xref: /linux/drivers/clk/pxa/clk-pxa25x.c (revision 18f90d372cf35b387663f1567de701e5393f6eb5)
1 /*
2  * Marvell PXA25x family clocks
3  *
4  * Copyright (C) 2014 Robert Jarzmik
5  *
6  * Heavily inspired from former arch/arm/mach-pxa/pxa25x.c.
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; version 2 of the License.
11  *
12  * For non-devicetree platforms. Once pxa is fully converted to devicetree, this
13  * should go away.
14  */
15 #include <linux/clk-provider.h>
16 #include <linux/clk.h>
17 #include <linux/clkdev.h>
18 #include <linux/io.h>
19 #include <linux/of.h>
20 #include <mach/pxa2xx-regs.h>
21 #include <mach/smemc.h>
22 
23 #include <dt-bindings/clock/pxa-clock.h>
24 #include "clk-pxa.h"
25 
26 #define KHz 1000
27 #define MHz (1000 * 1000)
28 
29 enum {
30 	PXA_CORE_RUN = 0,
31 	PXA_CORE_TURBO,
32 };
33 
34 #define PXA25x_CLKCFG(T)			\
35 	(CLKCFG_FCS |				\
36 	 ((T) ? CLKCFG_TURBO : 0))
37 #define PXA25x_CCCR(N2, M, L) (N2 << 7 | M << 5 | L)
38 
39 #define MDCNFG_DRAC2(mdcnfg)	(((mdcnfg) >> 21) & 0x3)
40 #define MDCNFG_DRAC0(mdcnfg)	(((mdcnfg) >> 5) & 0x3)
41 
42 /* Define the refresh period in mSec for the SDRAM and the number of rows */
43 #define SDRAM_TREF	64	/* standard 64ms SDRAM */
44 
45 /*
46  * Various clock factors driven by the CCCR register.
47  */
48 
49 /* Crystal Frequency to Memory Frequency Multiplier (L) */
50 static unsigned char L_clk_mult[32] = { 0, 27, 32, 36, 40, 45, 0, };
51 
52 /* Memory Frequency to Run Mode Frequency Multiplier (M) */
53 static unsigned char M_clk_mult[4] = { 0, 1, 2, 4 };
54 
55 /* Run Mode Frequency to Turbo Mode Frequency Multiplier (N) */
56 /* Note: we store the value N * 2 here. */
57 static unsigned char N2_clk_mult[8] = { 0, 0, 2, 3, 4, 0, 6, 0 };
58 
59 static const char * const get_freq_khz[] = {
60 	"core", "run", "cpll", "memory"
61 };
62 
63 static int get_sdram_rows(void)
64 {
65 	static int sdram_rows;
66 	unsigned int drac2 = 0, drac0 = 0;
67 	u32 mdcnfg;
68 
69 	if (sdram_rows)
70 		return sdram_rows;
71 
72 	mdcnfg = readl_relaxed(MDCNFG);
73 
74 	if (mdcnfg & (MDCNFG_DE2 | MDCNFG_DE3))
75 		drac2 = MDCNFG_DRAC2(mdcnfg);
76 
77 	if (mdcnfg & (MDCNFG_DE0 | MDCNFG_DE1))
78 		drac0 = MDCNFG_DRAC0(mdcnfg);
79 
80 	sdram_rows = 1 << (11 + max(drac0, drac2));
81 	return sdram_rows;
82 }
83 
84 static u32 mdrefr_dri(unsigned int freq_khz)
85 {
86 	u32 interval = freq_khz * SDRAM_TREF / get_sdram_rows();
87 
88 	return interval / 32;
89 }
90 
91 /*
92  * Get the clock frequency as reflected by CCCR and the turbo flag.
93  * We assume these values have been applied via a fcs.
94  * If info is not 0 we also display the current settings.
95  */
96 unsigned int pxa25x_get_clk_frequency_khz(int info)
97 {
98 	struct clk *clk;
99 	unsigned long clks[5];
100 	int i;
101 
102 	for (i = 0; i < ARRAY_SIZE(get_freq_khz); i++) {
103 		clk = clk_get(NULL, get_freq_khz[i]);
104 		if (IS_ERR(clk)) {
105 			clks[i] = 0;
106 		} else {
107 			clks[i] = clk_get_rate(clk);
108 			clk_put(clk);
109 		}
110 	}
111 
112 	if (info) {
113 		pr_info("Run Mode clock: %ld.%02ldMHz\n",
114 			clks[1] / 1000000, (clks[1] % 1000000) / 10000);
115 		pr_info("Turbo Mode clock: %ld.%02ldMHz\n",
116 			clks[2] / 1000000, (clks[2] % 1000000) / 10000);
117 		pr_info("Memory clock: %ld.%02ldMHz\n",
118 			clks[3] / 1000000, (clks[3] % 1000000) / 10000);
119 	}
120 
121 	return (unsigned int)clks[0] / KHz;
122 }
123 
124 static unsigned long clk_pxa25x_memory_get_rate(struct clk_hw *hw,
125 						unsigned long parent_rate)
126 {
127 	unsigned long cccr = readl(CCCR);
128 	unsigned int m = M_clk_mult[(cccr >> 5) & 0x03];
129 
130 	return parent_rate / m;
131 }
132 PARENTS(clk_pxa25x_memory) = { "run" };
133 RATE_RO_OPS(clk_pxa25x_memory, "memory");
134 
135 PARENTS(pxa25x_pbus95) = { "ppll_95_85mhz", "ppll_95_85mhz" };
136 PARENTS(pxa25x_pbus147) = { "ppll_147_46mhz", "ppll_147_46mhz" };
137 PARENTS(pxa25x_osc3) = { "osc_3_6864mhz", "osc_3_6864mhz" };
138 
139 #define PXA25X_CKEN(dev_id, con_id, parents, mult, div,			\
140 		    bit, is_lp, flags)					\
141 	PXA_CKEN(dev_id, con_id, bit, parents, mult, div, mult, div,	\
142 		 is_lp,  CKEN, CKEN_ ## bit, flags)
143 #define PXA25X_PBUS95_CKEN(dev_id, con_id, bit, mult_hp, div_hp, delay)	\
144 	PXA25X_CKEN(dev_id, con_id, pxa25x_pbus95_parents, mult_hp,	\
145 		    div_hp, bit, NULL, 0)
146 #define PXA25X_PBUS147_CKEN(dev_id, con_id, bit, mult_hp, div_hp, delay)\
147 	PXA25X_CKEN(dev_id, con_id, pxa25x_pbus147_parents, mult_hp,	\
148 		    div_hp, bit, NULL, 0)
149 #define PXA25X_OSC3_CKEN(dev_id, con_id, bit, mult_hp, div_hp, delay)	\
150 	PXA25X_CKEN(dev_id, con_id, pxa25x_osc3_parents, mult_hp,	\
151 		    div_hp, bit, NULL, 0)
152 
153 #define PXA25X_CKEN_1RATE(dev_id, con_id, bit, parents, delay)		\
154 	PXA_CKEN_1RATE(dev_id, con_id, bit, parents,			\
155 		       CKEN, CKEN_ ## bit, 0)
156 #define PXA25X_CKEN_1RATE_AO(dev_id, con_id, bit, parents, delay)	\
157 	PXA_CKEN_1RATE(dev_id, con_id, bit, parents,			\
158 		       CKEN, CKEN_ ## bit, CLK_IGNORE_UNUSED)
159 
160 static struct desc_clk_cken pxa25x_clocks[] __initdata = {
161 	PXA25X_PBUS95_CKEN("pxa2xx-mci.0", NULL, MMC, 1, 5, 0),
162 	PXA25X_PBUS95_CKEN("pxa2xx-i2c.0", NULL, I2C, 1, 3, 0),
163 	PXA25X_PBUS95_CKEN("pxa2xx-ir", "FICPCLK", FICP, 1, 2, 0),
164 	PXA25X_PBUS95_CKEN("pxa25x-udc", NULL, USB, 1, 2, 5),
165 	PXA25X_PBUS147_CKEN("pxa2xx-uart.0", NULL, FFUART, 1, 10, 1),
166 	PXA25X_PBUS147_CKEN("pxa2xx-uart.1", NULL, BTUART, 1, 10, 1),
167 	PXA25X_PBUS147_CKEN("pxa2xx-uart.2", NULL, STUART, 1, 10, 1),
168 	PXA25X_PBUS147_CKEN("pxa2xx-uart.3", NULL, HWUART, 1, 10, 1),
169 	PXA25X_PBUS147_CKEN("pxa2xx-i2s", NULL, I2S, 1, 10, 0),
170 	PXA25X_PBUS147_CKEN(NULL, "AC97CLK", AC97, 1, 12, 0),
171 	PXA25X_OSC3_CKEN("pxa25x-ssp.0", NULL, SSP, 1, 1, 0),
172 	PXA25X_OSC3_CKEN("pxa25x-nssp.1", NULL, NSSP, 1, 1, 0),
173 	PXA25X_OSC3_CKEN("pxa25x-nssp.2", NULL, ASSP, 1, 1, 0),
174 	PXA25X_OSC3_CKEN("pxa25x-pwm.0", NULL, PWM0, 1, 1, 0),
175 	PXA25X_OSC3_CKEN("pxa25x-pwm.1", NULL, PWM1, 1, 1, 0),
176 
177 	PXA25X_CKEN_1RATE("pxa2xx-fb", NULL, LCD, clk_pxa25x_memory_parents, 0),
178 	PXA25X_CKEN_1RATE_AO("pxa2xx-pcmcia", NULL, MEMC,
179 			     clk_pxa25x_memory_parents, 0),
180 };
181 
182 /*
183  * In this table, PXA25x_CCCR(N2, M, L) has the following meaning, where :
184  *   - freq_cpll = n * m * L * 3.6864 MHz
185  *   - n = N2 / 2
186  *   - m = 2^(M - 1), where 1 <= M <= 3
187  *   - l = L_clk_mult[L], ie. { 0, 27, 32, 36, 40, 45, 0, }[L]
188  */
189 static struct pxa2xx_freq pxa25x_freqs[] = {
190 	/* CPU  MEMBUS  CCCR                  DIV2 CCLKCFG      */
191 	{ 99532800, 99500, PXA25x_CCCR(2,  1, 1),  1, PXA25x_CLKCFG(1)},
192 	{199065600, 99500, PXA25x_CCCR(4,  1, 1),  0, PXA25x_CLKCFG(1)},
193 	{298598400, 99500, PXA25x_CCCR(3,  2, 1),  0, PXA25x_CLKCFG(1)},
194 	{398131200, 99500, PXA25x_CCCR(4,  2, 1),  0, PXA25x_CLKCFG(1)},
195 };
196 
197 static u8 clk_pxa25x_core_get_parent(struct clk_hw *hw)
198 {
199 	unsigned long clkcfg;
200 	unsigned int t;
201 
202 	asm("mrc\tp14, 0, %0, c6, c0, 0" : "=r" (clkcfg));
203 	t  = clkcfg & (1 << 0);
204 	if (t)
205 		return PXA_CORE_TURBO;
206 	return PXA_CORE_RUN;
207 }
208 
209 static int clk_pxa25x_core_set_parent(struct clk_hw *hw, u8 index)
210 {
211 	if (index > PXA_CORE_TURBO)
212 		return -EINVAL;
213 
214 	pxa2xx_core_turbo_switch(index == PXA_CORE_TURBO);
215 
216 	return 0;
217 }
218 
219 static int clk_pxa25x_core_determine_rate(struct clk_hw *hw,
220 					  struct clk_rate_request *req)
221 {
222 	return __clk_mux_determine_rate(hw, req);
223 }
224 
225 PARENTS(clk_pxa25x_core) = { "run", "cpll" };
226 MUX_OPS(clk_pxa25x_core, "core", CLK_SET_RATE_PARENT);
227 
228 static unsigned long clk_pxa25x_run_get_rate(struct clk_hw *hw,
229 					     unsigned long parent_rate)
230 {
231 	unsigned long cccr = readl(CCCR);
232 	unsigned int n2 = N2_clk_mult[(cccr >> 7) & 0x07];
233 
234 	return (parent_rate / n2) * 2;
235 }
236 PARENTS(clk_pxa25x_run) = { "cpll" };
237 RATE_RO_OPS(clk_pxa25x_run, "run");
238 
239 static unsigned long clk_pxa25x_cpll_get_rate(struct clk_hw *hw,
240 	unsigned long parent_rate)
241 {
242 	unsigned long clkcfg, cccr = readl(CCCR);
243 	unsigned int l, m, n2, t;
244 
245 	asm("mrc\tp14, 0, %0, c6, c0, 0" : "=r" (clkcfg));
246 	t = clkcfg & (1 << 0);
247 	l  =  L_clk_mult[(cccr >> 0) & 0x1f];
248 	m = M_clk_mult[(cccr >> 5) & 0x03];
249 	n2 = N2_clk_mult[(cccr >> 7) & 0x07];
250 
251 	return m * l * n2 * parent_rate / 2;
252 }
253 
254 static int clk_pxa25x_cpll_determine_rate(struct clk_hw *hw,
255 					  struct clk_rate_request *req)
256 {
257 	return pxa2xx_determine_rate(req, pxa25x_freqs,
258 				     ARRAY_SIZE(pxa25x_freqs));
259 }
260 
261 static int clk_pxa25x_cpll_set_rate(struct clk_hw *hw, unsigned long rate,
262 				    unsigned long parent_rate)
263 {
264 	int i;
265 
266 	pr_debug("%s(rate=%lu parent_rate=%lu)\n", __func__, rate, parent_rate);
267 	for (i = 0; i < ARRAY_SIZE(pxa25x_freqs); i++)
268 		if (pxa25x_freqs[i].cpll == rate)
269 			break;
270 
271 	if (i >= ARRAY_SIZE(pxa25x_freqs))
272 		return -EINVAL;
273 
274 	pxa2xx_cpll_change(&pxa25x_freqs[i], mdrefr_dri, MDREFR, CCCR);
275 
276 	return 0;
277 }
278 PARENTS(clk_pxa25x_cpll) = { "osc_3_6864mhz" };
279 RATE_OPS(clk_pxa25x_cpll, "cpll");
280 
281 static void __init pxa25x_register_core(void)
282 {
283 	clkdev_pxa_register(CLK_NONE, "cpll", NULL,
284 			    clk_register_clk_pxa25x_cpll());
285 	clkdev_pxa_register(CLK_NONE, "run", NULL,
286 			    clk_register_clk_pxa25x_run());
287 	clkdev_pxa_register(CLK_CORE, "core", NULL,
288 			    clk_register_clk_pxa25x_core());
289 }
290 
291 static void __init pxa25x_register_plls(void)
292 {
293 	clk_register_fixed_rate(NULL, "osc_3_6864mhz", NULL,
294 				CLK_GET_RATE_NOCACHE, 3686400);
295 	clkdev_pxa_register(CLK_OSC32k768, "osc_32_768khz", NULL,
296 			    clk_register_fixed_rate(NULL, "osc_32_768khz", NULL,
297 						    CLK_GET_RATE_NOCACHE,
298 						    32768));
299 	clk_register_fixed_rate(NULL, "clk_dummy", NULL, 0, 0);
300 	clk_register_fixed_factor(NULL, "ppll_95_85mhz", "osc_3_6864mhz",
301 				  0, 26, 1);
302 	clk_register_fixed_factor(NULL, "ppll_147_46mhz", "osc_3_6864mhz",
303 				  0, 40, 1);
304 }
305 
306 static void __init pxa25x_base_clocks_init(void)
307 {
308 	pxa25x_register_plls();
309 	pxa25x_register_core();
310 	clkdev_pxa_register(CLK_NONE, "system_bus", NULL,
311 			    clk_register_clk_pxa25x_memory());
312 }
313 
314 #define DUMMY_CLK(_con_id, _dev_id, _parent) \
315 	{ .con_id = _con_id, .dev_id = _dev_id, .parent = _parent }
316 struct dummy_clk {
317 	const char *con_id;
318 	const char *dev_id;
319 	const char *parent;
320 };
321 static struct dummy_clk dummy_clks[] __initdata = {
322 	DUMMY_CLK(NULL, "pxa25x-gpio", "osc_32_768khz"),
323 	DUMMY_CLK(NULL, "pxa26x-gpio", "osc_32_768khz"),
324 	DUMMY_CLK("GPIO11_CLK", NULL, "osc_3_6864mhz"),
325 	DUMMY_CLK("GPIO12_CLK", NULL, "osc_32_768khz"),
326 	DUMMY_CLK(NULL, "sa1100-rtc", "osc_32_768khz"),
327 	DUMMY_CLK("OSTIMER0", NULL, "osc_3_6864mhz"),
328 	DUMMY_CLK("UARTCLK", "pxa2xx-ir", "STUART"),
329 };
330 
331 static void __init pxa25x_dummy_clocks_init(void)
332 {
333 	struct clk *clk;
334 	struct dummy_clk *d;
335 	const char *name;
336 	int i;
337 
338 	/*
339 	 * All pinctrl logic has been wiped out of the clock driver, especially
340 	 * for gpio11 and gpio12 outputs. Machine code should ensure proper pin
341 	 * control (ie. pxa2xx_mfp_config() invocation).
342 	 */
343 	for (i = 0; i < ARRAY_SIZE(dummy_clks); i++) {
344 		d = &dummy_clks[i];
345 		name = d->dev_id ? d->dev_id : d->con_id;
346 		clk = clk_register_fixed_factor(NULL, name, d->parent, 0, 1, 1);
347 		clk_register_clkdev(clk, d->con_id, d->dev_id);
348 	}
349 }
350 
351 int __init pxa25x_clocks_init(void)
352 {
353 	pxa25x_base_clocks_init();
354 	pxa25x_dummy_clocks_init();
355 	return clk_pxa_cken_init(pxa25x_clocks, ARRAY_SIZE(pxa25x_clocks));
356 }
357 
358 static void __init pxa25x_dt_clocks_init(struct device_node *np)
359 {
360 	pxa25x_clocks_init();
361 	clk_pxa_dt_common_init(np);
362 }
363 CLK_OF_DECLARE(pxa25x_clks, "marvell,pxa250-core-clocks",
364 	       pxa25x_dt_clocks_init);
365