platform/chrome: chromeos_laptop - Use deferred probing

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@chromium.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Signed-off-by: Olof Johansson <olof@lixom.net>

1 files changed, 101 insertions, 43 deletions

diff --git a/drivers/platform/chrome/chromeos_laptop.c b/drivers/platform/chrome/chromeos_laptop.c
index 5c69cfd97ff0..e542330f8048 100644
--- a/drivers/platform/chrome/chromeos_laptop.c
+++ b/drivers/platform/chrome/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;
@@ -200,8 +203,9 @@ static int __init find_i2c_adapter_num(enum i2c_adapter_type type)
         dev = bus_find_device(&i2c_bus_type, NULL, (void *)name,
                               __find_i2c_adap);
         if (!dev) {
-                pr_err("%s: i2c adapter %s not found on system.\n", __func__,
-                       name);
+                /* Adapters may appear later. Deferred probing will retry */
+                pr_notice("%s: i2c adapter %s not found on system.\n", __func__,
+                          name);
                 return -ENODEV;
         }
         adapter = to_i2c_adapter(dev);
@@ -216,7 +220,7 @@ 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 +237,7 @@ 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 +248,87 @@ 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 +339,15 @@ 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 samsung_series_5_550 __initdata = {
+static struct chromeos_laptop samsung_series_5_550 = {
         .i2c_peripherals = {
                 /* Touchpad. */
                 { .add = setup_cyapa_tp, I2C_ADAPTER_SMBUS },
@@ -330,14 +356,14 @@ static struct chromeos_laptop samsung_series_5_550 __initdata = {
         },
 };
 
-static struct chromeos_laptop samsung_series_5 __initdata = {
+static struct chromeos_laptop samsung_series_5 = {
         .i2c_peripherals = {
                 /* Light Sensor. */
                 { .add = setup_tsl2583_als, I2C_ADAPTER_SMBUS },
         },
 };
 
-static struct chromeos_laptop chromebook_pixel __initdata = {
+static struct chromeos_laptop chromebook_pixel = {
         .i2c_peripherals = {
                 /* Touch Screen. */
                 { .add = setup_atmel_1664s_ts, I2C_ADAPTER_PANEL },
@@ -348,28 +374,28 @@ static struct chromeos_laptop chromebook_pixel __initdata = {
         },
 };
 
-static struct chromeos_laptop acer_c7_chromebook __initdata = {
+static struct chromeos_laptop acer_c7_chromebook = {
         .i2c_peripherals = {
                 /* Touchpad. */
                 { .add = setup_cyapa_tp, I2C_ADAPTER_SMBUS },
         },
 };
 
-static struct chromeos_laptop acer_ac700 __initdata = {
+static struct chromeos_laptop acer_ac700 = {
         .i2c_peripherals = {
                 /* Light Sensor. */
                 { .add = setup_tsl2563_als, I2C_ADAPTER_SMBUS },
         },
 };
 
-static struct chromeos_laptop hp_pavilion_14_chromebook __initdata = {
+static struct chromeos_laptop hp_pavilion_14_chromebook = {
         .i2c_peripherals = {
                 /* Touchpad. */
                 { .add = setup_cyapa_tp, I2C_ADAPTER_SMBUS },
         },
 };
 
-static struct chromeos_laptop cr48 __initdata = {
+static struct chromeos_laptop cr48 = {
         .i2c_peripherals = {
                 /* Light Sensor. */
                 { .add = setup_tsl2563_als, I2C_ADAPTER_SMBUS },
@@ -377,7 +403,7 @@ static struct chromeos_laptop cr48 __initdata = {
 };
 
 #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 +462,45 @@ 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)