1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * i2c-pca-isa.c driver for PCA9564 on ISA boards |
4 | * Copyright (C) 2004 Arcom Control Systems |
5 | * Copyright (C) 2008 Pengutronix |
6 | */ |
7 | |
8 | #include <linux/kernel.h> |
9 | #include <linux/ioport.h> |
10 | #include <linux/module.h> |
11 | #include <linux/moduleparam.h> |
12 | #include <linux/delay.h> |
13 | #include <linux/jiffies.h> |
14 | #include <linux/init.h> |
15 | #include <linux/interrupt.h> |
16 | #include <linux/wait.h> |
17 | #include <linux/isa.h> |
18 | #include <linux/i2c.h> |
19 | #include <linux/i2c-algo-pca.h> |
20 | #include <linux/io.h> |
21 | |
22 | #include <asm/irq.h> |
23 | |
24 | #define DRIVER "i2c-pca-isa" |
25 | #define IO_SIZE 4 |
26 | |
27 | static unsigned long base; |
28 | static int irq = -1; |
29 | |
30 | /* Data sheet recommends 59kHz for 100kHz operation due to variation |
31 | * in the actual clock rate */ |
32 | static int clock = 59000; |
33 | |
34 | static struct i2c_adapter pca_isa_ops; |
35 | static wait_queue_head_t pca_wait; |
36 | |
37 | static void pca_isa_writebyte(void *pd, int reg, int val) |
38 | { |
39 | #ifdef DEBUG_IO |
40 | static char *names[] = { "T/O" , "DAT" , "ADR" , "CON" }; |
41 | printk(KERN_DEBUG "*** write %s at %#lx <= %#04x\n" , names[reg], |
42 | base+reg, val); |
43 | #endif |
44 | outb(value: val, port: base+reg); |
45 | } |
46 | |
47 | static int pca_isa_readbyte(void *pd, int reg) |
48 | { |
49 | int res = inb(port: base+reg); |
50 | #ifdef DEBUG_IO |
51 | { |
52 | static char *names[] = { "STA" , "DAT" , "ADR" , "CON" }; |
53 | printk(KERN_DEBUG "*** read %s => %#04x\n" , names[reg], res); |
54 | } |
55 | #endif |
56 | return res; |
57 | } |
58 | |
59 | static int pca_isa_waitforcompletion(void *pd) |
60 | { |
61 | unsigned long timeout; |
62 | long ret; |
63 | |
64 | if (irq > -1) { |
65 | ret = wait_event_timeout(pca_wait, |
66 | pca_isa_readbyte(pd, I2C_PCA_CON) |
67 | & I2C_PCA_CON_SI, pca_isa_ops.timeout); |
68 | } else { |
69 | /* Do polling */ |
70 | timeout = jiffies + pca_isa_ops.timeout; |
71 | do { |
72 | ret = time_before(jiffies, timeout); |
73 | if (pca_isa_readbyte(pd, I2C_PCA_CON) |
74 | & I2C_PCA_CON_SI) |
75 | break; |
76 | udelay(100); |
77 | } while (ret); |
78 | } |
79 | |
80 | return ret > 0; |
81 | } |
82 | |
83 | static void pca_isa_resetchip(void *pd) |
84 | { |
85 | /* apparently only an external reset will do it. not a lot can be done */ |
86 | printk(KERN_WARNING DRIVER ": Haven't figured out how to do a reset yet\n" ); |
87 | } |
88 | |
89 | static irqreturn_t pca_handler(int this_irq, void *dev_id) { |
90 | wake_up(&pca_wait); |
91 | return IRQ_HANDLED; |
92 | } |
93 | |
94 | static struct i2c_algo_pca_data pca_isa_data = { |
95 | /* .data intentionally left NULL, not needed with ISA */ |
96 | .write_byte = pca_isa_writebyte, |
97 | .read_byte = pca_isa_readbyte, |
98 | .wait_for_completion = pca_isa_waitforcompletion, |
99 | .reset_chip = pca_isa_resetchip, |
100 | }; |
101 | |
102 | static struct i2c_adapter pca_isa_ops = { |
103 | .owner = THIS_MODULE, |
104 | .algo_data = &pca_isa_data, |
105 | .name = "PCA9564/PCA9665 ISA Adapter" , |
106 | .timeout = HZ, |
107 | }; |
108 | |
109 | static int pca_isa_match(struct device *dev, unsigned int id) |
110 | { |
111 | int match = base != 0; |
112 | |
113 | if (match) { |
114 | if (irq <= -1) |
115 | dev_warn(dev, "Using polling mode (specify irq)\n" ); |
116 | } else |
117 | dev_err(dev, "Please specify I/O base\n" ); |
118 | |
119 | return match; |
120 | } |
121 | |
122 | static int pca_isa_probe(struct device *dev, unsigned int id) |
123 | { |
124 | init_waitqueue_head(&pca_wait); |
125 | |
126 | dev_info(dev, "i/o base %#08lx. irq %d\n" , base, irq); |
127 | |
128 | #ifdef CONFIG_PPC |
129 | if (check_legacy_ioport(base)) { |
130 | dev_err(dev, "I/O address %#08lx is not available\n" , base); |
131 | goto out; |
132 | } |
133 | #endif |
134 | |
135 | if (!request_region(base, IO_SIZE, "i2c-pca-isa" )) { |
136 | dev_err(dev, "I/O address %#08lx is in use\n" , base); |
137 | goto out; |
138 | } |
139 | |
140 | if (irq > -1) { |
141 | if (request_irq(irq, handler: pca_handler, flags: 0, name: "i2c-pca-isa" , dev: &pca_isa_ops) < 0) { |
142 | dev_err(dev, "Request irq%d failed\n" , irq); |
143 | goto out_region; |
144 | } |
145 | } |
146 | |
147 | pca_isa_data.i2c_clock = clock; |
148 | if (i2c_pca_add_bus(&pca_isa_ops) < 0) { |
149 | dev_err(dev, "Failed to add i2c bus\n" ); |
150 | goto out_irq; |
151 | } |
152 | |
153 | return 0; |
154 | |
155 | out_irq: |
156 | if (irq > -1) |
157 | free_irq(irq, &pca_isa_ops); |
158 | out_region: |
159 | release_region(base, IO_SIZE); |
160 | out: |
161 | return -ENODEV; |
162 | } |
163 | |
164 | static void pca_isa_remove(struct device *dev, unsigned int id) |
165 | { |
166 | i2c_del_adapter(adap: &pca_isa_ops); |
167 | |
168 | if (irq > -1) { |
169 | disable_irq(irq); |
170 | free_irq(irq, &pca_isa_ops); |
171 | } |
172 | release_region(base, IO_SIZE); |
173 | } |
174 | |
175 | static struct isa_driver pca_isa_driver = { |
176 | .match = pca_isa_match, |
177 | .probe = pca_isa_probe, |
178 | .remove = pca_isa_remove, |
179 | .driver = { |
180 | .owner = THIS_MODULE, |
181 | .name = DRIVER, |
182 | } |
183 | }; |
184 | |
185 | MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>" ); |
186 | MODULE_DESCRIPTION("ISA base PCA9564/PCA9665 driver" ); |
187 | MODULE_LICENSE("GPL" ); |
188 | |
189 | module_param_hw(base, ulong, ioport, 0); |
190 | MODULE_PARM_DESC(base, "I/O base address" ); |
191 | module_param_hw(irq, int, irq, 0); |
192 | MODULE_PARM_DESC(irq, "IRQ" ); |
193 | module_param(clock, int, 0); |
194 | MODULE_PARM_DESC(clock, "Clock rate in hertz.\n\t\t" |
195 | "For PCA9564: 330000,288000,217000,146000," |
196 | "88000,59000,44000,36000\n" |
197 | "\t\tFor PCA9665:\tStandard: 60300 - 100099\n" |
198 | "\t\t\t\tFast: 100100 - 400099\n" |
199 | "\t\t\t\tFast+: 400100 - 10000099\n" |
200 | "\t\t\t\tTurbo: Up to 1265800" ); |
201 | module_isa_driver(pca_isa_driver, 1); |
202 | |