aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/i2c/busses/i2c-gpio.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/i2c/busses/i2c-gpio.c')
-rw-r--r--drivers/i2c/busses/i2c-gpio.c98
1 files changed, 76 insertions, 22 deletions
diff --git a/drivers/i2c/busses/i2c-gpio.c b/drivers/i2c/busses/i2c-gpio.c
index a651779d9ff7..c0330a41db03 100644
--- a/drivers/i2c/busses/i2c-gpio.c
+++ b/drivers/i2c/busses/i2c-gpio.c
@@ -14,8 +14,15 @@
14#include <linux/module.h> 14#include <linux/module.h>
15#include <linux/slab.h> 15#include <linux/slab.h>
16#include <linux/platform_device.h> 16#include <linux/platform_device.h>
17 17#include <linux/gpio.h>
18#include <asm/gpio.h> 18#include <linux/of_gpio.h>
19#include <linux/of_i2c.h>
20
21struct i2c_gpio_private_data {
22 struct i2c_adapter adap;
23 struct i2c_algo_bit_data bit_data;
24 struct i2c_gpio_platform_data pdata;
25};
19 26
20/* Toggle SDA by changing the direction of the pin */ 27/* Toggle SDA by changing the direction of the pin */
21static void i2c_gpio_setsda_dir(void *data, int state) 28static void i2c_gpio_setsda_dir(void *data, int state)
@@ -78,24 +85,62 @@ static int i2c_gpio_getscl(void *data)
78 return gpio_get_value(pdata->scl_pin); 85 return gpio_get_value(pdata->scl_pin);
79} 86}
80 87
88static int __devinit of_i2c_gpio_probe(struct device_node *np,
89 struct i2c_gpio_platform_data *pdata)
90{
91 u32 reg;
92
93 if (of_gpio_count(np) < 2)
94 return -ENODEV;
95
96 pdata->sda_pin = of_get_gpio(np, 0);
97 pdata->scl_pin = of_get_gpio(np, 1);
98
99 if (!gpio_is_valid(pdata->sda_pin) || !gpio_is_valid(pdata->scl_pin)) {
100 pr_err("%s: invalid GPIO pins, sda=%d/scl=%d\n",
101 np->full_name, pdata->sda_pin, pdata->scl_pin);
102 return -ENODEV;
103 }
104
105 of_property_read_u32(np, "i2c-gpio,delay-us", &pdata->udelay);
106
107 if (!of_property_read_u32(np, "i2c-gpio,timeout-ms", &reg))
108 pdata->timeout = msecs_to_jiffies(reg);
109
110 pdata->sda_is_open_drain =
111 of_property_read_bool(np, "i2c-gpio,sda-open-drain");
112 pdata->scl_is_open_drain =
113 of_property_read_bool(np, "i2c-gpio,scl-open-drain");
114 pdata->scl_is_output_only =
115 of_property_read_bool(np, "i2c-gpio,scl-output-only");
116
117 return 0;
118}
119
81static int __devinit i2c_gpio_probe(struct platform_device *pdev) 120static int __devinit i2c_gpio_probe(struct platform_device *pdev)
82{ 121{
122 struct i2c_gpio_private_data *priv;
83 struct i2c_gpio_platform_data *pdata; 123 struct i2c_gpio_platform_data *pdata;
84 struct i2c_algo_bit_data *bit_data; 124 struct i2c_algo_bit_data *bit_data;
85 struct i2c_adapter *adap; 125 struct i2c_adapter *adap;
86 int ret; 126 int ret;
87 127
88 pdata = pdev->dev.platform_data; 128 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
89 if (!pdata) 129 if (!priv)
90 return -ENXIO; 130 return -ENOMEM;
91 131 adap = &priv->adap;
92 ret = -ENOMEM; 132 bit_data = &priv->bit_data;
93 adap = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL); 133 pdata = &priv->pdata;
94 if (!adap) 134
95 goto err_alloc_adap; 135 if (pdev->dev.of_node) {
96 bit_data = kzalloc(sizeof(struct i2c_algo_bit_data), GFP_KERNEL); 136 ret = of_i2c_gpio_probe(pdev->dev.of_node, pdata);
97 if (!bit_data) 137 if (ret)
98 goto err_alloc_bit_data; 138 return ret;
139 } else {
140 if (!pdev->dev.platform_data)
141 return -ENXIO;
142 memcpy(pdata, pdev->dev.platform_data, sizeof(*pdata));
143 }
99 144
100 ret = gpio_request(pdata->sda_pin, "sda"); 145 ret = gpio_request(pdata->sda_pin, "sda");
101 if (ret) 146 if (ret)
@@ -143,6 +188,7 @@ static int __devinit i2c_gpio_probe(struct platform_device *pdev)
143 adap->algo_data = bit_data; 188 adap->algo_data = bit_data;
144 adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD; 189 adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
145 adap->dev.parent = &pdev->dev; 190 adap->dev.parent = &pdev->dev;
191 adap->dev.of_node = pdev->dev.of_node;
146 192
147 /* 193 /*
148 * If "dev->id" is negative we consider it as zero. 194 * If "dev->id" is negative we consider it as zero.
@@ -154,7 +200,9 @@ static int __devinit i2c_gpio_probe(struct platform_device *pdev)
154 if (ret) 200 if (ret)
155 goto err_add_bus; 201 goto err_add_bus;
156 202
157 platform_set_drvdata(pdev, adap); 203 of_i2c_register_devices(adap);
204
205 platform_set_drvdata(pdev, priv);
158 206
159 dev_info(&pdev->dev, "using pins %u (SDA) and %u (SCL%s)\n", 207 dev_info(&pdev->dev, "using pins %u (SDA) and %u (SCL%s)\n",
160 pdata->sda_pin, pdata->scl_pin, 208 pdata->sda_pin, pdata->scl_pin,
@@ -168,34 +216,40 @@ err_add_bus:
168err_request_scl: 216err_request_scl:
169 gpio_free(pdata->sda_pin); 217 gpio_free(pdata->sda_pin);
170err_request_sda: 218err_request_sda:
171 kfree(bit_data);
172err_alloc_bit_data:
173 kfree(adap);
174err_alloc_adap:
175 return ret; 219 return ret;
176} 220}
177 221
178static int __devexit i2c_gpio_remove(struct platform_device *pdev) 222static int __devexit i2c_gpio_remove(struct platform_device *pdev)
179{ 223{
224 struct i2c_gpio_private_data *priv;
180 struct i2c_gpio_platform_data *pdata; 225 struct i2c_gpio_platform_data *pdata;
181 struct i2c_adapter *adap; 226 struct i2c_adapter *adap;
182 227
183 adap = platform_get_drvdata(pdev); 228 priv = platform_get_drvdata(pdev);
184 pdata = pdev->dev.platform_data; 229 adap = &priv->adap;
230 pdata = &priv->pdata;
185 231
186 i2c_del_adapter(adap); 232 i2c_del_adapter(adap);
187 gpio_free(pdata->scl_pin); 233 gpio_free(pdata->scl_pin);
188 gpio_free(pdata->sda_pin); 234 gpio_free(pdata->sda_pin);
189 kfree(adap->algo_data);
190 kfree(adap);
191 235
192 return 0; 236 return 0;
193} 237}
194 238
239#if defined(CONFIG_OF)
240static const struct of_device_id i2c_gpio_dt_ids[] = {
241 { .compatible = "i2c-gpio", },
242 { /* sentinel */ }
243};
244
245MODULE_DEVICE_TABLE(of, i2c_gpio_dt_ids);
246#endif
247
195static struct platform_driver i2c_gpio_driver = { 248static struct platform_driver i2c_gpio_driver = {
196 .driver = { 249 .driver = {
197 .name = "i2c-gpio", 250 .name = "i2c-gpio",
198 .owner = THIS_MODULE, 251 .owner = THIS_MODULE,
252 .of_match_table = of_match_ptr(i2c_gpio_dt_ids),
199 }, 253 },
200 .probe = i2c_gpio_probe, 254 .probe = i2c_gpio_probe,
201 .remove = __devexit_p(i2c_gpio_remove), 255 .remove = __devexit_p(i2c_gpio_remove),