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 | |
28 | struct 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 | |
39 | static 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 | |
45 | static 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 | |
51 | static 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 | |
57 | static 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 | |
63 | static 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 | |
69 | static 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 | |
76 | static 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(100); |
95 | } while (ret); |
96 | } |
97 | |
98 | return ret > 0; |
99 | } |
100 | |
101 | static 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 | |
108 | static 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 | |
117 | static 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 | |
130 | static 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 | |
223 | static 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 |
231 | static const struct of_device_id i2c_pca_of_match_table[] = { |
232 | { .compatible = "nxp,pca9564" }, |
233 | { .compatible = "nxp,pca9665" }, |
234 | {}, |
235 | }; |
236 | MODULE_DEVICE_TABLE(of, i2c_pca_of_match_table); |
237 | #endif |
238 | |
239 | static struct platform_driver i2c_pca_pf_driver = { |
240 | .probe = i2c_pca_pf_probe, |
241 | .remove_new = 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 | |
248 | module_platform_driver(i2c_pca_pf_driver); |
249 | |
250 | MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>" ); |
251 | MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver" ); |
252 | MODULE_LICENSE("GPL" ); |
253 | |