1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * i2c_pca_platform.c
4 *
5 * Platform driver for the PCA9564 I2C controller.
6 *
7 * Copyright (C) 2008 Pengutronix
8 *
9
10 */
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/slab.h>
14#include <linux/delay.h>
15#include <linux/jiffies.h>
16#include <linux/errno.h>
17#include <linux/i2c.h>
18#include <linux/interrupt.h>
19#include <linux/platform_device.h>
20#include <linux/i2c-algo-pca.h>
21#include <linux/platform_data/i2c-pca-platform.h>
22#include <linux/gpio/consumer.h>
23#include <linux/io.h>
24#include <linux/of.h>
25
26#include <asm/irq.h>
27
28struct i2c_pca_pf_data {
29 void __iomem *reg_base;
30 int irq; /* if 0, use polling */
31 struct gpio_desc *gpio;
32 wait_queue_head_t wait;
33 struct i2c_adapter adap;
34 struct i2c_algo_pca_data algo_data;
35};
36
37/* Read/Write functions for different register alignments */
38
39static int i2c_pca_pf_readbyte8(void *pd, int reg)
40{
41 struct i2c_pca_pf_data *i2c = pd;
42 return ioread8(i2c->reg_base + reg);
43}
44
45static int i2c_pca_pf_readbyte16(void *pd, int reg)
46{
47 struct i2c_pca_pf_data *i2c = pd;
48 return ioread8(i2c->reg_base + reg * 2);
49}
50
51static int i2c_pca_pf_readbyte32(void *pd, int reg)
52{
53 struct i2c_pca_pf_data *i2c = pd;
54 return ioread8(i2c->reg_base + reg * 4);
55}
56
57static void i2c_pca_pf_writebyte8(void *pd, int reg, int val)
58{
59 struct i2c_pca_pf_data *i2c = pd;
60 iowrite8(val, i2c->reg_base + reg);
61}
62
63static void i2c_pca_pf_writebyte16(void *pd, int reg, int val)
64{
65 struct i2c_pca_pf_data *i2c = pd;
66 iowrite8(val, i2c->reg_base + reg * 2);
67}
68
69static void i2c_pca_pf_writebyte32(void *pd, int reg, int val)
70{
71 struct i2c_pca_pf_data *i2c = pd;
72 iowrite8(val, i2c->reg_base + reg * 4);
73}
74
75
76static int i2c_pca_pf_waitforcompletion(void *pd)
77{
78 struct i2c_pca_pf_data *i2c = pd;
79 unsigned long timeout;
80 long ret;
81
82 if (i2c->irq) {
83 ret = wait_event_timeout(i2c->wait,
84 i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
85 & I2C_PCA_CON_SI, i2c->adap.timeout);
86 } else {
87 /* Do polling */
88 timeout = jiffies + i2c->adap.timeout;
89 do {
90 ret = time_before(jiffies, timeout);
91 if (i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
92 & I2C_PCA_CON_SI)
93 break;
94 udelay(usec: 100);
95 } while (ret);
96 }
97
98 return ret > 0;
99}
100
101static void i2c_pca_pf_dummyreset(void *pd)
102{
103 struct i2c_pca_pf_data *i2c = pd;
104
105 dev_warn(&i2c->adap.dev, "No reset-pin found. Chip may get stuck!\n");
106}
107
108static void i2c_pca_pf_resetchip(void *pd)
109{
110 struct i2c_pca_pf_data *i2c = pd;
111
112 gpiod_set_value(desc: i2c->gpio, value: 1);
113 ndelay(100);
114 gpiod_set_value(desc: i2c->gpio, value: 0);
115}
116
117static irqreturn_t i2c_pca_pf_handler(int this_irq, void *dev_id)
118{
119 struct i2c_pca_pf_data *i2c = dev_id;
120
121 if ((i2c->algo_data.read_byte(i2c, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0)
122 return IRQ_NONE;
123
124 wake_up(&i2c->wait);
125
126 return IRQ_HANDLED;
127}
128
129
130static int i2c_pca_pf_probe(struct platform_device *pdev)
131{
132 struct i2c_pca_pf_data *i2c;
133 struct resource *res;
134 struct i2c_pca9564_pf_platform_data *platform_data =
135 dev_get_platdata(dev: &pdev->dev);
136 struct device_node *np = pdev->dev.of_node;
137 int ret = 0;
138 int irq;
139
140 irq = platform_get_irq_optional(pdev, 0);
141 /* If irq is 0, we do polling. */
142 if (irq < 0)
143 irq = 0;
144
145 i2c = devm_kzalloc(dev: &pdev->dev, size: sizeof(*i2c), GFP_KERNEL);
146 if (!i2c)
147 return -ENOMEM;
148
149 i2c->reg_base = devm_platform_get_and_ioremap_resource(pdev, index: 0, res: &res);
150 if (IS_ERR(ptr: i2c->reg_base))
151 return PTR_ERR(ptr: i2c->reg_base);
152
153
154 init_waitqueue_head(&i2c->wait);
155
156 i2c->irq = irq;
157
158 i2c->adap.nr = pdev->id;
159 i2c->adap.owner = THIS_MODULE;
160 snprintf(buf: i2c->adap.name, size: sizeof(i2c->adap.name),
161 fmt: "PCA9564/PCA9665 at 0x%08lx",
162 (unsigned long) res->start);
163 i2c->adap.algo_data = &i2c->algo_data;
164 i2c->adap.dev.parent = &pdev->dev;
165 i2c->adap.dev.of_node = np;
166
167 i2c->gpio = devm_gpiod_get_optional(dev: &pdev->dev, con_id: "reset", flags: GPIOD_OUT_LOW);
168 if (IS_ERR(ptr: i2c->gpio))
169 return PTR_ERR(ptr: i2c->gpio);
170
171 i2c->adap.timeout = HZ;
172 ret = device_property_read_u32(dev: &pdev->dev, propname: "clock-frequency",
173 val: &i2c->algo_data.i2c_clock);
174 if (ret)
175 i2c->algo_data.i2c_clock = 59000;
176
177 if (platform_data) {
178 i2c->adap.timeout = platform_data->timeout;
179 i2c->algo_data.i2c_clock = platform_data->i2c_clock_speed;
180 }
181
182 i2c->algo_data.data = i2c;
183 i2c->algo_data.wait_for_completion = i2c_pca_pf_waitforcompletion;
184 if (i2c->gpio)
185 i2c->algo_data.reset_chip = i2c_pca_pf_resetchip;
186 else
187 i2c->algo_data.reset_chip = i2c_pca_pf_dummyreset;
188
189 switch (res->flags & IORESOURCE_MEM_TYPE_MASK) {
190 case IORESOURCE_MEM_32BIT:
191 i2c->algo_data.write_byte = i2c_pca_pf_writebyte32;
192 i2c->algo_data.read_byte = i2c_pca_pf_readbyte32;
193 break;
194 case IORESOURCE_MEM_16BIT:
195 i2c->algo_data.write_byte = i2c_pca_pf_writebyte16;
196 i2c->algo_data.read_byte = i2c_pca_pf_readbyte16;
197 break;
198 case IORESOURCE_MEM_8BIT:
199 default:
200 i2c->algo_data.write_byte = i2c_pca_pf_writebyte8;
201 i2c->algo_data.read_byte = i2c_pca_pf_readbyte8;
202 break;
203 }
204
205 if (irq) {
206 ret = devm_request_irq(dev: &pdev->dev, irq, handler: i2c_pca_pf_handler,
207 IRQF_TRIGGER_FALLING, devname: pdev->name, dev_id: i2c);
208 if (ret)
209 return ret;
210 }
211
212 ret = i2c_pca_add_numbered_bus(&i2c->adap);
213 if (ret)
214 return ret;
215
216 platform_set_drvdata(pdev, data: i2c);
217
218 dev_info(&pdev->dev, "registered.\n");
219
220 return 0;
221}
222
223static void i2c_pca_pf_remove(struct platform_device *pdev)
224{
225 struct i2c_pca_pf_data *i2c = platform_get_drvdata(pdev);
226
227 i2c_del_adapter(adap: &i2c->adap);
228}
229
230#ifdef CONFIG_OF
231static const struct of_device_id i2c_pca_of_match_table[] = {
232 { .compatible = "nxp,pca9564" },
233 { .compatible = "nxp,pca9665" },
234 {},
235};
236MODULE_DEVICE_TABLE(of, i2c_pca_of_match_table);
237#endif
238
239static struct platform_driver i2c_pca_pf_driver = {
240 .probe = i2c_pca_pf_probe,
241 .remove = i2c_pca_pf_remove,
242 .driver = {
243 .name = "i2c-pca-platform",
244 .of_match_table = of_match_ptr(i2c_pca_of_match_table),
245 },
246};
247
248module_platform_driver(i2c_pca_pf_driver);
249
250MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>");
251MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver");
252MODULE_LICENSE("GPL");
253

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source code of linux/drivers/i2c/busses/i2c-pca-platform.c