, clk_data);
329 	if (r)
330 		dev_err(&pdev->dev,
331 			"could not register clock provider: %s: %d\n",
332 			pdev->name, r);
333 
334 	return r;
335 }
336 
337 static struct platform_driver clk_en7523_drv = {
338 	.probe = en7523_clk_probe,
339 	.driver = {
340 		.name = "clk-en7523",
341 		.of_match_table = of_match_clk_en7523,
342 		.suppress_bind_attrs = true,
343 	},
344 };
345 
346 static int __init clk_en7523_init(void)
347 {
348 	return platform_driver_register(&clk_en7523_drv);
349 }
350 
351 arch_initcall(clk_en7523_init);
352