xref: /openbmc/u-boot/drivers/i2c/sh_i2c.c (revision 6a99f03d)
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 
8 #include <common.h>
9 #include <i2c.h>
10 #include <asm/io.h>
11 
12 DECLARE_GLOBAL_DATA_PTR;
13 
14 /* Every register is 32bit aligned, but only 8bits in size */
15 #define ureg(name) u8 name; u8 __pad_##name##0; u16 __pad_##name##1;
16 struct sh_i2c {
17 	ureg(icdr);
18 	ureg(iccr);
19 	ureg(icsr);
20 	ureg(icic);
21 	ureg(iccl);
22 	ureg(icch);
23 };
24 #undef ureg
25 
26 /* ICCR */
27 #define SH_I2C_ICCR_ICE		(1 << 7)
28 #define SH_I2C_ICCR_RACK	(1 << 6)
29 #define SH_I2C_ICCR_RTS		(1 << 4)
30 #define SH_I2C_ICCR_BUSY	(1 << 2)
31 #define SH_I2C_ICCR_SCP		(1 << 0)
32 
33 /* ICSR / ICIC */
34 #define SH_IC_BUSY	(1 << 4)
35 #define SH_IC_TACK	(1 << 2)
36 #define SH_IC_WAIT	(1 << 1)
37 #define SH_IC_DTE	(1 << 0)
38 
39 #ifdef CONFIG_SH_I2C_8BIT
40 /* store 8th bit of iccl and icch in ICIC register */
41 #define SH_I2C_ICIC_ICCLB8	(1 << 7)
42 #define SH_I2C_ICIC_ICCHB8	(1 << 6)
43 #endif
44 
45 static const struct sh_i2c *i2c_dev[CONFIG_SYS_I2C_SH_NUM_CONTROLLERS] = {
46 	(struct sh_i2c *)CONFIG_SYS_I2C_SH_BASE0,
47 #ifdef CONFIG_SYS_I2C_SH_BASE1
48 	(struct sh_i2c *)CONFIG_SYS_I2C_SH_BASE1,
49 #endif
50 #ifdef CONFIG_SYS_I2C_SH_BASE2
51 	(struct sh_i2c *)CONFIG_SYS_I2C_SH_BASE2,
52 #endif
53 #ifdef CONFIG_SYS_I2C_SH_BASE3
54 	(struct sh_i2c *)CONFIG_SYS_I2C_SH_BASE3,
55 #endif
56 #ifdef CONFIG_SYS_I2C_SH_BASE4
57 	(struct sh_i2c *)CONFIG_SYS_I2C_SH_BASE4,
58 #endif
59 };
60 
61 static u16 iccl, icch;
62 
63 #define IRQ_WAIT 1000
64 
65 static void sh_irq_dte(struct sh_i2c *dev)
66 {
67 	int i;
68 
69 	for (i = 0; i < IRQ_WAIT; i++) {
70 		if (SH_IC_DTE & readb(&dev->icsr))
71 			break;
72 		udelay(10);
73 	}
74 }
75 
76 static int sh_irq_dte_with_tack(struct sh_i2c *dev)
77 {
78 	int i;
79 
80 	for (i = 0; i < IRQ_WAIT; i++) {
81 		if (SH_IC_DTE & readb(&dev->icsr))
82 			break;
83 		if (SH_IC_TACK & readb(&dev->icsr))
84 			return -1;
85 		udelay(10);
86 	}
87 	return 0;
88 }
89 
90 static void sh_irq_busy(struct sh_i2c *dev)
91 {
92 	int i;
93 
94 	for (i = 0; i < IRQ_WAIT; i++) {
95 		if (!(SH_IC_BUSY & readb(&dev->icsr)))
96 			break;
97 		udelay(10);
98 	}
99 }
100 
101 static int sh_i2c_set_addr(struct sh_i2c *dev, u8 chip, u8 addr, int stop)
102 {
103 	u8 icic = SH_IC_TACK;
104 
105 	debug("%s: chip: %x, addr: %x iccl: %x, icch %x\n",
106 				__func__, chip, addr, iccl, icch);
107 	clrbits_8(&dev->iccr, SH_I2C_ICCR_ICE);
108 	setbits_8(&dev->iccr, SH_I2C_ICCR_ICE);
109 
110 	writeb(iccl & 0xff, &dev->iccl);
111 	writeb(icch & 0xff, &dev->icch);
112 #ifdef CONFIG_SH_I2C_8BIT
113 	if (iccl > 0xff)
114 		icic |= SH_I2C_ICIC_ICCLB8;
115 	if (icch > 0xff)
116 		icic |= SH_I2C_ICIC_ICCHB8;
117 #endif
118 	writeb(icic, &dev->icic);
119 
120 	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RTS|SH_I2C_ICCR_BUSY), &dev->iccr);
121 	sh_irq_dte(dev);
122 
123 	clrbits_8(&dev->icsr, SH_IC_TACK);
124 	writeb(chip << 1, &dev->icdr);
125 	if (sh_irq_dte_with_tack(dev) != 0)
126 		return -1;
127 
128 	writeb(addr, &dev->icdr);
129 	if (stop)
130 		writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RTS), &dev->iccr);
131 
132 	if (sh_irq_dte_with_tack(dev) != 0)
133 		return -1;
134 	return 0;
135 }
136 
137 static void sh_i2c_finish(struct sh_i2c *dev)
138 {
139 	writeb(0, &dev->icsr);
140 	clrbits_8(&dev->iccr, SH_I2C_ICCR_ICE);
141 }
142 
143 static int
144 sh_i2c_raw_write(struct sh_i2c *dev, u8 chip, uint addr, u8 val)
145 {
146 	int ret = -1;
147 	if (sh_i2c_set_addr(dev, chip, addr, 0) != 0)
148 		goto exit0;
149 	udelay(10);
150 
151 	writeb(val, &dev->icdr);
152 	if (sh_irq_dte_with_tack(dev) != 0)
153 		goto exit0;
154 
155 	writeb((SH_I2C_ICCR_ICE | SH_I2C_ICCR_RTS), &dev->iccr);
156 	if (sh_irq_dte_with_tack(dev) != 0)
157 		goto exit0;
158 	sh_irq_busy(dev);
159 	ret = 0;
160 
161 exit0:
162 	sh_i2c_finish(dev);
163 	return ret;
164 }
165 
166 static int sh_i2c_raw_read(struct sh_i2c *dev, u8 chip, u8 addr)
167 {
168 	int ret = -1;
169 
170 #if defined(CONFIG_SH73A0)
171 	if (sh_i2c_set_addr(dev, chip, addr, 0) != 0)
172 		goto exit0;
173 #else
174 	if (sh_i2c_set_addr(dev, chip, addr, 1) != 0)
175 		goto exit0;
176 	udelay(100);
177 #endif
178 
179 	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RTS|SH_I2C_ICCR_BUSY), &dev->iccr);
180 	sh_irq_dte(dev);
181 
182 	writeb(chip << 1 | 0x01, &dev->icdr);
183 	if (sh_irq_dte_with_tack(dev) != 0)
184 		goto exit0;
185 
186 	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_SCP), &dev->iccr);
187 	if (sh_irq_dte_with_tack(dev) != 0)
188 		goto exit0;
189 
190 	ret = readb(&dev->icdr) & 0xff;
191 
192 	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RACK), &dev->iccr);
193 	readb(&dev->icdr); /* Dummy read */
194 	sh_irq_busy(dev);
195 
196 exit0:
197 	sh_i2c_finish(dev);
198 
199 	return ret;
200 }
201 
202 static void
203 sh_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd)
204 {
205 	int num, denom, tmp;
206 
207 	/* No i2c support prior to relocation */
208 	if (!(gd->flags & GD_FLG_RELOC))
209 		return;
210 
211 	/*
212 	 * Calculate the value for iccl. From the data sheet:
213 	 * iccl = (p-clock / transfer-rate) * (L / (L + H))
214 	 * where L and H are the SCL low and high ratio.
215 	 */
216 	num = CONFIG_SH_I2C_CLOCK * CONFIG_SH_I2C_DATA_LOW;
217 	denom = speed * (CONFIG_SH_I2C_DATA_HIGH + CONFIG_SH_I2C_DATA_LOW);
218 	tmp = num * 10 / denom;
219 	if (tmp % 10 >= 5)
220 		iccl = (u16)((num/denom) + 1);
221 	else
222 		iccl = (u16)(num/denom);
223 
224 	/* Calculate the value for icch. From the data sheet:
225 	   icch = (p clock / transfer rate) * (H / (L + H)) */
226 	num = CONFIG_SH_I2C_CLOCK * CONFIG_SH_I2C_DATA_HIGH;
227 	tmp = num * 10 / denom;
228 	if (tmp % 10 >= 5)
229 		icch = (u16)((num/denom) + 1);
230 	else
231 		icch = (u16)(num/denom);
232 
233 	debug("clock: %d, speed %d, iccl: %x, icch: %x\n",
234 			CONFIG_SH_I2C_CLOCK, speed, iccl, icch);
235 }
236 
237 static int sh_i2c_read(struct i2c_adapter *adap, uint8_t chip,
238 				uint addr, int alen, u8 *data, int len)
239 {
240 	int ret, i;
241 	struct sh_i2c *dev = (struct sh_i2c *)i2c_dev[adap->hwadapnr];
242 
243 	for (i = 0; i < len; i++) {
244 		ret = sh_i2c_raw_read(dev, chip, addr + i);
245 		if (ret < 0)
246 			return -1;
247 
248 		data[i] = ret & 0xff;
249 		debug("%s: data[%d]: %02x\n", __func__, i, data[i]);
250 	}
251 
252 	return 0;
253 }
254 
255 static int sh_i2c_write(struct i2c_adapter *adap, uint8_t chip, uint addr,
256 				int alen, u8 *data, int len)
257 {
258 	struct sh_i2c *dev = (struct sh_i2c *)i2c_dev[adap->hwadapnr];
259 	int i;
260 
261 	for (i = 0; i < len; i++) {
262 		debug("%s: data[%d]: %02x\n", __func__, i, data[i]);
263 		if (sh_i2c_raw_write(dev, chip, addr + i, data[i]) != 0)
264 			return -1;
265 	}
266 	return 0;
267 }
268 
269 static int
270 sh_i2c_probe(struct i2c_adapter *adap, u8 dev)
271 {
272 	return sh_i2c_read(adap, dev, 0, 0, NULL, 0);
273 }
274 
275 static unsigned int sh_i2c_set_bus_speed(struct i2c_adapter *adap,
276 			unsigned int speed)
277 {
278 	struct sh_i2c *dev = (struct sh_i2c *)i2c_dev[adap->hwadapnr];
279 
280 	sh_i2c_finish(dev);
281 	sh_i2c_init(adap, speed, 0);
282 
283 	return 0;
284 }
285 
286 /*
287  * Register RCAR i2c adapters
288  */
289 U_BOOT_I2C_ADAP_COMPLETE(sh_0, sh_i2c_init, sh_i2c_probe, sh_i2c_read,
290 	sh_i2c_write, sh_i2c_set_bus_speed, CONFIG_SYS_I2C_SH_SPEED0, 0, 0)
291 #ifdef CONFIG_SYS_I2C_SH_BASE1
292 U_BOOT_I2C_ADAP_COMPLETE(sh_1, sh_i2c_init, sh_i2c_probe, sh_i2c_read,
293 	sh_i2c_write, sh_i2c_set_bus_speed, CONFIG_SYS_I2C_SH_SPEED1, 0, 1)
294 #endif
295 #ifdef CONFIG_SYS_I2C_SH_BASE2
296 U_BOOT_I2C_ADAP_COMPLETE(sh_2, sh_i2c_init, sh_i2c_probe, sh_i2c_read,
297 	sh_i2c_write, sh_i2c_set_bus_speed, CONFIG_SYS_I2C_SH_SPEED2, 0, 2)
298 #endif
299 #ifdef CONFIG_SYS_I2C_SH_BASE3
300 U_BOOT_I2C_ADAP_COMPLETE(sh_3, sh_i2c_init, sh_i2c_probe, sh_i2c_read,
301 	sh_i2c_write, sh_i2c_set_bus_speed, CONFIG_SYS_I2C_SH_SPEED3, 0, 3)
302 #endif
303 #ifdef CONFIG_SYS_I2C_SH_BASE4
304 U_BOOT_I2C_ADAP_COMPLETE(sh_4, sh_i2c_init, sh_i2c_probe, sh_i2c_read,
305 	sh_i2c_write, sh_i2c_set_bus_speed, CONFIG_SYS_I2C_SH_SPEED4, 0, 4)
306 #endif
307