xref: /openbmc/linux/drivers/mfd/db8500-prcmu.c (revision 650c2a21)
1 /*
2  * Copyright (C) STMicroelectronics 2009
3  * Copyright (C) ST-Ericsson SA 2010
4  *
5  * License Terms: GNU General Public License v2
6  * Author: Kumar Sanghvi <kumar.sanghvi@stericsson.com>
7  * Author: Sundar Iyer <sundar.iyer@stericsson.com>
8  * Author: Mattias Nilsson <mattias.i.nilsson@stericsson.com>
9  *
10  * U8500 PRCM Unit interface driver
11  *
12  */
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/errno.h>
16 #include <linux/err.h>
17 #include <linux/io.h>
18 #include <linux/mutex.h>
19 #include <linux/completion.h>
20 #include <linux/jiffies.h>
21 #include <linux/bitops.h>
22 #include <linux/interrupt.h>
23 #include <linux/mfd/db8500-prcmu.h>
24 
25 #include <mach/hardware.h>
26 
27 #include "db8500-prcmu-regs.h"
28 
29 /* Global var to runtime determine TCDM base for v2 or v1 */
30 static __iomem void *tcdm_base;
31 
32 #define _MBOX_HEADER		(tcdm_base + 0xFE8)
33 #define MBOX_HEADER_REQ_MB0	(_MBOX_HEADER + 0x0)
34 
35 #define REQ_MB1 (tcdm_base + 0xFD0)
36 #define REQ_MB5 (tcdm_base + 0xE44)
37 
38 #define REQ_MB1_ARMOPP		(REQ_MB1 + 0x0)
39 #define REQ_MB1_APEOPP		(REQ_MB1 + 0x1)
40 #define REQ_MB1_BOOSTOPP	(REQ_MB1 + 0x2)
41 
42 #define ACK_MB1 (tcdm_base + 0xE04)
43 #define ACK_MB5 (tcdm_base + 0xDF4)
44 
45 #define ACK_MB1_CURR_ARMOPP		(ACK_MB1 + 0x0)
46 #define ACK_MB1_CURR_APEOPP		(ACK_MB1 + 0x1)
47 
48 #define REQ_MB5_I2C_SLAVE_OP (REQ_MB5)
49 #define REQ_MB5_I2C_HW_BITS (REQ_MB5 + 1)
50 #define REQ_MB5_I2C_REG (REQ_MB5 + 2)
51 #define REQ_MB5_I2C_VAL (REQ_MB5 + 3)
52 
53 #define ACK_MB5_I2C_STATUS (ACK_MB5 + 1)
54 #define ACK_MB5_I2C_VAL (ACK_MB5 + 3)
55 
56 #define PRCM_AVS_VARM_MAX_OPP		(tcdm_base + 0x2E4)
57 #define PRCM_AVS_ISMODEENABLE		7
58 #define PRCM_AVS_ISMODEENABLE_MASK	(1 << PRCM_AVS_ISMODEENABLE)
59 
60 #define I2C_WRITE(slave) \
61 	(((slave) << 1) | (cpu_is_u8500v2() ? BIT(6) : 0))
62 #define I2C_READ(slave) \
63 	(((slave) << 1) | (cpu_is_u8500v2() ? BIT(6) : 0) | BIT(0))
64 #define I2C_STOP_EN BIT(3)
65 
66 enum mb1_h {
67 	MB1H_ARM_OPP = 1,
68 	MB1H_APE_OPP,
69 	MB1H_ARM_APE_OPP,
70 };
71 
72 static struct {
73 	struct mutex lock;
74 	struct completion work;
75 	struct {
76 		u8 arm_opp;
77 		u8 ape_opp;
78 		u8 arm_status;
79 		u8 ape_status;
80 	} ack;
81 } mb1_transfer;
82 
83 enum ack_mb5_status {
84 	I2C_WR_OK = 0x01,
85 	I2C_RD_OK = 0x02,
86 };
87 
88 #define MBOX_BIT BIT
89 #define NUM_MBOX 8
90 
91 static struct {
92 	struct mutex lock;
93 	struct completion work;
94 	bool failed;
95 	struct {
96 		u8 status;
97 		u8 value;
98 	} ack;
99 } mb5_transfer;
100 
101 /**
102  * prcmu_abb_read() - Read register value(s) from the ABB.
103  * @slave:	The I2C slave address.
104  * @reg:	The (start) register address.
105  * @value:	The read out value(s).
106  * @size:	The number of registers to read.
107  *
108  * Reads register value(s) from the ABB.
109  * @size has to be 1 for the current firmware version.
110  */
111 int prcmu_abb_read(u8 slave, u8 reg, u8 *value, u8 size)
112 {
113 	int r;
114 
115 	if (size != 1)
116 		return -EINVAL;
117 
118 	r = mutex_lock_interruptible(&mb5_transfer.lock);
119 	if (r)
120 		return r;
121 
122 	while (readl(PRCM_MBOX_CPU_VAL) & MBOX_BIT(5))
123 		cpu_relax();
124 
125 	writeb(I2C_READ(slave), REQ_MB5_I2C_SLAVE_OP);
126 	writeb(I2C_STOP_EN, REQ_MB5_I2C_HW_BITS);
127 	writeb(reg, REQ_MB5_I2C_REG);
128 
129 	writel(MBOX_BIT(5), PRCM_MBOX_CPU_SET);
130 	if (!wait_for_completion_timeout(&mb5_transfer.work,
131 			msecs_to_jiffies(500))) {
132 		pr_err("prcmu: prcmu_abb_read timed out.\n");
133 		r = -EIO;
134 		goto unlock_and_return;
135 	}
136 	r = ((mb5_transfer.ack.status == I2C_RD_OK) ? 0 : -EIO);
137 	if (!r)
138 		*value = mb5_transfer.ack.value;
139 
140 unlock_and_return:
141 	mutex_unlock(&mb5_transfer.lock);
142 	return r;
143 }
144 EXPORT_SYMBOL(prcmu_abb_read);
145 
146 /**
147  * prcmu_abb_write() - Write register value(s) to the ABB.
148  * @slave:	The I2C slave address.
149  * @reg:	The (start) register address.
150  * @value:	The value(s) to write.
151  * @size:	The number of registers to write.
152  *
153  * Reads register value(s) from the ABB.
154  * @size has to be 1 for the current firmware version.
155  */
156 int prcmu_abb_write(u8 slave, u8 reg, u8 *value, u8 size)
157 {
158 	int r;
159 
160 	if (size != 1)
161 		return -EINVAL;
162 
163 	r = mutex_lock_interruptible(&mb5_transfer.lock);
164 	if (r)
165 		return r;
166 
167 
168 	while (readl(PRCM_MBOX_CPU_VAL) & MBOX_BIT(5))
169 		cpu_relax();
170 
171 	writeb(I2C_WRITE(slave), REQ_MB5_I2C_SLAVE_OP);
172 	writeb(I2C_STOP_EN, REQ_MB5_I2C_HW_BITS);
173 	writeb(reg, REQ_MB5_I2C_REG);
174 	writeb(*value, REQ_MB5_I2C_VAL);
175 
176 	writel(MBOX_BIT(5), PRCM_MBOX_CPU_SET);
177 	if (!wait_for_completion_timeout(&mb5_transfer.work,
178 			msecs_to_jiffies(500))) {
179 		pr_err("prcmu: prcmu_abb_write timed out.\n");
180 		r = -EIO;
181 		goto unlock_and_return;
182 	}
183 	r = ((mb5_transfer.ack.status == I2C_WR_OK) ? 0 : -EIO);
184 
185 unlock_and_return:
186 	mutex_unlock(&mb5_transfer.lock);
187 	return r;
188 }
189 EXPORT_SYMBOL(prcmu_abb_write);
190 
191 static int set_ape_cpu_opps(u8 header, enum prcmu_ape_opp ape_opp,
192 			    enum prcmu_cpu_opp cpu_opp)
193 {
194 	bool do_ape;
195 	bool do_arm;
196 	int err = 0;
197 
198 	do_ape = ((header == MB1H_APE_OPP) || (header == MB1H_ARM_APE_OPP));
199 	do_arm = ((header == MB1H_ARM_OPP) || (header == MB1H_ARM_APE_OPP));
200 
201 	mutex_lock(&mb1_transfer.lock);
202 
203 	while (readl(PRCM_MBOX_CPU_VAL) & MBOX_BIT(1))
204 		cpu_relax();
205 
206 	writeb(0, MBOX_HEADER_REQ_MB0);
207 	writeb(cpu_opp, REQ_MB1_ARMOPP);
208 	writeb(ape_opp, REQ_MB1_APEOPP);
209 	writeb(0, REQ_MB1_BOOSTOPP);
210 	writel(MBOX_BIT(1), PRCM_MBOX_CPU_SET);
211 	wait_for_completion(&mb1_transfer.work);
212 	if ((do_ape) && (mb1_transfer.ack.ape_status != 0))
213 		err = -EIO;
214 	if ((do_arm) && (mb1_transfer.ack.arm_status != 0))
215 		err = -EIO;
216 
217 	mutex_unlock(&mb1_transfer.lock);
218 
219 	return err;
220 }
221 
222 /**
223  * prcmu_set_ape_opp() - Set the OPP of the APE.
224  * @opp:	The OPP to set.
225  *
226  * This function sets the OPP of the APE.
227  */
228 int prcmu_set_ape_opp(enum prcmu_ape_opp opp)
229 {
230 	return set_ape_cpu_opps(MB1H_APE_OPP, opp, APE_OPP_NO_CHANGE);
231 }
232 EXPORT_SYMBOL(prcmu_set_ape_opp);
233 
234 /**
235  * prcmu_set_cpu_opp() - Set the OPP of the CPU.
236  * @opp:	The OPP to set.
237  *
238  * This function sets the OPP of the CPU.
239  */
240 int prcmu_set_cpu_opp(enum prcmu_cpu_opp opp)
241 {
242 	return set_ape_cpu_opps(MB1H_ARM_OPP, CPU_OPP_NO_CHANGE, opp);
243 }
244 EXPORT_SYMBOL(prcmu_set_cpu_opp);
245 
246 /**
247  * prcmu_set_ape_cpu_opps() - Set the OPPs of the APE and the CPU.
248  * @ape_opp:	The APE OPP to set.
249  * @cpu_opp:	The CPU OPP to set.
250  *
251  * This function sets the OPPs of the APE and the CPU.
252  */
253 int prcmu_set_ape_cpu_opps(enum prcmu_ape_opp ape_opp,
254 			   enum prcmu_cpu_opp cpu_opp)
255 {
256 	return set_ape_cpu_opps(MB1H_ARM_APE_OPP, ape_opp, cpu_opp);
257 }
258 EXPORT_SYMBOL(prcmu_set_ape_cpu_opps);
259 
260 /**
261  * prcmu_get_ape_opp() - Get the OPP of the APE.
262  *
263  * This function gets the OPP of the APE.
264  */
265 enum prcmu_ape_opp prcmu_get_ape_opp(void)
266 {
267 	return readb(ACK_MB1_CURR_APEOPP);
268 }
269 EXPORT_SYMBOL(prcmu_get_ape_opp);
270 
271 /**
272  * prcmu_get_cpu_opp() - Get the OPP of the CPU.
273  *
274  * This function gets the OPP of the CPU. The OPP is specified in %%.
275  * PRCMU_OPP_EXT is a special OPP value, not specified in %%.
276  */
277 int prcmu_get_cpu_opp(void)
278 {
279 	return readb(ACK_MB1_CURR_ARMOPP);
280 }
281 EXPORT_SYMBOL(prcmu_get_cpu_opp);
282 
283 bool prcmu_has_arm_maxopp(void)
284 {
285 	return (readb(PRCM_AVS_VARM_MAX_OPP) & PRCM_AVS_ISMODEENABLE_MASK)
286 		== PRCM_AVS_ISMODEENABLE_MASK;
287 }
288 
289 static void read_mailbox_0(void)
290 {
291 	writel(MBOX_BIT(0), PRCM_ARM_IT1_CLEAR);
292 }
293 
294 static void read_mailbox_1(void)
295 {
296 	mb1_transfer.ack.arm_opp = readb(ACK_MB1_CURR_ARMOPP);
297 	mb1_transfer.ack.ape_opp = readb(ACK_MB1_CURR_APEOPP);
298 	complete(&mb1_transfer.work);
299 	writel(MBOX_BIT(1), PRCM_ARM_IT1_CLEAR);
300 }
301 
302 static void read_mailbox_2(void)
303 {
304 	writel(MBOX_BIT(2), PRCM_ARM_IT1_CLEAR);
305 }
306 
307 static void read_mailbox_3(void)
308 {
309 	writel(MBOX_BIT(3), PRCM_ARM_IT1_CLEAR);
310 }
311 
312 static void read_mailbox_4(void)
313 {
314 	writel(MBOX_BIT(4), PRCM_ARM_IT1_CLEAR);
315 }
316 
317 static void read_mailbox_5(void)
318 {
319 	mb5_transfer.ack.status = readb(ACK_MB5_I2C_STATUS);
320 	mb5_transfer.ack.value = readb(ACK_MB5_I2C_VAL);
321 	complete(&mb5_transfer.work);
322 	writel(MBOX_BIT(5), PRCM_ARM_IT1_CLEAR);
323 }
324 
325 static void read_mailbox_6(void)
326 {
327 	writel(MBOX_BIT(6), PRCM_ARM_IT1_CLEAR);
328 }
329 
330 static void read_mailbox_7(void)
331 {
332 	writel(MBOX_BIT(7), PRCM_ARM_IT1_CLEAR);
333 }
334 
335 static void (* const read_mailbox[NUM_MBOX])(void) = {
336 	read_mailbox_0,
337 	read_mailbox_1,
338 	read_mailbox_2,
339 	read_mailbox_3,
340 	read_mailbox_4,
341 	read_mailbox_5,
342 	read_mailbox_6,
343 	read_mailbox_7
344 };
345 
346 static irqreturn_t prcmu_irq_handler(int irq, void *data)
347 {
348 	u32 bits;
349 	u8 n;
350 
351 	bits = (readl(PRCM_ARM_IT1_VAL) & (MBOX_BIT(NUM_MBOX) - 1));
352 	if (unlikely(!bits))
353 		return IRQ_NONE;
354 
355 	for (n = 0; bits; n++) {
356 		if (bits & MBOX_BIT(n)) {
357 			bits -= MBOX_BIT(n);
358 			read_mailbox[n]();
359 		}
360 	}
361 	return IRQ_HANDLED;
362 }
363 
364 void __init prcmu_early_init(void)
365 {
366 	if (cpu_is_u8500v11() || cpu_is_u8500ed()) {
367 		tcdm_base = __io_address(U8500_PRCMU_TCDM_BASE_V1);
368 	} else if (cpu_is_u8500v2()) {
369 		tcdm_base = __io_address(U8500_PRCMU_TCDM_BASE);
370 	} else {
371 		pr_err("prcmu: Unsupported chip version\n");
372 		BUG();
373 	}
374 }
375 
376 static int __init prcmu_init(void)
377 {
378 	if (cpu_is_u8500ed()) {
379 		pr_err("prcmu: Unsupported chip version\n");
380 		return 0;
381 	}
382 
383 	mutex_init(&mb1_transfer.lock);
384 	init_completion(&mb1_transfer.work);
385 	mutex_init(&mb5_transfer.lock);
386 	init_completion(&mb5_transfer.work);
387 
388 	/* Clean up the mailbox interrupts after pre-kernel code. */
389 	writel((MBOX_BIT(NUM_MBOX) - 1), PRCM_ARM_IT1_CLEAR);
390 
391 	return request_irq(IRQ_DB8500_PRCMU1, prcmu_irq_handler, 0,
392 			   "prcmu", NULL);
393 }
394 
395 arch_initcall(prcmu_init);
396