xref: /openbmc/linux/drivers/clk/keystone/pll.c (revision 6db6b729)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * PLL clock driver for Keystone devices
4  *
5  * Copyright (C) 2013 Texas Instruments Inc.
6  *	Murali Karicheri <m-karicheri2@ti.com>
7  *	Santosh Shilimkar <santosh.shilimkar@ti.com>
8  */
9 #include <linux/clk-provider.h>
10 #include <linux/err.h>
11 #include <linux/io.h>
12 #include <linux/slab.h>
13 #include <linux/of_address.h>
14 #include <linux/of.h>
15 #include <linux/module.h>
16 
17 #define PLLM_LOW_MASK		0x3f
18 #define PLLM_HIGH_MASK		0x7ffc0
19 #define MAIN_PLLM_HIGH_MASK	0x7f000
20 #define PLLM_HIGH_SHIFT		6
21 #define PLLD_MASK		0x3f
22 #define CLKOD_MASK		0x780000
23 #define CLKOD_SHIFT		19
24 
25 /**
26  * struct clk_pll_data - pll data structure
27  * @has_pllctrl: If set to non zero, lower 6 bits of multiplier is in pllm
28  *	register of pll controller, else it is in the pll_ctrl0((bit 11-6)
29  * @phy_pllm: Physical address of PLLM in pll controller. Used when
30  *	has_pllctrl is non zero.
31  * @phy_pll_ctl0: Physical address of PLL ctrl0. This could be that of
32  *	Main PLL or any other PLLs in the device such as ARM PLL, DDR PLL
33  *	or PA PLL available on keystone2. These PLLs are controlled by
34  *	this register. Main PLL is controlled by a PLL controller.
35  * @pllm: PLL register map address for multiplier bits
36  * @pllod: PLL register map address for post divider bits
37  * @pll_ctl0: PLL controller map address
38  * @pllm_lower_mask: multiplier lower mask
39  * @pllm_upper_mask: multiplier upper mask
40  * @pllm_upper_shift: multiplier upper shift
41  * @plld_mask: divider mask
42  * @clkod_mask: output divider mask
43  * @clkod_shift: output divider shift
44  * @plld_mask: divider mask
45  * @postdiv: Fixed post divider
46  */
47 struct clk_pll_data {
48 	bool has_pllctrl;
49 	u32 phy_pllm;
50 	u32 phy_pll_ctl0;
51 	void __iomem *pllm;
52 	void __iomem *pllod;
53 	void __iomem *pll_ctl0;
54 	u32 pllm_lower_mask;
55 	u32 pllm_upper_mask;
56 	u32 pllm_upper_shift;
57 	u32 plld_mask;
58 	u32 clkod_mask;
59 	u32 clkod_shift;
60 	u32 postdiv;
61 };
62 
63 /**
64  * struct clk_pll - Main pll clock
65  * @hw: clk_hw for the pll
66  * @pll_data: PLL driver specific data
67  */
68 struct clk_pll {
69 	struct clk_hw hw;
70 	struct clk_pll_data *pll_data;
71 };
72 
73 #define to_clk_pll(_hw) container_of(_hw, struct clk_pll, hw)
74 
75 static unsigned long clk_pllclk_recalc(struct clk_hw *hw,
76 					unsigned long parent_rate)
77 {
78 	struct clk_pll *pll = to_clk_pll(hw);
79 	struct clk_pll_data *pll_data = pll->pll_data;
80 	unsigned long rate = parent_rate;
81 	u32  mult = 0, prediv, postdiv, val;
82 
83 	/*
84 	 * get bits 0-5 of multiplier from pllctrl PLLM register
85 	 * if has_pllctrl is non zero
86 	 */
87 	if (pll_data->has_pllctrl) {
88 		val = readl(pll_data->pllm);
89 		mult = (val & pll_data->pllm_lower_mask);
90 	}
91 
92 	/* bit6-12 of PLLM is in Main PLL control register */
93 	val = readl(pll_data->pll_ctl0);
94 	mult |= ((val & pll_data->pllm_upper_mask)
95 			>> pll_data->pllm_upper_shift);
96 	prediv = (val & pll_data->plld_mask);
97 
98 	if (!pll_data->has_pllctrl)
99 		/* read post divider from od bits*/
100 		postdiv = ((val & pll_data->clkod_mask) >>
101 				 pll_data->clkod_shift) + 1;
102 	else if (pll_data->pllod) {
103 		postdiv = readl(pll_data->pllod);
104 		postdiv = ((postdiv & pll_data->clkod_mask) >>
105 				pll_data->clkod_shift) + 1;
106 	} else
107 		postdiv = pll_data->postdiv;
108 
109 	rate /= (prediv + 1);
110 	rate = (rate * (mult + 1));
111 	rate /= postdiv;
112 
113 	return rate;
114 }
115 
116 static const struct clk_ops clk_pll_ops = {
117 	.recalc_rate = clk_pllclk_recalc,
118 };
119 
120 static struct clk *clk_register_pll(struct device *dev,
121 			const char *name,
122 			const char *parent_name,
123 			struct clk_pll_data *pll_data)
124 {
125 	struct clk_init_data init;
126 	struct clk_pll *pll;
127 	struct clk *clk;
128 
129 	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
130 	if (!pll)
131 		return ERR_PTR(-ENOMEM);
132 
133 	init.name = name;
134 	init.ops = &clk_pll_ops;
135 	init.flags = 0;
136 	init.parent_names = (parent_name ? &parent_name : NULL);
137 	init.num_parents = (parent_name ? 1 : 0);
138 
139 	pll->pll_data	= pll_data;
140 	pll->hw.init = &init;
141 
142 	clk = clk_register(NULL, &pll->hw);
143 	if (IS_ERR(clk))
144 		goto out;
145 
146 	return clk;
147 out:
148 	kfree(pll);
149 	return NULL;
150 }
151 
152 /**
153  * _of_pll_clk_init - PLL initialisation via DT
154  * @node: device tree node for this clock
155  * @pllctrl: If true, lower 6 bits of multiplier is in pllm register of
156  *		pll controller, else it is in the control register0(bit 11-6)
157  */
158 static void __init _of_pll_clk_init(struct device_node *node, bool pllctrl)
159 {
160 	struct clk_pll_data *pll_data;
161 	const char *parent_name;
162 	struct clk *clk;
163 	int i;
164 
165 	pll_data = kzalloc(sizeof(*pll_data), GFP_KERNEL);
166 	if (!pll_data) {
167 		pr_err("%s: Out of memory\n", __func__);
168 		return;
169 	}
170 
171 	parent_name = of_clk_get_parent_name(node, 0);
172 	if (of_property_read_u32(node, "fixed-postdiv",	&pll_data->postdiv)) {
173 		/* assume the PLL has output divider register bits */
174 		pll_data->clkod_mask = CLKOD_MASK;
175 		pll_data->clkod_shift = CLKOD_SHIFT;
176 
177 		/*
178 		 * Check if there is an post-divider register. If not
179 		 * assume od bits are part of control register.
180 		 */
181 		i = of_property_match_string(node, "reg-names",
182 					     "post-divider");
183 		pll_data->pllod = of_iomap(node, i);
184 	}
185 
186 	i = of_property_match_string(node, "reg-names", "control");
187 	pll_data->pll_ctl0 = of_iomap(node, i);
188 	if (!pll_data->pll_ctl0) {
189 		pr_err("%s: ioremap failed\n", __func__);
190 		iounmap(pll_data->pllod);
191 		goto out;
192 	}
193 
194 	pll_data->pllm_lower_mask = PLLM_LOW_MASK;
195 	pll_data->pllm_upper_shift = PLLM_HIGH_SHIFT;
196 	pll_data->plld_mask = PLLD_MASK;
197 	pll_data->has_pllctrl = pllctrl;
198 	if (!pll_data->has_pllctrl) {
199 		pll_data->pllm_upper_mask = PLLM_HIGH_MASK;
200 	} else {
201 		pll_data->pllm_upper_mask = MAIN_PLLM_HIGH_MASK;
202 		i = of_property_match_string(node, "reg-names", "multiplier");
203 		pll_data->pllm = of_iomap(node, i);
204 		if (!pll_data->pllm) {
205 			iounmap(pll_data->pll_ctl0);
206 			iounmap(pll_data->pllod);
207 			goto out;
208 		}
209 	}
210 
211 	clk = clk_register_pll(NULL, node->name, parent_name, pll_data);
212 	if (!IS_ERR_OR_NULL(clk)) {
213 		of_clk_add_provider(node, of_clk_src_simple_get, clk);
214 		return;
215 	}
216 
217 out:
218 	pr_err("%s: error initializing pll %pOFn\n", __func__, node);
219 	kfree(pll_data);
220 }
221 
222 /**
223  * of_keystone_pll_clk_init - PLL initialisation DT wrapper
224  * @node: device tree node for this clock
225  */
226 static void __init of_keystone_pll_clk_init(struct device_node *node)
227 {
228 	_of_pll_clk_init(node, false);
229 }
230 CLK_OF_DECLARE(keystone_pll_clock, "ti,keystone,pll-clock",
231 					of_keystone_pll_clk_init);
232 
233 /**
234  * of_keystone_main_pll_clk_init - Main PLL initialisation DT wrapper
235  * @node: device tree node for this clock
236  */
237 static void __init of_keystone_main_pll_clk_init(struct device_node *node)
238 {
239 	_of_pll_clk_init(node, true);
240 }
241 CLK_OF_DECLARE(keystone_main_pll_clock, "ti,keystone,main-pll-clock",
242 						of_keystone_main_pll_clk_init);
243 
244 /**
245  * of_pll_div_clk_init - PLL divider setup function
246  * @node: device tree node for this clock
247  */
248 static void __init of_pll_div_clk_init(struct device_node *node)
249 {
250 	const char *parent_name;
251 	void __iomem *reg;
252 	u32 shift, mask;
253 	struct clk *clk;
254 	const char *clk_name = node->name;
255 
256 	of_property_read_string(node, "clock-output-names", &clk_name);
257 	reg = of_iomap(node, 0);
258 	if (!reg) {
259 		pr_err("%s: ioremap failed\n", __func__);
260 		return;
261 	}
262 
263 	parent_name = of_clk_get_parent_name(node, 0);
264 	if (!parent_name) {
265 		pr_err("%s: missing parent clock\n", __func__);
266 		iounmap(reg);
267 		return;
268 	}
269 
270 	if (of_property_read_u32(node, "bit-shift", &shift)) {
271 		pr_err("%s: missing 'shift' property\n", __func__);
272 		iounmap(reg);
273 		return;
274 	}
275 
276 	if (of_property_read_u32(node, "bit-mask", &mask)) {
277 		pr_err("%s: missing 'bit-mask' property\n", __func__);
278 		iounmap(reg);
279 		return;
280 	}
281 
282 	clk = clk_register_divider(NULL, clk_name, parent_name, 0, reg, shift,
283 				 mask, 0, NULL);
284 	if (clk) {
285 		of_clk_add_provider(node, of_clk_src_simple_get, clk);
286 	} else {
287 		pr_err("%s: error registering divider %s\n", __func__, clk_name);
288 		iounmap(reg);
289 	}
290 }
291 CLK_OF_DECLARE(pll_divider_clock, "ti,keystone,pll-divider-clock", of_pll_div_clk_init);
292 
293 /**
294  * of_pll_mux_clk_init - PLL mux setup function
295  * @node: device tree node for this clock
296  */
297 static void __init of_pll_mux_clk_init(struct device_node *node)
298 {
299 	void __iomem *reg;
300 	u32 shift, mask;
301 	struct clk *clk;
302 	const char *parents[2];
303 	const char *clk_name = node->name;
304 
305 	of_property_read_string(node, "clock-output-names", &clk_name);
306 	reg = of_iomap(node, 0);
307 	if (!reg) {
308 		pr_err("%s: ioremap failed\n", __func__);
309 		return;
310 	}
311 
312 	of_clk_parent_fill(node, parents, 2);
313 	if (!parents[0] || !parents[1]) {
314 		pr_err("%s: missing parent clocks\n", __func__);
315 		return;
316 	}
317 
318 	if (of_property_read_u32(node, "bit-shift", &shift)) {
319 		pr_err("%s: missing 'shift' property\n", __func__);
320 		return;
321 	}
322 
323 	if (of_property_read_u32(node, "bit-mask", &mask)) {
324 		pr_err("%s: missing 'bit-mask' property\n", __func__);
325 		return;
326 	}
327 
328 	clk = clk_register_mux(NULL, clk_name, (const char **)&parents,
329 				ARRAY_SIZE(parents) , 0, reg, shift, mask,
330 				0, NULL);
331 	if (clk)
332 		of_clk_add_provider(node, of_clk_src_simple_get, clk);
333 	else
334 		pr_err("%s: error registering mux %s\n", __func__, clk_name);
335 }
336 CLK_OF_DECLARE(pll_mux_clock, "ti,keystone,pll-mux-clock", of_pll_mux_clk_init);
337 
338 MODULE_LICENSE("GPL");
339 MODULE_DESCRIPTION("PLL clock driver for Keystone devices");
340 MODULE_AUTHOR("Murali Karicheri <m-karicheri2@ti.com>");
341 MODULE_AUTHOR("Santosh Shilimkar <santosh.shilimkar@ti.com>");
342