2 * (C) Copyright 2003-2004
3 * Humboldt Solutions Ltd, adrian@humboldt.co.uk.
5 * This is a combined i2c adapter and algorithm driver for the
6 * MPC107/Tsi107 PowerPC northbridge and processors that include
7 * the same I2C unit (8240, 8245, 85xx).
11 * This file is licensed under the terms of the GNU General Public
12 * License version 2. This program is licensed "as is" without any
13 * warranty of any kind, whether express or implied.
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/sched.h>
19 #include <linux/init.h>
20 #include <linux/of_platform.h>
21 #include <linux/of_i2c.h>
22 #include <linux/slab.h>
25 #include <linux/fsl_devices.h>
26 #include <linux/i2c.h>
27 #include <linux/interrupt.h>
28 #include <linux/delay.h>
30 #include <asm/mpc52xx.h>
31 #include <sysdev/fsl_soc.h>
33 #define DRV_NAME "mpc-i2c"
35 #define MPC_I2C_CLOCK_LEGACY 0
36 #define MPC_I2C_CLOCK_PRESERVE (~0U)
38 #define MPC_I2C_FDR 0x04
39 #define MPC_I2C_CR 0x08
40 #define MPC_I2C_SR 0x0c
41 #define MPC_I2C_DR 0x10
42 #define MPC_I2C_DFSRR 0x14
63 wait_queue_head_t queue;
64 struct i2c_adapter adap;
69 struct mpc_i2c_divider {
71 u16 fdr; /* including dfsrr */
75 void (*setup)(struct device_node *node, struct mpc_i2c *i2c,
76 u32 clock, u32 prescaler);
80 static inline void writeccr(struct mpc_i2c *i2c, u32 x)
82 writeb(x, i2c->base + MPC_I2C_CR);
85 static irqreturn_t mpc_i2c_isr(int irq, void *dev_id)
87 struct mpc_i2c *i2c = dev_id;
88 if (readb(i2c->base + MPC_I2C_SR) & CSR_MIF) {
89 /* Read again to allow register to stabilise */
90 i2c->interrupt = readb(i2c->base + MPC_I2C_SR);
91 writeb(0, i2c->base + MPC_I2C_SR);
97 /* Sometimes 9th clock pulse isn't generated, and slave doesn't release
98 * the bus, because it wants to send ACK.
99 * Following sequence of enabling/disabling and sending start/stop generates
100 * the 9 pulses, so it's all OK.
102 static void mpc_i2c_fixup(struct mpc_i2c *i2c)
105 u32 delay_val = 1000000 / i2c->real_clk + 1;
110 for (k = 9; k; k--) {
112 writeccr(i2c, CCR_MSTA | CCR_MTX | CCR_MEN);
114 writeccr(i2c, CCR_MEN);
115 udelay(delay_val << 1);
119 static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing)
121 unsigned long orig_jiffies = jiffies;
126 while (!(readb(i2c->base + MPC_I2C_SR) & CSR_MIF)) {
128 if (time_after(jiffies, orig_jiffies + timeout)) {
129 dev_dbg(i2c->dev, "timeout\n");
135 x = readb(i2c->base + MPC_I2C_SR);
136 writeb(0, i2c->base + MPC_I2C_SR);
139 result = wait_event_timeout(i2c->queue,
140 (i2c->interrupt & CSR_MIF), timeout);
142 if (unlikely(!(i2c->interrupt & CSR_MIF))) {
143 dev_dbg(i2c->dev, "wait timeout\n");
155 if (!(x & CSR_MCF)) {
156 dev_dbg(i2c->dev, "unfinished\n");
161 dev_dbg(i2c->dev, "MAL\n");
165 if (writing && (x & CSR_RXAK)) {
166 dev_dbg(i2c->dev, "No RXAK\n");
168 writeccr(i2c, CCR_MEN);
174 #if defined(CONFIG_PPC_MPC52xx) || defined(CONFIG_PPC_MPC512x)
175 static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] __devinitconst = {
176 {20, 0x20}, {22, 0x21}, {24, 0x22}, {26, 0x23},
177 {28, 0x24}, {30, 0x01}, {32, 0x25}, {34, 0x02},
178 {36, 0x26}, {40, 0x27}, {44, 0x04}, {48, 0x28},
179 {52, 0x63}, {56, 0x29}, {60, 0x41}, {64, 0x2a},
180 {68, 0x07}, {72, 0x2b}, {80, 0x2c}, {88, 0x09},
181 {96, 0x2d}, {104, 0x0a}, {112, 0x2e}, {120, 0x81},
182 {128, 0x2f}, {136, 0x47}, {144, 0x0c}, {160, 0x30},
183 {176, 0x49}, {192, 0x31}, {208, 0x4a}, {224, 0x32},
184 {240, 0x0f}, {256, 0x33}, {272, 0x87}, {288, 0x10},
185 {320, 0x34}, {352, 0x89}, {384, 0x35}, {416, 0x8a},
186 {448, 0x36}, {480, 0x13}, {512, 0x37}, {576, 0x14},
187 {640, 0x38}, {768, 0x39}, {896, 0x3a}, {960, 0x17},
188 {1024, 0x3b}, {1152, 0x18}, {1280, 0x3c}, {1536, 0x3d},
189 {1792, 0x3e}, {1920, 0x1b}, {2048, 0x3f}, {2304, 0x1c},
190 {2560, 0x1d}, {3072, 0x1e}, {3584, 0x7e}, {3840, 0x1f},
191 {4096, 0x7f}, {4608, 0x5c}, {5120, 0x5d}, {6144, 0x5e},
192 {7168, 0xbe}, {7680, 0x5f}, {8192, 0xbf}, {9216, 0x9c},
193 {10240, 0x9d}, {12288, 0x9e}, {15360, 0x9f}
196 static int __devinit mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock,
197 int prescaler, u32 *real_clk)
199 const struct mpc_i2c_divider *div = NULL;
200 unsigned int pvr = mfspr(SPRN_PVR);
204 if (clock == MPC_I2C_CLOCK_LEGACY) {
205 /* see below - default fdr = 0x3f -> div = 2048 */
206 *real_clk = mpc5xxx_get_bus_frequency(node) / 2048;
210 /* Determine divider value */
211 divider = mpc5xxx_get_bus_frequency(node) / clock;
214 * We want to choose an FDR/DFSR that generates an I2C bus speed that
215 * is equal to or lower than the requested speed.
217 for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_52xx); i++) {
218 div = &mpc_i2c_dividers_52xx[i];
219 /* Old MPC5200 rev A CPUs do not support the high bits */
220 if (div->fdr & 0xc0 && pvr == 0x80822011)
222 if (div->divider >= divider)
226 *real_clk = mpc5xxx_get_bus_frequency(node) / div->divider;
227 return (int)div->fdr;
230 static void __devinit mpc_i2c_setup_52xx(struct device_node *node,
232 u32 clock, u32 prescaler)
236 if (clock == MPC_I2C_CLOCK_PRESERVE) {
237 dev_dbg(i2c->dev, "using fdr %d\n",
238 readb(i2c->base + MPC_I2C_FDR));
242 ret = mpc_i2c_get_fdr_52xx(node, clock, prescaler, &i2c->real_clk);
243 fdr = (ret >= 0) ? ret : 0x3f; /* backward compatibility */
245 writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
248 dev_info(i2c->dev, "clock %u Hz (fdr=%d)\n", i2c->real_clk,
251 #else /* !(CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x) */
252 static void __devinit mpc_i2c_setup_52xx(struct device_node *node,
254 u32 clock, u32 prescaler)
257 #endif /* CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x */
259 #ifdef CONFIG_PPC_MPC512x
260 static void __devinit mpc_i2c_setup_512x(struct device_node *node,
262 u32 clock, u32 prescaler)
264 struct device_node *node_ctrl;
269 /* Enable I2C interrupts for mpc5121 */
270 node_ctrl = of_find_compatible_node(NULL, NULL,
271 "fsl,mpc5121-i2c-ctrl");
273 ctrl = of_iomap(node_ctrl, 0);
275 /* Interrupt enable bits for i2c-0/1/2: bit 24/26/28 */
276 pval = of_get_property(node, "reg", NULL);
277 idx = (*pval & 0xff) / 0x20;
278 setbits32(ctrl, 1 << (24 + idx * 2));
281 of_node_put(node_ctrl);
284 /* The clock setup for the 52xx works also fine for the 512x */
285 mpc_i2c_setup_52xx(node, i2c, clock, prescaler);
287 #else /* CONFIG_PPC_MPC512x */
288 static void __devinit mpc_i2c_setup_512x(struct device_node *node,
290 u32 clock, u32 prescaler)
293 #endif /* CONFIG_PPC_MPC512x */
295 #ifdef CONFIG_FSL_SOC
296 static const struct mpc_i2c_divider mpc_i2c_dividers_8xxx[] __devinitconst = {
297 {160, 0x0120}, {192, 0x0121}, {224, 0x0122}, {256, 0x0123},
298 {288, 0x0100}, {320, 0x0101}, {352, 0x0601}, {384, 0x0102},
299 {416, 0x0602}, {448, 0x0126}, {480, 0x0103}, {512, 0x0127},
300 {544, 0x0b03}, {576, 0x0104}, {608, 0x1603}, {640, 0x0105},
301 {672, 0x2003}, {704, 0x0b05}, {736, 0x2b03}, {768, 0x0106},
302 {800, 0x3603}, {832, 0x0b06}, {896, 0x012a}, {960, 0x0107},
303 {1024, 0x012b}, {1088, 0x1607}, {1152, 0x0108}, {1216, 0x2b07},
304 {1280, 0x0109}, {1408, 0x1609}, {1536, 0x010a}, {1664, 0x160a},
305 {1792, 0x012e}, {1920, 0x010b}, {2048, 0x012f}, {2176, 0x2b0b},
306 {2304, 0x010c}, {2560, 0x010d}, {2816, 0x2b0d}, {3072, 0x010e},
307 {3328, 0x2b0e}, {3584, 0x0132}, {3840, 0x010f}, {4096, 0x0133},
308 {4608, 0x0110}, {5120, 0x0111}, {6144, 0x0112}, {7168, 0x0136},
309 {7680, 0x0113}, {8192, 0x0137}, {9216, 0x0114}, {10240, 0x0115},
310 {12288, 0x0116}, {14336, 0x013a}, {15360, 0x0117}, {16384, 0x013b},
311 {18432, 0x0118}, {20480, 0x0119}, {24576, 0x011a}, {28672, 0x013e},
312 {30720, 0x011b}, {32768, 0x013f}, {36864, 0x011c}, {40960, 0x011d},
313 {49152, 0x011e}, {61440, 0x011f}
316 static u32 __devinit mpc_i2c_get_sec_cfg_8xxx(void)
318 struct device_node *node = NULL;
322 node = of_find_node_by_name(NULL, "global-utilities");
324 const u32 *prop = of_get_property(node, "reg", NULL);
327 * Map and check POR Device Status Register 2
328 * (PORDEVSR2) at 0xE0014
330 reg = ioremap(get_immrbase() + *prop + 0x14, 0x4);
333 "Error: couldn't map PORDEVSR2\n");
335 val = in_be32(reg) & 0x00000080; /* sec-cfg */
345 static int __devinit mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock,
346 u32 prescaler, u32 *real_clk)
348 const struct mpc_i2c_divider *div = NULL;
352 if (clock == MPC_I2C_CLOCK_LEGACY) {
353 /* see below - default fdr = 0x1031 -> div = 16 * 3072 */
354 *real_clk = fsl_get_sys_freq() / prescaler / (16 * 3072);
358 /* Determine proper divider value */
359 if (of_device_is_compatible(node, "fsl,mpc8544-i2c"))
360 prescaler = mpc_i2c_get_sec_cfg_8xxx() ? 3 : 2;
364 divider = fsl_get_sys_freq() / clock / prescaler;
366 pr_debug("I2C: src_clock=%d clock=%d divider=%d\n",
367 fsl_get_sys_freq(), clock, divider);
370 * We want to choose an FDR/DFSR that generates an I2C bus speed that
371 * is equal to or lower than the requested speed.
373 for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_8xxx); i++) {
374 div = &mpc_i2c_dividers_8xxx[i];
375 if (div->divider >= divider)
379 *real_clk = fsl_get_sys_freq() / prescaler / div->divider;
380 return div ? (int)div->fdr : -EINVAL;
383 static void __devinit mpc_i2c_setup_8xxx(struct device_node *node,
385 u32 clock, u32 prescaler)
389 if (clock == MPC_I2C_CLOCK_PRESERVE) {
390 dev_dbg(i2c->dev, "using dfsrr %d, fdr %d\n",
391 readb(i2c->base + MPC_I2C_DFSRR),
392 readb(i2c->base + MPC_I2C_FDR));
396 ret = mpc_i2c_get_fdr_8xxx(node, clock, prescaler, &i2c->real_clk);
397 fdr = (ret >= 0) ? ret : 0x1031; /* backward compatibility */
399 writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
400 writeb((fdr >> 8) & 0xff, i2c->base + MPC_I2C_DFSRR);
403 dev_info(i2c->dev, "clock %d Hz (dfsrr=%d fdr=%d)\n",
404 i2c->real_clk, fdr >> 8, fdr & 0xff);
407 #else /* !CONFIG_FSL_SOC */
408 static void __devinit mpc_i2c_setup_8xxx(struct device_node *node,
410 u32 clock, u32 prescaler)
413 #endif /* CONFIG_FSL_SOC */
415 static void mpc_i2c_start(struct mpc_i2c *i2c)
417 /* Clear arbitration */
418 writeb(0, i2c->base + MPC_I2C_SR);
420 writeccr(i2c, CCR_MEN);
423 static void mpc_i2c_stop(struct mpc_i2c *i2c)
425 writeccr(i2c, CCR_MEN);
428 static int mpc_write(struct mpc_i2c *i2c, int target,
429 const u8 *data, int length, int restart)
432 unsigned timeout = i2c->adap.timeout;
433 u32 flags = restart ? CCR_RSTA : 0;
435 /* Start as master */
436 writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
437 /* Write target byte */
438 writeb((target << 1), i2c->base + MPC_I2C_DR);
440 result = i2c_wait(i2c, timeout, 1);
444 for (i = 0; i < length; i++) {
445 /* Write data byte */
446 writeb(data[i], i2c->base + MPC_I2C_DR);
448 result = i2c_wait(i2c, timeout, 1);
456 static int mpc_read(struct mpc_i2c *i2c, int target,
457 u8 *data, int length, int restart)
459 unsigned timeout = i2c->adap.timeout;
461 u32 flags = restart ? CCR_RSTA : 0;
463 /* Switch to read - restart */
464 writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
465 /* Write target address byte - this time with the read flag set */
466 writeb((target << 1) | 1, i2c->base + MPC_I2C_DR);
468 result = i2c_wait(i2c, timeout, 1);
474 writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
476 writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA);
478 readb(i2c->base + MPC_I2C_DR);
481 for (i = 0; i < length; i++) {
482 result = i2c_wait(i2c, timeout, 0);
486 /* Generate txack on next to last byte */
488 writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
489 /* Do not generate stop on last byte */
491 writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX);
492 data[i] = readb(i2c->base + MPC_I2C_DR);
498 static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
500 struct i2c_msg *pmsg;
503 unsigned long orig_jiffies = jiffies;
504 struct mpc_i2c *i2c = i2c_get_adapdata(adap);
508 /* Allow bus up to 1s to become not busy */
509 while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) {
510 if (signal_pending(current)) {
511 dev_dbg(i2c->dev, "Interrupted\n");
515 if (time_after(jiffies, orig_jiffies + HZ)) {
516 u8 status = readb(i2c->base + MPC_I2C_SR);
518 dev_dbg(i2c->dev, "timeout\n");
519 if ((status & (CSR_MCF | CSR_MBB | CSR_RXAK)) != 0) {
520 writeb(status & ~CSR_MAL,
521 i2c->base + MPC_I2C_SR);
529 for (i = 0; ret >= 0 && i < num; i++) {
532 "Doing %s %d bytes to 0x%02x - %d of %d messages\n",
533 pmsg->flags & I2C_M_RD ? "read" : "write",
534 pmsg->len, pmsg->addr, i + 1, num);
535 if (pmsg->flags & I2C_M_RD)
537 mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
540 mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
543 return (ret < 0) ? ret : num;
546 static u32 mpc_functionality(struct i2c_adapter *adap)
548 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
551 static const struct i2c_algorithm mpc_algo = {
552 .master_xfer = mpc_xfer,
553 .functionality = mpc_functionality,
556 static struct i2c_adapter mpc_ops = {
557 .owner = THIS_MODULE,
558 .name = "MPC adapter",
563 static int __devinit fsl_i2c_probe(struct platform_device *op,
564 const struct of_device_id *match)
568 u32 clock = MPC_I2C_CLOCK_LEGACY;
572 i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
576 i2c->dev = &op->dev; /* for debug and error output */
578 init_waitqueue_head(&i2c->queue);
580 i2c->base = of_iomap(op->dev.of_node, 0);
582 dev_err(i2c->dev, "failed to map controller\n");
587 i2c->irq = irq_of_parse_and_map(op->dev.of_node, 0);
588 if (i2c->irq) { /* no i2c->irq implies polling */
589 result = request_irq(i2c->irq, mpc_i2c_isr,
590 IRQF_SHARED, "i2c-mpc", i2c);
592 dev_err(i2c->dev, "failed to attach interrupt\n");
597 if (of_get_property(op->dev.of_node, "fsl,preserve-clocking", NULL)) {
598 clock = MPC_I2C_CLOCK_PRESERVE;
600 prop = of_get_property(op->dev.of_node, "clock-frequency",
602 if (prop && plen == sizeof(u32))
607 struct mpc_i2c_data *data = match->data;
608 data->setup(op->dev.of_node, i2c, clock, data->prescaler);
610 /* Backwards compatibility */
611 if (of_get_property(op->dev.of_node, "dfsrr", NULL))
612 mpc_i2c_setup_8xxx(op->dev.of_node, i2c, clock, 0);
615 prop = of_get_property(op->dev.of_node, "fsl,timeout", &plen);
616 if (prop && plen == sizeof(u32)) {
617 mpc_ops.timeout = *prop * HZ / 1000000;
618 if (mpc_ops.timeout < 5)
621 dev_info(i2c->dev, "timeout %u us\n", mpc_ops.timeout * 1000000 / HZ);
623 dev_set_drvdata(&op->dev, i2c);
626 i2c_set_adapdata(&i2c->adap, i2c);
627 i2c->adap.dev.parent = &op->dev;
628 i2c->adap.dev.of_node = of_node_get(op->dev.of_node);
630 result = i2c_add_adapter(&i2c->adap);
632 dev_err(i2c->dev, "failed to add adapter\n");
635 of_i2c_register_devices(&i2c->adap);
640 dev_set_drvdata(&op->dev, NULL);
641 free_irq(i2c->irq, i2c);
643 irq_dispose_mapping(i2c->irq);
650 static int __devexit fsl_i2c_remove(struct platform_device *op)
652 struct mpc_i2c *i2c = dev_get_drvdata(&op->dev);
654 i2c_del_adapter(&i2c->adap);
655 dev_set_drvdata(&op->dev, NULL);
658 free_irq(i2c->irq, i2c);
660 irq_dispose_mapping(i2c->irq);
666 static struct mpc_i2c_data mpc_i2c_data_512x __devinitdata = {
667 .setup = mpc_i2c_setup_512x,
670 static struct mpc_i2c_data mpc_i2c_data_52xx __devinitdata = {
671 .setup = mpc_i2c_setup_52xx,
674 static struct mpc_i2c_data mpc_i2c_data_8313 __devinitdata = {
675 .setup = mpc_i2c_setup_8xxx,
678 static struct mpc_i2c_data mpc_i2c_data_8543 __devinitdata = {
679 .setup = mpc_i2c_setup_8xxx,
683 static struct mpc_i2c_data mpc_i2c_data_8544 __devinitdata = {
684 .setup = mpc_i2c_setup_8xxx,
688 static const struct of_device_id mpc_i2c_of_match[] = {
689 {.compatible = "mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
690 {.compatible = "fsl,mpc5200b-i2c", .data = &mpc_i2c_data_52xx, },
691 {.compatible = "fsl,mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
692 {.compatible = "fsl,mpc5121-i2c", .data = &mpc_i2c_data_512x, },
693 {.compatible = "fsl,mpc8313-i2c", .data = &mpc_i2c_data_8313, },
694 {.compatible = "fsl,mpc8543-i2c", .data = &mpc_i2c_data_8543, },
695 {.compatible = "fsl,mpc8544-i2c", .data = &mpc_i2c_data_8544, },
696 /* Backward compatibility */
697 {.compatible = "fsl-i2c", },
700 MODULE_DEVICE_TABLE(of, mpc_i2c_of_match);
702 /* Structure for a device driver */
703 static struct of_platform_driver mpc_i2c_driver = {
704 .probe = fsl_i2c_probe,
705 .remove = __devexit_p(fsl_i2c_remove),
707 .owner = THIS_MODULE,
709 .of_match_table = mpc_i2c_of_match,
713 static int __init fsl_i2c_init(void)
717 rv = of_register_platform_driver(&mpc_i2c_driver);
719 printk(KERN_ERR DRV_NAME
720 " of_register_platform_driver failed (%i)\n", rv);
724 static void __exit fsl_i2c_exit(void)
726 of_unregister_platform_driver(&mpc_i2c_driver);
729 module_init(fsl_i2c_init);
730 module_exit(fsl_i2c_exit);
732 MODULE_AUTHOR("Adrian Cox <adrian@humboldt.co.uk>");
733 MODULE_DESCRIPTION("I2C-Bus adapter for MPC107 bridge and "
734 "MPC824x/83xx/85xx/86xx/512x/52xx processors");
735 MODULE_LICENSE("GPL");