[PATCH 2/2] Platform: x86: chromeos_laptop - Use deferred probing

From: Benson Leung
Date: Wed Jul 17 2013 - 20:21:43 EST


Further refactor chromeos_laptop, adding a probe function.
Init will call dmi_check_system, but will only use the match to select
a chromeos_laptop structure of the current board.

Probe will add the devices, and on errors return -EPROBE_DEFER.
If i2c adapters are loaded after chromeos_laptop inits, the deferred
probe will instantiate the peripherals when the bus appears.

Signed-off-by: Benson Leung <bleung@xxxxxxxxxxxx>
---
drivers/platform/x86/chromeos_laptop.c | 139 +++++++++++++++++++++++----------
1 file changed, 98 insertions(+), 41 deletions(-)

diff --git a/drivers/platform/x86/chromeos_laptop.c b/drivers/platform/x86/chromeos_laptop.c
index 086f347..fc64f65 100644
--- a/drivers/platform/x86/chromeos_laptop.c
+++ b/drivers/platform/x86/chromeos_laptop.c
@@ -27,6 +27,7 @@
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/module.h>
+#include <linux/platform_device.h>

#define ATMEL_TP_I2C_ADDR 0x4b
#define ATMEL_TP_I2C_BL_ADDR 0x25
@@ -54,7 +55,7 @@ enum i2c_adapter_type {
};

struct i2c_peripheral {
- void (*add)(enum i2c_adapter_type type);
+ int (*add)(enum i2c_adapter_type type);
enum i2c_adapter_type type;
};

@@ -64,20 +65,22 @@ struct chromeos_laptop {
struct i2c_peripheral i2c_peripherals[MAX_I2C_PERIPHERALS];
};

-static struct i2c_board_info __initdata cyapa_device = {
+static struct chromeos_laptop *cros_laptop;
+
+static struct i2c_board_info cyapa_device = {
I2C_BOARD_INFO("cyapa", CYAPA_TP_I2C_ADDR),
.flags = I2C_CLIENT_WAKE,
};

-static struct i2c_board_info __initdata isl_als_device = {
+static struct i2c_board_info isl_als_device = {
I2C_BOARD_INFO("isl29018", ISL_ALS_I2C_ADDR),
};

-static struct i2c_board_info __initdata tsl2583_als_device = {
+static struct i2c_board_info tsl2583_als_device = {
I2C_BOARD_INFO("tsl2583", TAOS_ALS_I2C_ADDR),
};

-static struct i2c_board_info __initdata tsl2563_als_device = {
+static struct i2c_board_info tsl2563_als_device = {
I2C_BOARD_INFO("tsl2563", TAOS_ALS_I2C_ADDR),
};

@@ -100,7 +103,7 @@ static struct mxt_platform_data atmel_224s_tp_platform_data = {
.config_length = 0,
};

-static struct i2c_board_info __initdata atmel_224s_tp_device = {
+static struct i2c_board_info atmel_224s_tp_device = {
I2C_BOARD_INFO("atmel_mxt_tp", ATMEL_TP_I2C_ADDR),
.platform_data = &atmel_224s_tp_platform_data,
.flags = I2C_CLIENT_WAKE,
@@ -121,13 +124,13 @@ static struct mxt_platform_data atmel_1664s_platform_data = {
.config_length = 0,
};

-static struct i2c_board_info __initdata atmel_1664s_device = {
+static struct i2c_board_info atmel_1664s_device = {
I2C_BOARD_INFO("atmel_mxt_ts", ATMEL_TS_I2C_ADDR),
.platform_data = &atmel_1664s_platform_data,
.flags = I2C_CLIENT_WAKE,
};

-static struct i2c_client __init *__add_probed_i2c_device(
+static struct i2c_client *__add_probed_i2c_device(
const char *name,
int bus,
struct i2c_board_info *info,
@@ -180,7 +183,7 @@ static struct i2c_client __init *__add_probed_i2c_device(
return client;
}

-static int __init __find_i2c_adap(struct device *dev, void *data)
+static int __find_i2c_adap(struct device *dev, void *data)
{
const char *name = data;
static const char *prefix = "i2c-";
@@ -191,7 +194,7 @@ static int __init __find_i2c_adap(struct device *dev, void *data)
return (strncmp(adapter->name, name, strlen(name)) == 0);
}

-static int __init find_i2c_adapter_num(enum i2c_adapter_type type)
+static int find_i2c_adapter_num(enum i2c_adapter_type type)
{
struct device *dev = NULL;
struct i2c_adapter *adapter;
@@ -216,7 +219,7 @@ static int __init find_i2c_adapter_num(enum i2c_adapter_type type)
* Returns NULL if no devices found.
* See Documentation/i2c/instantiating-devices for more information.
*/
-static __init struct i2c_client *add_probed_i2c_device(
+static struct i2c_client *add_probed_i2c_device(
const char *name,
enum i2c_adapter_type type,
struct i2c_board_info *info,
@@ -233,7 +236,7 @@ static __init struct i2c_client *add_probed_i2c_device(
* info->addr.
* Returns NULL if no device found.
*/
-static __init struct i2c_client *add_i2c_device(const char *name,
+static struct i2c_client *add_i2c_device(const char *name,
enum i2c_adapter_type type,
struct i2c_board_info *info)
{
@@ -244,65 +247,87 @@ static __init struct i2c_client *add_i2c_device(const char *name,
addr_list);
}

-static int __init setup_cyapa_tp(enum i2c_adapter_type type)
+static int setup_cyapa_tp(enum i2c_adapter_type type)
{
+ if (tp)
+ return 0;
+
/* add cyapa touchpad */
tp = add_i2c_device("trackpad", type, &cyapa_device);
- return 0;
+ return (!tp) ? -EAGAIN : 0;
}

-static int __init setup_atmel_224s_tp(enum i2c_adapter_type type)
+static int setup_atmel_224s_tp(enum i2c_adapter_type type)
{
const unsigned short addr_list[] = { ATMEL_TP_I2C_BL_ADDR,
ATMEL_TP_I2C_ADDR,
I2C_CLIENT_END };
+ if (tp)
+ return 0;

/* add atmel mxt touchpad */
tp = add_probed_i2c_device("trackpad", type,
&atmel_224s_tp_device, addr_list);
- return 0;
+ return (!tp) ? -EAGAIN : 0;
}

-static int __init setup_atmel_1664s_ts(enum i2c_adapter_type type)
+static int setup_atmel_1664s_ts(enum i2c_adapter_type type)
{
const unsigned short addr_list[] = { ATMEL_TS_I2C_BL_ADDR,
ATMEL_TS_I2C_ADDR,
I2C_CLIENT_END };
+ if (ts)
+ return 0;

/* add atmel mxt touch device */
ts = add_probed_i2c_device("touchscreen", type,
&atmel_1664s_device, addr_list);
- return 0;
+ return (!ts) ? -EAGAIN : 0;
}

-static int __init setup_isl29018_als(enum i2c_adapter_type type)
+static int setup_isl29018_als(enum i2c_adapter_type type)
{
+ if (als)
+ return 0;
+
/* add isl29018 light sensor */
als = add_i2c_device("lightsensor", type, &isl_als_device);
- return 0;
+ return (!als) ? -EAGAIN : 0;
}

-static int __init setup_tsl2583_als(enum i2c_adapter_type type)
+static int setup_tsl2583_als(enum i2c_adapter_type type)
{
+ if (als)
+ return 0;
+
/* add tsl2583 light sensor */
als = add_i2c_device(NULL, type, &tsl2583_als_device);
- return 0;
+ return (!als) ? -EAGAIN : 0;
}

-static int __init setup_tsl2563_als(enum i2c_adapter_type type)
+static int setup_tsl2563_als(enum i2c_adapter_type type)
{
+ if (als)
+ return 0;
+
/* add tsl2563 light sensor */
als = add_i2c_device(NULL, type, &tsl2563_als_device);
- return 0;
+ return (!als) ? -EAGAIN : 0;
}

-static int __init
-chromeos_laptop_add_peripherals(const struct dmi_system_id *id)
+static int __init chromeos_laptop_dmi_matched(const struct dmi_system_id *id)
{
- int i;
- struct chromeos_laptop *cros_laptop = (void *)id->driver_data;
+ cros_laptop = (void *)id->driver_data;
+ pr_debug("DMI Matched %s.\n", id->ident);

- pr_debug("Adding peripherals for %s.\n", id->ident);
+ /* Indicate to dmi_scan that processing is done. */
+ return 1;
+}
+
+static int chromeos_laptop_probe(struct platform_device *pdev)
+{
+ int i;
+ int ret = 0;

for (i = 0; i < MAX_I2C_PERIPHERALS; i++) {
struct i2c_peripheral *i2c_dev;
@@ -313,15 +338,15 @@ chromeos_laptop_add_peripherals(const struct dmi_system_id *id)
if (i2c_dev->add == NULL)
break;

- /* Add the device. */
- i2c_dev->add(i2c_dev->type);
+ /* Add the device. Set -EPROBE_DEFER on any failure */
+ if (i2c_dev->add(i2c_dev->type))
+ ret = -EPROBE_DEFER;
}

- /* Indicate to dmi_scan that processing is done. */
- return 1;
+ return ret;
}

-static struct chromeos_laptop __initdata samsung_series_5_550 = {
+static struct chromeos_laptop samsung_series_5_550 = {
.i2c_peripherals = {
/* Touchpad. */
{ .add = setup_cyapa_tp, I2C_ADAPTER_SMBUS },
@@ -330,14 +355,14 @@ static struct chromeos_laptop __initdata samsung_series_5_550 = {
},
};

-static struct chromeos_laptop __initdata samsung_series_5 = {
+static struct chromeos_laptop samsung_series_5 = {
.i2c_peripherals = {
/* Light Sensor. */
{ .add = setup_tsl2583_als, I2C_ADAPTER_SMBUS },
},
};

-static struct chromeos_laptop __initdata chromebook_pixel = {
+static struct chromeos_laptop chromebook_pixel = {
.i2c_peripherals = {
/* Touch Screen. */
{ .add = setup_atmel_1664s_ts, I2C_ADAPTER_PANEL },
@@ -348,28 +373,28 @@ static struct chromeos_laptop __initdata chromebook_pixel = {
},
};

-static struct chromeos_laptop __initdata acer_c7_chromebook = {
+static struct chromeos_laptop acer_c7_chromebook = {
.i2c_peripherals = {
/* Touchpad. */
{ .add = setup_cyapa_tp, I2C_ADAPTER_SMBUS },
},
};

-static struct chromeos_laptop __initdata acer_ac700 = {
+static struct chromeos_laptop acer_ac700 = {
.i2c_peripherals = {
/* Light Sensor. */
{ .add = setup_tsl2563_als, I2C_ADAPTER_SMBUS },
},
};

-static struct chromeos_laptop __initdata hp_pavilion_14_chromebook = {
+static struct chromeos_laptop hp_pavilion_14_chromebook = {
.i2c_peripherals = {
/* Touchpad. */
{ .add = setup_cyapa_tp, I2C_ADAPTER_SMBUS },
},
};

-static struct chromeos_laptop __initdata cr48 = {
+static struct chromeos_laptop cr48 = {
.i2c_peripherals = {
/* Light Sensor. */
{ .add = setup_tsl2563_als, I2C_ADAPTER_SMBUS },
@@ -377,7 +402,7 @@ static struct chromeos_laptop __initdata cr48 = {
};

#define _CBDD(board_) \
- .callback = &chromeos_laptop_add_peripherals, \
+ .callback = chromeos_laptop_dmi_matched, \
.driver_data = (void *)&board_

static struct dmi_system_id __initdata chromeos_laptop_dmi_table[] = {
@@ -436,13 +461,45 @@ static struct dmi_system_id __initdata chromeos_laptop_dmi_table[] = {
};
MODULE_DEVICE_TABLE(dmi, chromeos_laptop_dmi_table);

+static struct platform_device *cros_platform_device;
+
+static struct platform_driver cros_platform_driver = {
+ .driver = {
+ .name = "chromeos_laptop",
+ .owner = THIS_MODULE,
+ },
+ .probe = chromeos_laptop_probe,
+};
+
static int __init chromeos_laptop_init(void)
{
+ int ret;
if (!dmi_check_system(chromeos_laptop_dmi_table)) {
pr_debug("%s unsupported system.\n", __func__);
return -ENODEV;
}
+
+ ret = platform_driver_register(&cros_platform_driver);
+ if (ret)
+ return ret;
+
+ cros_platform_device = platform_device_alloc("chromeos_laptop", -1);
+ if (!cros_platform_device) {
+ ret = -ENOMEM;
+ goto fail_platform_device1;
+ }
+
+ ret = platform_device_add(cros_platform_device);
+ if (ret)
+ goto fail_platform_device2;
+
return 0;
+
+fail_platform_device2:
+ platform_device_put(cros_platform_device);
+fail_platform_device1:
+ platform_driver_unregister(&cros_platform_driver);
+ return ret;
}

static void __exit chromeos_laptop_exit(void)
--
1.8.3

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