xref: /openbmc/u-boot/drivers/i2c/ihs_i2c.c (revision 544acb07)
1 /*
2  * (C) Copyright 2013
3  * Dirk Eibach,  Guntermann & Drunck GmbH, eibach@gdsys.de
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <i2c.h>
10 #include <gdsys_fpga.h>
11 
12 DECLARE_GLOBAL_DATA_PTR;
13 
14 #ifdef CONFIG_SYS_I2C_IHS_DUAL
15 #define I2C_SET_REG(fld, val) \
16 	do { \
17 		if (I2C_ADAP_HWNR & 0x10) \
18 			FPGA_SET_REG(I2C_ADAP_HWNR & 0xf, i2c1.fld, val); \
19 		else \
20 			FPGA_SET_REG(I2C_ADAP_HWNR, i2c0.fld, val); \
21 	} while (0)
22 #else
23 #define I2C_SET_REG(fld, val) \
24 		FPGA_SET_REG(I2C_ADAP_HWNR, i2c0.fld, val)
25 #endif
26 
27 #ifdef CONFIG_SYS_I2C_IHS_DUAL
28 #define I2C_GET_REG(fld, val) \
29 	do {					\
30 		if (I2C_ADAP_HWNR & 0x10) \
31 			FPGA_GET_REG(I2C_ADAP_HWNR & 0xf, i2c1.fld, val); \
32 		else \
33 			FPGA_GET_REG(I2C_ADAP_HWNR, i2c0.fld, val); \
34 	} while (0)
35 #else
36 #define I2C_GET_REG(fld, val) \
37 		FPGA_GET_REG(I2C_ADAP_HWNR, i2c0.fld, val)
38 #endif
39 
40 enum {
41 	I2CINT_ERROR_EV = 1 << 13,
42 	I2CINT_TRANSMIT_EV = 1 << 14,
43 	I2CINT_RECEIVE_EV = 1 << 15,
44 };
45 
46 enum {
47 	I2CMB_WRITE = 1 << 10,
48 	I2CMB_2BYTE = 1 << 11,
49 	I2CMB_HOLD_BUS = 1 << 13,
50 	I2CMB_NATIVE = 2 << 14,
51 };
52 
53 static int wait_for_int(bool read)
54 {
55 	u16 val;
56 	unsigned int ctr = 0;
57 
58 	I2C_GET_REG(interrupt_status, &val);
59 	while (!(val & (I2CINT_ERROR_EV
60 	       | (read ? I2CINT_RECEIVE_EV : I2CINT_TRANSMIT_EV)))) {
61 		udelay(10);
62 		if (ctr++ > 5000) {
63 			return 1;
64 		}
65 		I2C_GET_REG(interrupt_status, &val);
66 	}
67 
68 	return (val & I2CINT_ERROR_EV) ? 1 : 0;
69 }
70 
71 static int ihs_i2c_transfer(uchar chip, uchar *buffer, int len, bool read,
72 			    bool is_last)
73 {
74 	u16 val;
75 
76 	I2C_SET_REG(interrupt_status, I2CINT_ERROR_EV
77 		     | I2CINT_RECEIVE_EV | I2CINT_TRANSMIT_EV);
78 	I2C_GET_REG(interrupt_status, &val);
79 
80 	if (!read && len) {
81 		val = buffer[0];
82 
83 		if (len > 1)
84 			val |= buffer[1] << 8;
85 		I2C_SET_REG(write_mailbox_ext, val);
86 	}
87 
88 	I2C_SET_REG(write_mailbox,
89 		    I2CMB_NATIVE
90 		    | (read ? 0 : I2CMB_WRITE)
91 		    | (chip << 1)
92 		    | ((len > 1) ? I2CMB_2BYTE : 0)
93 		    | (is_last ? 0 : I2CMB_HOLD_BUS));
94 
95 	if (wait_for_int(read))
96 		return 1;
97 
98 	if (read) {
99 		I2C_GET_REG(read_mailbox_ext, &val);
100 		buffer[0] = val & 0xff;
101 		if (len > 1)
102 			buffer[1] = val >> 8;
103 	}
104 
105 	return 0;
106 }
107 
108 static int ihs_i2c_address(uchar chip, uint addr, int alen, bool hold_bus)
109 {
110 	int shift = (alen-1) * 8;
111 
112 	while (alen) {
113 		int transfer = min(alen, 2);
114 		uchar buf[2];
115 		bool is_last = alen <= transfer;
116 
117 		buf[0] = addr >> shift;
118 		if (alen > 1)
119 			buf[1] = addr >> (shift - 8);
120 
121 		if (ihs_i2c_transfer(chip, buf, transfer, false,
122 				     hold_bus ? false : is_last))
123 			return 1;
124 
125 		shift -= 16;
126 		alen -= transfer;
127 	}
128 
129 	return 0;
130 }
131 
132 static int ihs_i2c_access(struct i2c_adapter *adap, uchar chip, uint addr,
133 			  int alen, uchar *buffer, int len, bool read)
134 {
135 	if (len <= 0)
136 		return 1;
137 
138 	if (ihs_i2c_address(chip, addr, alen, len))
139 		return 1;
140 
141 	while (len) {
142 		int transfer = min(len, 2);
143 
144 		if (ihs_i2c_transfer(chip, buffer, transfer, read,
145 				     len <= transfer))
146 			return 1;
147 
148 		buffer += transfer;
149 		addr += transfer;
150 		len -= transfer;
151 	}
152 
153 	return 0;
154 }
155 
156 
157 static void ihs_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
158 {
159 #ifdef CONFIG_SYS_I2C_INIT_BOARD
160 	/*
161 	 * Call board specific i2c bus reset routine before accessing the
162 	 * environment, which might be in a chip on that bus. For details
163 	 * about this problem see doc/I2C_Edge_Conditions.
164 	 */
165 	i2c_init_board();
166 #endif
167 }
168 
169 static int ihs_i2c_probe(struct i2c_adapter *adap, uchar chip)
170 {
171 	uchar buffer[2];
172 
173 	if (ihs_i2c_transfer(chip, buffer, 0, true, true))
174 		return 1;
175 
176 	return 0;
177 }
178 
179 static int ihs_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
180 			int alen, uchar *buffer, int len)
181 {
182 	return ihs_i2c_access(adap, chip, addr, alen, buffer, len, true);
183 }
184 
185 static int ihs_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
186 			 int alen, uchar *buffer, int len)
187 {
188 	return ihs_i2c_access(adap, chip, addr, alen, buffer, len, false);
189 }
190 
191 static unsigned int ihs_i2c_set_bus_speed(struct i2c_adapter *adap,
192 					  unsigned int speed)
193 {
194 	if (speed != adap->speed)
195 		return 1;
196 	return speed;
197 }
198 
199 /*
200  * Register IHS i2c adapters
201  */
202 #ifdef CONFIG_SYS_I2C_IHS_CH0
203 U_BOOT_I2C_ADAP_COMPLETE(ihs0, ihs_i2c_init, ihs_i2c_probe,
204 			 ihs_i2c_read, ihs_i2c_write,
205 			 ihs_i2c_set_bus_speed,
206 			 CONFIG_SYS_I2C_IHS_SPEED_0,
207 			 CONFIG_SYS_I2C_IHS_SLAVE_0, 0)
208 #ifdef CONFIG_SYS_I2C_IHS_DUAL
209 U_BOOT_I2C_ADAP_COMPLETE(ihs0_1, ihs_i2c_init, ihs_i2c_probe,
210 			 ihs_i2c_read, ihs_i2c_write,
211 			 ihs_i2c_set_bus_speed,
212 			 CONFIG_SYS_I2C_IHS_SPEED_0_1,
213 			 CONFIG_SYS_I2C_IHS_SLAVE_0_1, 16)
214 #endif
215 #endif
216 #ifdef CONFIG_SYS_I2C_IHS_CH1
217 U_BOOT_I2C_ADAP_COMPLETE(ihs1, ihs_i2c_init, ihs_i2c_probe,
218 			 ihs_i2c_read, ihs_i2c_write,
219 			 ihs_i2c_set_bus_speed,
220 			 CONFIG_SYS_I2C_IHS_SPEED_1,
221 			 CONFIG_SYS_I2C_IHS_SLAVE_1, 1)
222 #ifdef CONFIG_SYS_I2C_IHS_DUAL
223 U_BOOT_I2C_ADAP_COMPLETE(ihs1_1, ihs_i2c_init, ihs_i2c_probe,
224 			 ihs_i2c_read, ihs_i2c_write,
225 			 ihs_i2c_set_bus_speed,
226 			 CONFIG_SYS_I2C_IHS_SPEED_1_1,
227 			 CONFIG_SYS_I2C_IHS_SLAVE_1_1, 17)
228 #endif
229 #endif
230 #ifdef CONFIG_SYS_I2C_IHS_CH2
231 U_BOOT_I2C_ADAP_COMPLETE(ihs2, ihs_i2c_init, ihs_i2c_probe,
232 			 ihs_i2c_read, ihs_i2c_write,
233 			 ihs_i2c_set_bus_speed,
234 			 CONFIG_SYS_I2C_IHS_SPEED_2,
235 			 CONFIG_SYS_I2C_IHS_SLAVE_2, 2)
236 #ifdef CONFIG_SYS_I2C_IHS_DUAL
237 U_BOOT_I2C_ADAP_COMPLETE(ihs2_1, ihs_i2c_init, ihs_i2c_probe,
238 			 ihs_i2c_read, ihs_i2c_write,
239 			 ihs_i2c_set_bus_speed,
240 			 CONFIG_SYS_I2C_IHS_SPEED_2_1,
241 			 CONFIG_SYS_I2C_IHS_SLAVE_2_1, 18)
242 #endif
243 #endif
244 #ifdef CONFIG_SYS_I2C_IHS_CH3
245 U_BOOT_I2C_ADAP_COMPLETE(ihs3, ihs_i2c_init, ihs_i2c_probe,
246 			 ihs_i2c_read, ihs_i2c_write,
247 			 ihs_i2c_set_bus_speed,
248 			 CONFIG_SYS_I2C_IHS_SPEED_3,
249 			 CONFIG_SYS_I2C_IHS_SLAVE_3, 3)
250 #ifdef CONFIG_SYS_I2C_IHS_DUAL
251 U_BOOT_I2C_ADAP_COMPLETE(ihs3_1, ihs_i2c_init, ihs_i2c_probe,
252 			 ihs_i2c_read, ihs_i2c_write,
253 			 ihs_i2c_set_bus_speed,
254 			 CONFIG_SYS_I2C_IHS_SPEED_3_1,
255 			 CONFIG_SYS_I2C_IHS_SLAVE_3_1, 19)
256 #endif
257 #endif
258