xref: /linux/drivers/clk/keystone/pll.c (revision b85d45947951d23cb22d90caecf4c1eb81342c96)
1 /*
2  * PLL clock driver for Keystone devices
3  *
4  * Copyright (C) 2013 Texas Instruments Inc.
5  *	Murali Karicheri <m-karicheri2@ti.com>
6  *	Santosh Shilimkar <santosh.shilimkar@ti.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  */
13 #include <linux/clk-provider.h>
14 #include <linux/err.h>
15 #include <linux/io.h>
16 #include <linux/slab.h>
17 #include <linux/of_address.h>
18 #include <linux/of.h>
19 #include <linux/module.h>
20 
21 #define PLLM_LOW_MASK		0x3f
22 #define PLLM_HIGH_MASK		0x7ffc0
23 #define MAIN_PLLM_HIGH_MASK	0x7f000
24 #define PLLM_HIGH_SHIFT		6
25 #define PLLD_MASK		0x3f
26 #define CLKOD_MASK		0x780000
27 #define CLKOD_SHIFT		19
28 
29 /**
30  * struct clk_pll_data - pll data structure
31  * @has_pllctrl: If set to non zero, lower 6 bits of multiplier is in pllm
32  *	register of pll controller, else it is in the pll_ctrl0((bit 11-6)
33  * @phy_pllm: Physical address of PLLM in pll controller. Used when
34  *	has_pllctrl is non zero.
35  * @phy_pll_ctl0: Physical address of PLL ctrl0. This could be that of
36  *	Main PLL or any other PLLs in the device such as ARM PLL, DDR PLL
37  *	or PA PLL available on keystone2. These PLLs are controlled by
38  *	this register. Main PLL is controlled by a PLL controller.
39  * @pllm: PLL register map address for multiplier bits
40  * @pllod: PLL register map address for post divider bits
41  * @pll_ctl0: PLL controller map address
42  * @pllm_lower_mask: multiplier lower mask
43  * @pllm_upper_mask: multiplier upper mask
44  * @pllm_upper_shift: multiplier upper shift
45  * @plld_mask: divider mask
46  * @clkod_mask: output divider mask
47  * @clkod_shift: output divider shift
48  * @plld_mask: divider mask
49  * @postdiv: Fixed post divider
50  */
51 struct clk_pll_data {
52 	bool has_pllctrl;
53 	u32 phy_pllm;
54 	u32 phy_pll_ctl0;
55 	void __iomem *pllm;
56 	void __iomem *pllod;
57 	void __iomem *pll_ctl0;
58 	u32 pllm_lower_mask;
59 	u32 pllm_upper_mask;
60 	u32 pllm_upper_shift;
61 	u32 plld_mask;
62 	u32 clkod_mask;
63 	u32 clkod_shift;
64 	u32 postdiv;
65 };
66 
67 /**
68  * struct clk_pll - Main pll clock
69  * @hw: clk_hw for the pll
70  * @pll_data: PLL driver specific data
71  */
72 struct clk_pll {
73 	struct clk_hw hw;
74 	struct clk_pll_data *pll_data;
75 };
76 
77 #define to_clk_pll(_hw) container_of(_hw, struct clk_pll, hw)
78 
79 static unsigned long clk_pllclk_recalc(struct clk_hw *hw,
80 					unsigned long parent_rate)
81 {
82 	struct clk_pll *pll = to_clk_pll(hw);
83 	struct clk_pll_data *pll_data = pll->pll_data;
84 	unsigned long rate = parent_rate;
85 	u32  mult = 0, prediv, postdiv, val;
86 
87 	/*
88 	 * get bits 0-5 of multiplier from pllctrl PLLM register
89 	 * if has_pllctrl is non zero
90 	 */
91 	if (pll_data->has_pllctrl) {
92 		val = readl(pll_data->pllm);
93 		mult = (val & pll_data->pllm_lower_mask);
94 	}
95 
96 	/* bit6-12 of PLLM is in Main PLL control register */
97 	val = readl(pll_data->pll_ctl0);
98 	mult |= ((val & pll_data->pllm_upper_mask)
99 			>> pll_data->pllm_upper_shift);
100 	prediv = (val & pll_data->plld_mask);
101 
102 	if (!pll_data->has_pllctrl)
103 		/* read post divider from od bits*/
104 		postdiv = ((val & pll_data->clkod_mask) >>
105 				 pll_data->clkod_shift) + 1;
106 	else if (pll_data->pllod) {
107 		postdiv = readl(pll_data->pllod);
108 		postdiv = ((postdiv & pll_data->clkod_mask) >>
109 				pll_data->clkod_shift) + 1;
110 	} else
111 		postdiv = pll_data->postdiv;
112 
113 	rate /= (prediv + 1);
114 	rate = (rate * (mult + 1));
115 	rate /= postdiv;
116 
117 	return rate;
118 }
119 
120 static const struct clk_ops clk_pll_ops = {
121 	.recalc_rate = clk_pllclk_recalc,
122 };
123 
124 static struct clk *clk_register_pll(struct device *dev,
125 			const char *name,
126 			const char *parent_name,
127 			struct clk_pll_data *pll_data)
128 {
129 	struct clk_init_data init;
130 	struct clk_pll *pll;
131 	struct clk *clk;
132 
133 	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
134 	if (!pll)
135 		return ERR_PTR(-ENOMEM);
136 
137 	init.name = name;
138 	init.ops = &clk_pll_ops;
139 	init.flags = 0;
140 	init.parent_names = (parent_name ? &parent_name : NULL);
141 	init.num_parents = (parent_name ? 1 : 0);
142 
143 	pll->pll_data	= pll_data;
144 	pll->hw.init = &init;
145 
146 	clk = clk_register(NULL, &pll->hw);
147 	if (IS_ERR(clk))
148 		goto out;
149 
150 	return clk;
151 out:
152 	kfree(pll);
153 	return NULL;
154 }
155 
156 /**
157  * _of_clk_init - PLL initialisation via DT
158  * @node: device tree node for this clock
159  * @pllctrl: If true, lower 6 bits of multiplier is in pllm register of
160  *		pll controller, else it is in the control regsiter0(bit 11-6)
161  */
162 static void __init _of_pll_clk_init(struct device_node *node, bool pllctrl)
163 {
164 	struct clk_pll_data *pll_data;
165 	const char *parent_name;
166 	struct clk *clk;
167 	int i;
168 
169 	pll_data = kzalloc(sizeof(*pll_data), GFP_KERNEL);
170 	if (!pll_data) {
171 		pr_err("%s: Out of memory\n", __func__);
172 		return;
173 	}
174 
175 	parent_name = of_clk_get_parent_name(node, 0);
176 	if (of_property_read_u32(node, "fixed-postdiv",	&pll_data->postdiv)) {
177 		/* assume the PLL has output divider register bits */
178 		pll_data->clkod_mask = CLKOD_MASK;
179 		pll_data->clkod_shift = CLKOD_SHIFT;
180 
181 		/*
182 		 * Check if there is an post-divider register. If not
183 		 * assume od bits are part of control register.
184 		 */
185 		i = of_property_match_string(node, "reg-names",
186 					     "post-divider");
187 		pll_data->pllod = of_iomap(node, i);
188 	}
189 
190 	i = of_property_match_string(node, "reg-names", "control");
191 	pll_data->pll_ctl0 = of_iomap(node, i);
192 	if (!pll_data->pll_ctl0) {
193 		pr_err("%s: ioremap failed\n", __func__);
194 		iounmap(pll_data->pllod);
195 		goto out;
196 	}
197 
198 	pll_data->pllm_lower_mask = PLLM_LOW_MASK;
199 	pll_data->pllm_upper_shift = PLLM_HIGH_SHIFT;
200 	pll_data->plld_mask = PLLD_MASK;
201 	pll_data->has_pllctrl = pllctrl;
202 	if (!pll_data->has_pllctrl) {
203 		pll_data->pllm_upper_mask = PLLM_HIGH_MASK;
204 	} else {
205 		pll_data->pllm_upper_mask = MAIN_PLLM_HIGH_MASK;
206 		i = of_property_match_string(node, "reg-names", "multiplier");
207 		pll_data->pllm = of_iomap(node, i);
208 		if (!pll_data->pllm) {
209 			iounmap(pll_data->pll_ctl0);
210 			iounmap(pll_data->pllod);
211 			goto out;
212 		}
213 	}
214 
215 	clk = clk_register_pll(NULL, node->name, parent_name, pll_data);
216 	if (clk) {
217 		of_clk_add_provider(node, of_clk_src_simple_get, clk);
218 		return;
219 	}
220 
221 out:
222 	pr_err("%s: error initializing pll %s\n", __func__, node->name);
223 	kfree(pll_data);
224 }
225 
226 /**
227  * of_keystone_pll_clk_init - PLL initialisation DT wrapper
228  * @node: device tree node for this clock
229  */
230 static void __init of_keystone_pll_clk_init(struct device_node *node)
231 {
232 	_of_pll_clk_init(node, false);
233 }
234 CLK_OF_DECLARE(keystone_pll_clock, "ti,keystone,pll-clock",
235 					of_keystone_pll_clk_init);
236 
237 /**
238  * of_keystone_pll_main_clk_init - Main PLL initialisation DT wrapper
239  * @node: device tree node for this clock
240  */
241 static void __init of_keystone_main_pll_clk_init(struct device_node *node)
242 {
243 	_of_pll_clk_init(node, true);
244 }
245 CLK_OF_DECLARE(keystone_main_pll_clock, "ti,keystone,main-pll-clock",
246 						of_keystone_main_pll_clk_init);
247 
248 /**
249  * of_pll_div_clk_init - PLL divider setup function
250  * @node: device tree node for this clock
251  */
252 static void __init of_pll_div_clk_init(struct device_node *node)
253 {
254 	const char *parent_name;
255 	void __iomem *reg;
256 	u32 shift, mask;
257 	struct clk *clk;
258 	const char *clk_name = node->name;
259 
260 	of_property_read_string(node, "clock-output-names", &clk_name);
261 	reg = of_iomap(node, 0);
262 	if (!reg) {
263 		pr_err("%s: ioremap failed\n", __func__);
264 		return;
265 	}
266 
267 	parent_name = of_clk_get_parent_name(node, 0);
268 	if (!parent_name) {
269 		pr_err("%s: missing parent clock\n", __func__);
270 		return;
271 	}
272 
273 	if (of_property_read_u32(node, "bit-shift", &shift)) {
274 		pr_err("%s: missing 'shift' property\n", __func__);
275 		return;
276 	}
277 
278 	if (of_property_read_u32(node, "bit-mask", &mask)) {
279 		pr_err("%s: missing 'bit-mask' property\n", __func__);
280 		return;
281 	}
282 
283 	clk = clk_register_divider(NULL, clk_name, parent_name, 0, reg, shift,
284 				 mask, 0, NULL);
285 	if (clk)
286 		of_clk_add_provider(node, of_clk_src_simple_get, clk);
287 	else
288 		pr_err("%s: error registering divider %s\n", __func__, clk_name);
289 }
290 CLK_OF_DECLARE(pll_divider_clock, "ti,keystone,pll-divider-clock", of_pll_div_clk_init);
291 
292 /**
293  * of_pll_mux_clk_init - PLL mux setup function
294  * @node: device tree node for this clock
295  */
296 static void __init of_pll_mux_clk_init(struct device_node *node)
297 {
298 	void __iomem *reg;
299 	u32 shift, mask;
300 	struct clk *clk;
301 	const char *parents[2];
302 	const char *clk_name = node->name;
303 
304 	of_property_read_string(node, "clock-output-names", &clk_name);
305 	reg = of_iomap(node, 0);
306 	if (!reg) {
307 		pr_err("%s: ioremap failed\n", __func__);
308 		return;
309 	}
310 
311 	of_clk_parent_fill(node, parents, 2);
312 	if (!parents[0] || !parents[1]) {
313 		pr_err("%s: missing parent clocks\n", __func__);
314 		return;
315 	}
316 
317 	if (of_property_read_u32(node, "bit-shift", &shift)) {
318 		pr_err("%s: missing 'shift' property\n", __func__);
319 		return;
320 	}
321 
322 	if (of_property_read_u32(node, "bit-mask", &mask)) {
323 		pr_err("%s: missing 'bit-mask' property\n", __func__);
324 		return;
325 	}
326 
327 	clk = clk_register_mux(NULL, clk_name, (const char **)&parents,
328 				ARRAY_SIZE(parents) , 0, reg, shift, mask,
329 				0, NULL);
330 	if (clk)
331 		of_clk_add_provider(node, of_clk_src_simple_get, clk);
332 	else
333 		pr_err("%s: error registering mux %s\n", __func__, clk_name);
334 }
335 CLK_OF_DECLARE(pll_mux_clock, "ti,keystone,pll-mux-clock", of_pll_mux_clk_init);
336