xref: /openbmc/linux/drivers/clk/zynqmp/pll.c (revision d0e22329)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Zynq UltraScale+ MPSoC PLL driver
4  *
5  *  Copyright (C) 2016-2018 Xilinx
6  */
7 
8 #include <linux/clk.h>
9 #include <linux/clk-provider.h>
10 #include <linux/slab.h>
11 #include "clk-zynqmp.h"
12 
13 /**
14  * struct zynqmp_pll - PLL clock
15  * @hw:		Handle between common and hardware-specific interfaces
16  * @clk_id:	PLL clock ID
17  */
18 struct zynqmp_pll {
19 	struct clk_hw hw;
20 	u32 clk_id;
21 };
22 
23 #define to_zynqmp_pll(_hw)	container_of(_hw, struct zynqmp_pll, hw)
24 
25 #define PLL_FBDIV_MIN	25
26 #define PLL_FBDIV_MAX	125
27 
28 #define PS_PLL_VCO_MIN 1500000000
29 #define PS_PLL_VCO_MAX 3000000000UL
30 
31 enum pll_mode {
32 	PLL_MODE_INT,
33 	PLL_MODE_FRAC,
34 };
35 
36 #define FRAC_OFFSET 0x8
37 #define PLLFCFG_FRAC_EN	BIT(31)
38 #define FRAC_DIV  BIT(16)  /* 2^16 */
39 
40 /**
41  * zynqmp_pll_get_mode() - Get mode of PLL
42  * @hw:		Handle between common and hardware-specific interfaces
43  *
44  * Return: Mode of PLL
45  */
46 static inline enum pll_mode zynqmp_pll_get_mode(struct clk_hw *hw)
47 {
48 	struct zynqmp_pll *clk = to_zynqmp_pll(hw);
49 	u32 clk_id = clk->clk_id;
50 	const char *clk_name = clk_hw_get_name(hw);
51 	u32 ret_payload[PAYLOAD_ARG_CNT];
52 	int ret;
53 	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
54 
55 	ret = eemi_ops->ioctl(0, IOCTL_GET_PLL_FRAC_MODE, clk_id, 0,
56 			      ret_payload);
57 	if (ret)
58 		pr_warn_once("%s() PLL get frac mode failed for %s, ret = %d\n",
59 			     __func__, clk_name, ret);
60 
61 	return ret_payload[1];
62 }
63 
64 /**
65  * zynqmp_pll_set_mode() - Set the PLL mode
66  * @hw:		Handle between common and hardware-specific interfaces
67  * @on:		Flag to determine the mode
68  */
69 static inline void zynqmp_pll_set_mode(struct clk_hw *hw, bool on)
70 {
71 	struct zynqmp_pll *clk = to_zynqmp_pll(hw);
72 	u32 clk_id = clk->clk_id;
73 	const char *clk_name = clk_hw_get_name(hw);
74 	int ret;
75 	u32 mode;
76 	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
77 
78 	if (on)
79 		mode = PLL_MODE_FRAC;
80 	else
81 		mode = PLL_MODE_INT;
82 
83 	ret = eemi_ops->ioctl(0, IOCTL_SET_PLL_FRAC_MODE, clk_id, mode, NULL);
84 	if (ret)
85 		pr_warn_once("%s() PLL set frac mode failed for %s, ret = %d\n",
86 			     __func__, clk_name, ret);
87 }
88 
89 /**
90  * zynqmp_pll_round_rate() - Round a clock frequency
91  * @hw:		Handle between common and hardware-specific interfaces
92  * @rate:	Desired clock frequency
93  * @prate:	Clock frequency of parent clock
94  *
95  * Return: Frequency closest to @rate the hardware can generate
96  */
97 static long zynqmp_pll_round_rate(struct clk_hw *hw, unsigned long rate,
98 				  unsigned long *prate)
99 {
100 	u32 fbdiv;
101 	long rate_div, f;
102 
103 	/* Enable the fractional mode if needed */
104 	rate_div = (rate * FRAC_DIV) / *prate;
105 	f = rate_div % FRAC_DIV;
106 	zynqmp_pll_set_mode(hw, !!f);
107 
108 	if (zynqmp_pll_get_mode(hw) == PLL_MODE_FRAC) {
109 		if (rate > PS_PLL_VCO_MAX) {
110 			fbdiv = rate / PS_PLL_VCO_MAX;
111 			rate = rate / (fbdiv + 1);
112 		}
113 		if (rate < PS_PLL_VCO_MIN) {
114 			fbdiv = DIV_ROUND_UP(PS_PLL_VCO_MIN, rate);
115 			rate = rate * fbdiv;
116 		}
117 		return rate;
118 	}
119 
120 	fbdiv = DIV_ROUND_CLOSEST(rate, *prate);
121 	fbdiv = clamp_t(u32, fbdiv, PLL_FBDIV_MIN, PLL_FBDIV_MAX);
122 	return *prate * fbdiv;
123 }
124 
125 /**
126  * zynqmp_pll_recalc_rate() - Recalculate clock frequency
127  * @hw:			Handle between common and hardware-specific interfaces
128  * @parent_rate:	Clock frequency of parent clock
129  *
130  * Return: Current clock frequency
131  */
132 static unsigned long zynqmp_pll_recalc_rate(struct clk_hw *hw,
133 					    unsigned long parent_rate)
134 {
135 	struct zynqmp_pll *clk = to_zynqmp_pll(hw);
136 	u32 clk_id = clk->clk_id;
137 	const char *clk_name = clk_hw_get_name(hw);
138 	u32 fbdiv, data;
139 	unsigned long rate, frac;
140 	u32 ret_payload[PAYLOAD_ARG_CNT];
141 	int ret;
142 	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
143 
144 	ret = eemi_ops->clock_getdivider(clk_id, &fbdiv);
145 	if (ret)
146 		pr_warn_once("%s() get divider failed for %s, ret = %d\n",
147 			     __func__, clk_name, ret);
148 
149 	rate =  parent_rate * fbdiv;
150 	if (zynqmp_pll_get_mode(hw) == PLL_MODE_FRAC) {
151 		eemi_ops->ioctl(0, IOCTL_GET_PLL_FRAC_DATA, clk_id, 0,
152 				ret_payload);
153 		data = ret_payload[1];
154 		frac = (parent_rate * data) / FRAC_DIV;
155 		rate = rate + frac;
156 	}
157 
158 	return rate;
159 }
160 
161 /**
162  * zynqmp_pll_set_rate() - Set rate of PLL
163  * @hw:			Handle between common and hardware-specific interfaces
164  * @rate:		Frequency of clock to be set
165  * @parent_rate:	Clock frequency of parent clock
166  *
167  * Set PLL divider to set desired rate.
168  *
169  * Returns:            rate which is set on success else error code
170  */
171 static int zynqmp_pll_set_rate(struct clk_hw *hw, unsigned long rate,
172 			       unsigned long parent_rate)
173 {
174 	struct zynqmp_pll *clk = to_zynqmp_pll(hw);
175 	u32 clk_id = clk->clk_id;
176 	const char *clk_name = clk_hw_get_name(hw);
177 	u32 fbdiv;
178 	long rate_div, frac, m, f;
179 	int ret;
180 	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
181 
182 	if (zynqmp_pll_get_mode(hw) == PLL_MODE_FRAC) {
183 		rate_div = (rate * FRAC_DIV) / parent_rate;
184 		m = rate_div / FRAC_DIV;
185 		f = rate_div % FRAC_DIV;
186 		m = clamp_t(u32, m, (PLL_FBDIV_MIN), (PLL_FBDIV_MAX));
187 		rate = parent_rate * m;
188 		frac = (parent_rate * f) / FRAC_DIV;
189 
190 		ret = eemi_ops->clock_setdivider(clk_id, m);
191 		if (ret)
192 			pr_warn_once("%s() set divider failed for %s, ret = %d\n",
193 				     __func__, clk_name, ret);
194 
195 		eemi_ops->ioctl(0, IOCTL_SET_PLL_FRAC_DATA, clk_id, f, NULL);
196 
197 		return rate + frac;
198 	}
199 
200 	fbdiv = DIV_ROUND_CLOSEST(rate, parent_rate);
201 	fbdiv = clamp_t(u32, fbdiv, PLL_FBDIV_MIN, PLL_FBDIV_MAX);
202 	ret = eemi_ops->clock_setdivider(clk_id, fbdiv);
203 	if (ret)
204 		pr_warn_once("%s() set divider failed for %s, ret = %d\n",
205 			     __func__, clk_name, ret);
206 
207 	return parent_rate * fbdiv;
208 }
209 
210 /**
211  * zynqmp_pll_is_enabled() - Check if a clock is enabled
212  * @hw:		Handle between common and hardware-specific interfaces
213  *
214  * Return: 1 if the clock is enabled, 0 otherwise
215  */
216 static int zynqmp_pll_is_enabled(struct clk_hw *hw)
217 {
218 	struct zynqmp_pll *clk = to_zynqmp_pll(hw);
219 	const char *clk_name = clk_hw_get_name(hw);
220 	u32 clk_id = clk->clk_id;
221 	unsigned int state;
222 	int ret;
223 	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
224 
225 	ret = eemi_ops->clock_getstate(clk_id, &state);
226 	if (ret) {
227 		pr_warn_once("%s() clock get state failed for %s, ret = %d\n",
228 			     __func__, clk_name, ret);
229 		return -EIO;
230 	}
231 
232 	return state ? 1 : 0;
233 }
234 
235 /**
236  * zynqmp_pll_enable() - Enable clock
237  * @hw:		Handle between common and hardware-specific interfaces
238  *
239  * Return: 0 on success else error code
240  */
241 static int zynqmp_pll_enable(struct clk_hw *hw)
242 {
243 	struct zynqmp_pll *clk = to_zynqmp_pll(hw);
244 	const char *clk_name = clk_hw_get_name(hw);
245 	u32 clk_id = clk->clk_id;
246 	int ret;
247 	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
248 
249 	if (zynqmp_pll_is_enabled(hw))
250 		return 0;
251 
252 	ret = eemi_ops->clock_enable(clk_id);
253 	if (ret)
254 		pr_warn_once("%s() clock enable failed for %s, ret = %d\n",
255 			     __func__, clk_name, ret);
256 
257 	return ret;
258 }
259 
260 /**
261  * zynqmp_pll_disable() - Disable clock
262  * @hw:		Handle between common and hardware-specific interfaces
263  */
264 static void zynqmp_pll_disable(struct clk_hw *hw)
265 {
266 	struct zynqmp_pll *clk = to_zynqmp_pll(hw);
267 	const char *clk_name = clk_hw_get_name(hw);
268 	u32 clk_id = clk->clk_id;
269 	int ret;
270 	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
271 
272 	if (!zynqmp_pll_is_enabled(hw))
273 		return;
274 
275 	ret = eemi_ops->clock_disable(clk_id);
276 	if (ret)
277 		pr_warn_once("%s() clock disable failed for %s, ret = %d\n",
278 			     __func__, clk_name, ret);
279 }
280 
281 static const struct clk_ops zynqmp_pll_ops = {
282 	.enable = zynqmp_pll_enable,
283 	.disable = zynqmp_pll_disable,
284 	.is_enabled = zynqmp_pll_is_enabled,
285 	.round_rate = zynqmp_pll_round_rate,
286 	.recalc_rate = zynqmp_pll_recalc_rate,
287 	.set_rate = zynqmp_pll_set_rate,
288 };
289 
290 /**
291  * zynqmp_clk_register_pll() - Register PLL with the clock framework
292  * @name:		PLL name
293  * @clk_id:		Clock ID
294  * @parents:		Name of this clock's parents
295  * @num_parents:	Number of parents
296  * @nodes:		Clock topology node
297  *
298  * Return: clock hardware to the registered clock
299  */
300 struct clk_hw *zynqmp_clk_register_pll(const char *name, u32 clk_id,
301 				       const char * const *parents,
302 				       u8 num_parents,
303 				       const struct clock_topology *nodes)
304 {
305 	struct zynqmp_pll *pll;
306 	struct clk_hw *hw;
307 	struct clk_init_data init;
308 	int ret;
309 
310 	init.name = name;
311 	init.ops = &zynqmp_pll_ops;
312 	init.flags = nodes->flag;
313 	init.parent_names = parents;
314 	init.num_parents = 1;
315 
316 	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
317 	if (!pll)
318 		return ERR_PTR(-ENOMEM);
319 
320 	pll->hw.init = &init;
321 	pll->clk_id = clk_id;
322 
323 	hw = &pll->hw;
324 	ret = clk_hw_register(NULL, hw);
325 	if (ret) {
326 		kfree(pll);
327 		return ERR_PTR(ret);
328 	}
329 
330 	clk_hw_set_rate_range(hw, PS_PLL_VCO_MIN, PS_PLL_VCO_MAX);
331 	if (ret < 0)
332 		pr_err("%s:ERROR clk_set_rate_range failed %d\n", name, ret);
333 
334 	return hw;
335 }
336