blob: fe66ce2a4ac510c53e469bbcb8e42686108d5027 [file] [log] [blame]
Dirk Eibachb46226b2014-07-03 09:28:18 +02001/*
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
12DECLARE_GLOBAL_DATA_PTR;
13
14enum {
15 I2CINT_ERROR_EV = 1 << 13,
16 I2CINT_TRANSMIT_EV = 1 << 14,
17 I2CINT_RECEIVE_EV = 1 << 15,
18};
19
20enum {
21 I2CMB_WRITE = 1 << 10,
22 I2CMB_2BYTE = 1 << 11,
23 I2CMB_HOLD_BUS = 1 << 13,
24 I2CMB_NATIVE = 2 << 14,
25};
26
27static int wait_for_int(bool read)
28{
29 u16 val;
30 unsigned int ctr = 0;
31
32 FPGA_GET_REG(I2C_ADAP_HWNR, i2c.interrupt_status, &val);
33 while (!(val & (I2CINT_ERROR_EV
34 | (read ? I2CINT_RECEIVE_EV : I2CINT_TRANSMIT_EV)))) {
35 udelay(10);
36 if (ctr++ > 5000) {
Dirk Eibachb46226b2014-07-03 09:28:18 +020037 return 1;
38 }
39 FPGA_GET_REG(I2C_ADAP_HWNR, i2c.interrupt_status, &val);
40 }
41
42 return (val & I2CINT_ERROR_EV) ? 1 : 0;
43}
44
45static int ihs_i2c_transfer(uchar chip, uchar *buffer, int len, bool read,
46 bool is_last)
47{
48 u16 val;
49
50 FPGA_SET_REG(I2C_ADAP_HWNR, i2c.interrupt_status, I2CINT_ERROR_EV
51 | I2CINT_RECEIVE_EV | I2CINT_TRANSMIT_EV);
52 FPGA_GET_REG(I2C_ADAP_HWNR, i2c.interrupt_status, &val);
53
54 if (!read && len) {
55 val = buffer[0];
56
57 if (len > 1)
58 val |= buffer[1] << 8;
59 FPGA_SET_REG(I2C_ADAP_HWNR, i2c.write_mailbox_ext, val);
60 }
61
62 FPGA_SET_REG(I2C_ADAP_HWNR, i2c.write_mailbox,
63 I2CMB_NATIVE
64 | (read ? 0 : I2CMB_WRITE)
65 | (chip << 1)
66 | ((len > 1) ? I2CMB_2BYTE : 0)
67 | (is_last ? 0 : I2CMB_HOLD_BUS));
68
69 if (wait_for_int(read))
70 return 1;
71
72 if (read) {
73 FPGA_GET_REG(I2C_ADAP_HWNR, i2c.read_mailbox_ext, &val);
74 buffer[0] = val & 0xff;
75 if (len > 1)
76 buffer[1] = val >> 8;
77 }
78
79 return 0;
80}
81
82static int ihs_i2c_address(uchar chip, uint addr, int alen, bool hold_bus)
83{
84 int shift = (alen-1) * 8;
85
86 while (alen) {
87 int transfer = MIN(alen, 2);
88 uchar buf[2];
89 bool is_last = alen <= transfer;
90
91 buf[0] = addr >> shift;
92 if (alen > 1)
93 buf[1] = addr >> (shift - 8);
94
95 if (ihs_i2c_transfer(chip, buf, transfer, false,
96 hold_bus ? false : is_last))
97 return 1;
98
99 shift -= 16;
100 alen -= transfer;
101 }
102
103 return 0;
104}
105
106static int ihs_i2c_access(struct i2c_adapter *adap, uchar chip, uint addr,
107 int alen, uchar *buffer, int len, bool read)
108{
109 if (len <= 0)
110 return 1;
111
112 if (ihs_i2c_address(chip, addr, alen, !read))
113 return 1;
114
115 while (len) {
116 int transfer = MIN(len, 2);
117
118 if (ihs_i2c_transfer(chip, buffer, transfer, read,
119 len <= transfer))
120 return 1;
121
122 buffer += transfer;
123 addr += transfer;
124 len -= transfer;
125 }
126
127 return 0;
128}
129
130
131static void ihs_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
132{
133#ifdef CONFIG_SYS_I2C_INIT_BOARD
134 /*
135 * Call board specific i2c bus reset routine before accessing the
136 * environment, which might be in a chip on that bus. For details
137 * about this problem see doc/I2C_Edge_Conditions.
138 */
139 i2c_init_board();
140#endif
141}
142
143static int ihs_i2c_probe(struct i2c_adapter *adap, uchar chip)
144{
145 uchar buffer[2];
146
147 if (ihs_i2c_transfer(chip, buffer, 0, true, true))
148 return 1;
149
150 return 0;
151}
152
153static int ihs_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
154 int alen, uchar *buffer, int len)
155{
156 return ihs_i2c_access(adap, chip, addr, alen, buffer, len, true);
157}
158
159static int ihs_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
160 int alen, uchar *buffer, int len)
161{
162 return ihs_i2c_access(adap, chip, addr, alen, buffer, len, false);
163}
164
165static unsigned int ihs_i2c_set_bus_speed(struct i2c_adapter *adap,
166 unsigned int speed)
167{
168 if (speed != adap->speed)
169 return 1;
170 return speed;
171}
172
173/*
174 * Register IHS i2c adapters
175 */
176#ifdef CONFIG_SYS_I2C_IHS_CH0
177U_BOOT_I2C_ADAP_COMPLETE(ihs0, ihs_i2c_init, ihs_i2c_probe,
178 ihs_i2c_read, ihs_i2c_write,
179 ihs_i2c_set_bus_speed,
180 CONFIG_SYS_I2C_IHS_SPEED_0,
181 CONFIG_SYS_I2C_IHS_SLAVE_0, 0)
182#endif
183#ifdef CONFIG_SYS_I2C_IHS_CH1
184U_BOOT_I2C_ADAP_COMPLETE(ihs1, ihs_i2c_init, ihs_i2c_probe,
185 ihs_i2c_read, ihs_i2c_write,
186 ihs_i2c_set_bus_speed,
187 CONFIG_SYS_I2C_IHS_SPEED_1,
188 CONFIG_SYS_I2C_IHS_SLAVE_1, 1)
189#endif
190#ifdef CONFIG_SYS_I2C_IHS_CH2
191U_BOOT_I2C_ADAP_COMPLETE(ihs2, ihs_i2c_init, ihs_i2c_probe,
192 ihs_i2c_read, ihs_i2c_write,
193 ihs_i2c_set_bus_speed,
194 CONFIG_SYS_I2C_IHS_SPEED_2,
195 CONFIG_SYS_I2C_IHS_SLAVE_2, 2)
196#endif
197#ifdef CONFIG_SYS_I2C_IHS_CH3
198U_BOOT_I2C_ADAP_COMPLETE(ihs3, ihs_i2c_init, ihs_i2c_probe,
199 ihs_i2c_read, ihs_i2c_write,
200 ihs_i2c_set_bus_speed,
201 CONFIG_SYS_I2C_IHS_SPEED_3,
202 CONFIG_SYS_I2C_IHS_SLAVE_3, 3)
203#endif