xref: /openbmc/u-boot/drivers/i2c/sh_i2c.c (revision 8502f9f6)
1 /*
2  * Copyright (C) 2011, 2013 Renesas Solutions Corp.
3  * Copyright (C) 2011, 2013 Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  *
7  * NOTE: This driver should be converted to driver model before June 2017.
8  * Please see doc/driver-model/i2c-howto.txt for instructions.
9  */
10 
11 #include <common.h>
12 #include <i2c.h>
13 #include <asm/io.h>
14 
15 DECLARE_GLOBAL_DATA_PTR;
16 
17 /* Every register is 32bit aligned, but only 8bits in size */
18 #define ureg(name) u8 name; u8 __pad_##name##0; u16 __pad_##name##1;
19 struct sh_i2c {
20 	ureg(icdr);
21 	ureg(iccr);
22 	ureg(icsr);
23 	ureg(icic);
24 	ureg(iccl);
25 	ureg(icch);
26 };
27 #undef ureg
28 
29 /* ICCR */
30 #define SH_I2C_ICCR_ICE		(1 << 7)
31 #define SH_I2C_ICCR_RACK	(1 << 6)
32 #define SH_I2C_ICCR_RTS		(1 << 4)
33 #define SH_I2C_ICCR_BUSY	(1 << 2)
34 #define SH_I2C_ICCR_SCP		(1 << 0)
35 
36 /* ICSR / ICIC */
37 #define SH_IC_BUSY	(1 << 4)
38 #define SH_IC_TACK	(1 << 2)
39 #define SH_IC_WAIT	(1 << 1)
40 #define SH_IC_DTE	(1 << 0)
41 
42 #ifdef CONFIG_SH_I2C_8BIT
43 /* store 8th bit of iccl and icch in ICIC register */
44 #define SH_I2C_ICIC_ICCLB8	(1 << 7)
45 #define SH_I2C_ICIC_ICCHB8	(1 << 6)
46 #endif
47 
48 static const struct sh_i2c *i2c_dev[CONFIG_SYS_I2C_SH_NUM_CONTROLLERS] = {
49 	(struct sh_i2c *)CONFIG_SYS_I2C_SH_BASE0,
50 #ifdef CONFIG_SYS_I2C_SH_BASE1
51 	(struct sh_i2c *)CONFIG_SYS_I2C_SH_BASE1,
52 #endif
53 #ifdef CONFIG_SYS_I2C_SH_BASE2
54 	(struct sh_i2c *)CONFIG_SYS_I2C_SH_BASE2,
55 #endif
56 #ifdef CONFIG_SYS_I2C_SH_BASE3
57 	(struct sh_i2c *)CONFIG_SYS_I2C_SH_BASE3,
58 #endif
59 #ifdef CONFIG_SYS_I2C_SH_BASE4
60 	(struct sh_i2c *)CONFIG_SYS_I2C_SH_BASE4,
61 #endif
62 };
63 
64 static u16 iccl, icch;
65 
66 #define IRQ_WAIT 1000
67 
68 static void sh_irq_dte(struct sh_i2c *dev)
69 {
70 	int i;
71 
72 	for (i = 0; i < IRQ_WAIT; i++) {
73 		if (SH_IC_DTE & readb(&dev->icsr))
74 			break;
75 		udelay(10);
76 	}
77 }
78 
79 static int sh_irq_dte_with_tack(struct sh_i2c *dev)
80 {
81 	int i;
82 
83 	for (i = 0; i < IRQ_WAIT; i++) {
84 		if (SH_IC_DTE & readb(&dev->icsr))
85 			break;
86 		if (SH_IC_TACK & readb(&dev->icsr))
87 			return -1;
88 		udelay(10);
89 	}
90 	return 0;
91 }
92 
93 static void sh_irq_busy(struct sh_i2c *dev)
94 {
95 	int i;
96 
97 	for (i = 0; i < IRQ_WAIT; i++) {
98 		if (!(SH_IC_BUSY & readb(&dev->icsr)))
99 			break;
100 		udelay(10);
101 	}
102 }
103 
104 static int sh_i2c_set_addr(struct sh_i2c *dev, u8 chip, u8 addr, int stop)
105 {
106 	u8 icic = SH_IC_TACK;
107 
108 	debug("%s: chip: %x, addr: %x iccl: %x, icch %x\n",
109 				__func__, chip, addr, iccl, icch);
110 	clrbits_8(&dev->iccr, SH_I2C_ICCR_ICE);
111 	setbits_8(&dev->iccr, SH_I2C_ICCR_ICE);
112 
113 	writeb(iccl & 0xff, &dev->iccl);
114 	writeb(icch & 0xff, &dev->icch);
115 #ifdef CONFIG_SH_I2C_8BIT
116 	if (iccl > 0xff)
117 		icic |= SH_I2C_ICIC_ICCLB8;
118 	if (icch > 0xff)
119 		icic |= SH_I2C_ICIC_ICCHB8;
120 #endif
121 	writeb(icic, &dev->icic);
122 
123 	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RTS|SH_I2C_ICCR_BUSY), &dev->iccr);
124 	sh_irq_dte(dev);
125 
126 	clrbits_8(&dev->icsr, SH_IC_TACK);
127 	writeb(chip << 1, &dev->icdr);
128 	if (sh_irq_dte_with_tack(dev) != 0)
129 		return -1;
130 
131 	writeb(addr, &dev->icdr);
132 	if (stop)
133 		writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RTS), &dev->iccr);
134 
135 	if (sh_irq_dte_with_tack(dev) != 0)
136 		return -1;
137 	return 0;
138 }
139 
140 static void sh_i2c_finish(struct sh_i2c *dev)
141 {
142 	writeb(0, &dev->icsr);
143 	clrbits_8(&dev->iccr, SH_I2C_ICCR_ICE);
144 }
145 
146 static int
147 sh_i2c_raw_write(struct sh_i2c *dev, u8 chip, uint addr, u8 val)
148 {
149 	int ret = -1;
150 	if (sh_i2c_set_addr(dev, chip, addr, 0) != 0)
151 		goto exit0;
152 	udelay(10);
153 
154 	writeb(val, &dev->icdr);
155 	if (sh_irq_dte_with_tack(dev) != 0)
156 		goto exit0;
157 
158 	writeb((SH_I2C_ICCR_ICE | SH_I2C_ICCR_RTS), &dev->iccr);
159 	if (sh_irq_dte_with_tack(dev) != 0)
160 		goto exit0;
161 	sh_irq_busy(dev);
162 	ret = 0;
163 
164 exit0:
165 	sh_i2c_finish(dev);
166 	return ret;
167 }
168 
169 static int sh_i2c_raw_read(struct sh_i2c *dev, u8 chip, u8 addr)
170 {
171 	int ret = -1;
172 
173 #if defined(CONFIG_SH73A0)
174 	if (sh_i2c_set_addr(dev, chip, addr, 0) != 0)
175 		goto exit0;
176 #else
177 	if (sh_i2c_set_addr(dev, chip, addr, 1) != 0)
178 		goto exit0;
179 	udelay(100);
180 #endif
181 
182 	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RTS|SH_I2C_ICCR_BUSY), &dev->iccr);
183 	sh_irq_dte(dev);
184 
185 	writeb(chip << 1 | 0x01, &dev->icdr);
186 	if (sh_irq_dte_with_tack(dev) != 0)
187 		goto exit0;
188 
189 	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_SCP), &dev->iccr);
190 	if (sh_irq_dte_with_tack(dev) != 0)
191 		goto exit0;
192 
193 	ret = readb(&dev->icdr) & 0xff;
194 
195 	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RACK), &dev->iccr);
196 	readb(&dev->icdr); /* Dummy read */
197 	sh_irq_busy(dev);
198 
199 exit0:
200 	sh_i2c_finish(dev);
201 
202 	return ret;
203 }
204 
205 static void
206 sh_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd)
207 {
208 	int num, denom, tmp;
209 
210 	/* No i2c support prior to relocation */
211 	if (!(gd->flags & GD_FLG_RELOC))
212 		return;
213 
214 	/*
215 	 * Calculate the value for iccl. From the data sheet:
216 	 * iccl = (p-clock / transfer-rate) * (L / (L + H))
217 	 * where L and H are the SCL low and high ratio.
218 	 */
219 	num = CONFIG_SH_I2C_CLOCK * CONFIG_SH_I2C_DATA_LOW;
220 	denom = speed * (CONFIG_SH_I2C_DATA_HIGH + CONFIG_SH_I2C_DATA_LOW);
221 	tmp = num * 10 / denom;
222 	if (tmp % 10 >= 5)
223 		iccl = (u16)((num/denom) + 1);
224 	else
225 		iccl = (u16)(num/denom);
226 
227 	/* Calculate the value for icch. From the data sheet:
228 	   icch = (p clock / transfer rate) * (H / (L + H)) */
229 	num = CONFIG_SH_I2C_CLOCK * CONFIG_SH_I2C_DATA_HIGH;
230 	tmp = num * 10 / denom;
231 	if (tmp % 10 >= 5)
232 		icch = (u16)((num/denom) + 1);
233 	else
234 		icch = (u16)(num/denom);
235 
236 	debug("clock: %d, speed %d, iccl: %x, icch: %x\n",
237 			CONFIG_SH_I2C_CLOCK, speed, iccl, icch);
238 }
239 
240 static int sh_i2c_read(struct i2c_adapter *adap, uint8_t chip,
241 				uint addr, int alen, u8 *data, int len)
242 {
243 	int ret, i;
244 	struct sh_i2c *dev = (struct sh_i2c *)i2c_dev[adap->hwadapnr];
245 
246 	for (i = 0; i < len; i++) {
247 		ret = sh_i2c_raw_read(dev, chip, addr + i);
248 		if (ret < 0)
249 			return -1;
250 
251 		data[i] = ret & 0xff;
252 		debug("%s: data[%d]: %02x\n", __func__, i, data[i]);
253 	}
254 
255 	return 0;
256 }
257 
258 static int sh_i2c_write(struct i2c_adapter *adap, uint8_t chip, uint addr,
259 				int alen, u8 *data, int len)
260 {
261 	struct sh_i2c *dev = (struct sh_i2c *)i2c_dev[adap->hwadapnr];
262 	int i;
263 
264 	for (i = 0; i < len; i++) {
265 		debug("%s: data[%d]: %02x\n", __func__, i, data[i]);
266 		if (sh_i2c_raw_write(dev, chip, addr + i, data[i]) != 0)
267 			return -1;
268 	}
269 	return 0;
270 }
271 
272 static int
273 sh_i2c_probe(struct i2c_adapter *adap, u8 dev)
274 {
275 	u8 dummy[1];
276 
277 	return sh_i2c_read(adap, dev, 0, 0, dummy, sizeof dummy);
278 }
279 
280 static unsigned int sh_i2c_set_bus_speed(struct i2c_adapter *adap,
281 			unsigned int speed)
282 {
283 	struct sh_i2c *dev = (struct sh_i2c *)i2c_dev[adap->hwadapnr];
284 
285 	sh_i2c_finish(dev);
286 	sh_i2c_init(adap, speed, 0);
287 
288 	return 0;
289 }
290 
291 /*
292  * Register RCAR i2c adapters
293  */
294 U_BOOT_I2C_ADAP_COMPLETE(sh_0, sh_i2c_init, sh_i2c_probe, sh_i2c_read,
295 	sh_i2c_write, sh_i2c_set_bus_speed, CONFIG_SYS_I2C_SH_SPEED0, 0, 0)
296 #ifdef CONFIG_SYS_I2C_SH_BASE1
297 U_BOOT_I2C_ADAP_COMPLETE(sh_1, sh_i2c_init, sh_i2c_probe, sh_i2c_read,
298 	sh_i2c_write, sh_i2c_set_bus_speed, CONFIG_SYS_I2C_SH_SPEED1, 0, 1)
299 #endif
300 #ifdef CONFIG_SYS_I2C_SH_BASE2
301 U_BOOT_I2C_ADAP_COMPLETE(sh_2, sh_i2c_init, sh_i2c_probe, sh_i2c_read,
302 	sh_i2c_write, sh_i2c_set_bus_speed, CONFIG_SYS_I2C_SH_SPEED2, 0, 2)
303 #endif
304 #ifdef CONFIG_SYS_I2C_SH_BASE3
305 U_BOOT_I2C_ADAP_COMPLETE(sh_3, sh_i2c_init, sh_i2c_probe, sh_i2c_read,
306 	sh_i2c_write, sh_i2c_set_bus_speed, CONFIG_SYS_I2C_SH_SPEED3, 0, 3)
307 #endif
308 #ifdef CONFIG_SYS_I2C_SH_BASE4
309 U_BOOT_I2C_ADAP_COMPLETE(sh_4, sh_i2c_init, sh_i2c_probe, sh_i2c_read,
310 	sh_i2c_write, sh_i2c_set_bus_speed, CONFIG_SYS_I2C_SH_SPEED4, 0, 4)
311 #endif
312