platform/chrome: chromeos_laptop - do not probe devices on Pixel 1

Atmel MXT devices use different i2c addresses, depending on the current mode of operation (bootloader or application). The new Atmel MXT driver expects i2c client's address contain the application address of the chip, and calculates the expected bootloader address form the application address. Unfortunately chromeos_laptop does probe the devices and if touchpad (or touchscreen, or both) comes up in bootloader mode, the i2c device gets instantiated with the bootloader address instead of application address, which confuses the driver.

Given that hardware on Pixel is set and is not going to change let's not try to probe devices to see if they are present or not, but rather instantiate them always at expected addresses.

Since all devices are now probed and/or instantiated at given address, we no longer need to support probing multiple addresses for the same

device.

Reviewed-by Benson Leung <[email protected]>

Signed-off-by Dmitry Torokhov <[email protected]>

---

Changes:

- v2 - addressed Bensons comments - removed Atmel bootloader addresses;

Olof,

We might want to mark this for stable as well as otherwise Pixel is pretty broken if either touchpad or touchscreen resets to bootloader mode.

Thanks,
Dmitry

 drivers/platform/chrome/chromeos_laptop.c | 72 ++++++-------------------------
 1 file changed, 13 insertions(+), 59 deletions(-)

drivers/platform/chrome/chromeos_laptop.c +13 -59

index b84fdd6..3dc258d 100644
@@ -30,9 +30,7 @@
 #include <linux/platform_device.h>
 
 #define ATMEL_TP_I2C_ADDR	0x4b
-#define ATMEL_TP_I2C_BL_ADDR	0x25
 #define ATMEL_TS_I2C_ADDR	0x4a
-#define ATMEL_TS_I2C_BL_ADDR	0x26
 #define CYAPA_TP_I2C_ADDR	0x67
 #define ISL_ALS_I2C_ADDR	0x44
 #define TAOS_ALS_I2C_ADDR	0x29

@@ -129,12 +127,12 @@ static struct i2c_board_info atmel_1664s_device = {
 	.flags		= I2C_CLIENT_WAKE,
 };
 
-static struct i2c_client *__add_probed_i2c_device(
-		const char *name,
-		int bus,
-		struct i2c_board_info *info,
-		const unsigned short *addrs)
+static struct i2c_client *add_i2c_device(const char *name,
+					 int bus,
+					 struct i2c_board_info *info,
+					 bool probe)
 {
+	const unsigned short addrs[] = { info->addr, I2C_CLIENT_END };
 	const struct dmi_device *dmi_dev;
 	const struct dmi_dev_onboard *dev_data;
 	struct i2c_adapter *adapter;

@@ -170,7 +168,8 @@ static struct i2c_client *__add_probed_i2c_device(
 	}
 
 	/* add the i2c device */
-	client = i2c_new_probed_device(adapter, info, addrs, NULL);
+	client = probe ? i2c_new_probed_device(adapter, info, addrs, NULL) :
+			 i2c_new_device(adapter, info);
 	if (!client)
 		pr_notice("%s failed to register device %d-%02x\n",
 			  __func__, bus, info->addr);

@@ -225,78 +224,33 @@ static int find_i2c_adapter_num(enum i2c_adapter_type type)
 	return adapter->nr;
 }
 
-/*
- * Takes a list of addresses in addrs as such :
- * { addr1, ... , addrn, I2C_CLIENT_END };
- * add_probed_i2c_device will use i2c_new_probed_device
- * and probe for devices at all of the addresses listed.
- * Returns NULL if no devices found.
- * See Documentation/i2c/instantiating-devices for more information.
- */
-static struct i2c_client *add_probed_i2c_device(
-		const char *name,
-		enum i2c_adapter_type type,
-		struct i2c_board_info *info,
-		const unsigned short *addrs)
-{
-	return __add_probed_i2c_device(name,
-				       find_i2c_adapter_num(type),
-				       info,
-				       addrs);
-}
-
-/*
- * Probes for a device at a single address, the one provided by
- * info->addr.
- * Returns NULL if no device found.
- */
-static struct i2c_client *add_i2c_device(const char *name,
-						enum i2c_adapter_type type,
-						struct i2c_board_info *info)
-{
-	const unsigned short addr_list[] = { info->addr, I2C_CLIENT_END };
-
-	return __add_probed_i2c_device(name,
-				       find_i2c_adapter_num(type),
-				       info,
-				       addr_list);
-}
-
 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);
+	tp = add_i2c_device("trackpad", type, &cyapa_device, true);
 	return (!tp) ? -EAGAIN : 0;
 }
 
 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);
+	tp = add_i2c_device("trackpad", type, &atmel_224s_tp_device, false);
 	return (!tp) ? -EAGAIN : 0;
 }
 
 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);
+	ts = add_i2c_device("touchscreen", type, &atmel_1664s_device, false);
 	return (!ts) ? -EAGAIN : 0;
 }
 

@@ -306,7 +260,7 @@ static int setup_isl29018_als(enum i2c_adapter_type type)
 		return 0;
 
 	/* add isl29018 light sensor */
-	als = add_i2c_device("lightsensor", type, &isl_als_device);
+	als = add_i2c_device("lightsensor", type, &isl_als_device, true);
 	return (!als) ? -EAGAIN : 0;
 }
 

@@ -316,7 +270,7 @@ static int setup_tsl2583_als(enum i2c_adapter_type type)
 		return 0;
 
 	/* add tsl2583 light sensor */
-	als = add_i2c_device(NULL, type, &tsl2583_als_device);
+	als = add_i2c_device(NULL, type, &tsl2583_als_device, true);
 	return (!als) ? -EAGAIN : 0;
 }
 

@@ -326,7 +280,7 @@ static int setup_tsl2563_als(enum i2c_adapter_type type)
 		return 0;
 
 	/* add tsl2563 light sensor */
-	als = add_i2c_device(NULL, type, &tsl2563_als_device);
+	als = add_i2c_device(NULL, type, &tsl2563_als_device, true);
 	return (!als) ? -EAGAIN : 0;
 }
 

Signature · 5 lines

2.2.0.rc0.207.ga3a616c


-- 
Dmitry

Quoted 13 lines · Dmitry Torokhov

Atmel MXT devices use different i2c addresses, depending on the current mode of operation (bootloader or application). The new Atmel MXT driver expects i2c client's address contain the application address of the chip, and calculates the expected bootloader address form the application address. Unfortunately chromeos_laptop does probe the devices and if touchpad (or touchscreen, or both) comes up in bootloader mode, the i2c device gets instantiated with the bootloader address instead of application address, which confuses the driver.

Given that hardware on Pixel is set and is not going to change let's not try to probe devices to see if they are present or not, but rather instantiate them always at expected addresses.

Quoted 2 lines

Since all devices are now probed and/or instantiated at given address, we no longer need to support probing multiple addresses for the same

Hmm, that strategy won't work on C720 since there are devices with touchscreen and without one, so we do want to probe but always instantiate at primary address. V3 will be upcoming...

From 480ea02024a0b9a2ad2f91e2e0ca02f34577972c Mon Sep 17 00:00:00 2001

Quoted 14 lines · Dmitry Torokhov

Quoted 13 lines · Dmitry Torokhov

Atmel MXT devices use different i2c addresses, depending on the current mode of operation (bootloader or application). The new Atmel MXT driver expects i2c client's address contain the application address of the chip, and calculates the expected bootloader address form the application address. Unfortunately chromeos_laptop does probe the devices and if touchpad (or touchscreen, or both) comes up in bootloader mode, the i2c device gets instantiated with the bootloader address instead of application address, which confuses the driver.

Given that hardware on Pixel is set and is not going to change let's not try to probe devices to see if they are present or not, but rather instantiate them always at expected addresses.

Quoted 6 lines

Quoted 2 lines

Since all devices are now probed and/or instantiated at given address, we no longer need to support probing multiple addresses for the same

Hmm, that strategy won't work on C720 since there are devices with touchscreen and without one, so we do want to probe but always instantiate at primary address. V3 will be upcoming...

OK, new version. Not sending to the wide world for now in case we decide

it is too ugly...

From 480ea02024a0b9a2ad2f91e2e0ca02f34577972c Mon Sep 17 00:00:00 2001
From: Dmitry Torokhov <[email protected]>
Date: Mon, 12 Jan 2015 13:59:32 -0800
Subject: [PATCH] platform/chrome: chromeos_laptop - instantiate Atmel at
primary address

The new Atmel MXT driver expects i2c client's address contain the primary (main address) of the chip, and calculates the expected bootloader address form the primary address. Unfortunately chrome_laptop does probe the devices and if touchpad (or touchscreen, or both) comes up in bootloader mode the i2c device gets instantiated with the bootloader address which confuses the driver.

To work around this issue let's probe the primary address first. If the device is not detected at the primary address we'll probe alternative addresses as "dummy" devices. If any of them are found, destroy the dummy client and instantiate client with proper name at primary address still.

Signed-off-by Dmitry Torokhov <[email protected]>

---
 drivers/platform/chrome/chromeos_laptop.c | 35 +++++++++++++++++++++++--------
 1 file changed, 26 insertions(+), 9 deletions(-)

drivers/platform/chrome/chromeos_laptop.c +26 -9

index b84fdd6..a04019a 100644
@@ -133,12 +133,13 @@ static struct i2c_client *__add_probed_i2c_device(
 		const char *name,
 		int bus,
 		struct i2c_board_info *info,
-		const unsigned short *addrs)
+		const unsigned short *alt_addr_list)
 {
 	const struct dmi_device *dmi_dev;
 	const struct dmi_dev_onboard *dev_data;
 	struct i2c_adapter *adapter;
-	struct i2c_client *client;
+	struct i2c_client *client = NULL;
+	const unsigned short addr_list[] = { info->addr, I2C_CLIENT_END };
 
 	if (bus < 0)
 		return NULL;

@@ -169,8 +170,28 @@ static struct i2c_client *__add_probed_i2c_device(
 		return NULL;
 	}
 
-	/* add the i2c device */
-	client = i2c_new_probed_device(adapter, info, addrs, NULL);
+	/*
+	 * Add the i2c device. If we can't detect it at the primary
+	 * address we scan secondary addresses. In any case the client
+	 * structure gets assigned primary address.
+	 */
+	client = i2c_new_probed_device(adapter, info, addr_list, NULL);
+	if (!client && alt_addr_list) {
+		struct i2c_board_info dummy_info = {
+			I2C_BOARD_INFO("dummy", info->addr),
+		};
+		struct i2c_client *dummy;
+
+		dummy = i2c_new_probed_device(adapter, &dummy_info,
+					      alt_addr_list, NULL);
+		if (dummy) {
+			pr_debug("%s %d-%02x is probed at %02x\n",
+				  __func__, bus, info->addr, dummy->addr);
+			i2c_unregister_device(dummy);
+			client = i2c_new_device(adapter, info);
+		}
+	}
+
 	if (!client)
 		pr_notice("%s failed to register device %d-%02x\n",
 			  __func__, bus, info->addr);

@@ -254,12 +275,10 @@ static struct i2c_client *add_i2c_device(const char *name,
 						enum i2c_adapter_type type,
 						struct i2c_board_info *info)
 {
-	const unsigned short addr_list[] = { info->addr, I2C_CLIENT_END };
-
 	return __add_probed_i2c_device(name,
 				       find_i2c_adapter_num(type),
 				       info,
-				       addr_list);
+				       NULL);
 }
 
 static int setup_cyapa_tp(enum i2c_adapter_type type)

@@ -275,7 +294,6 @@ static int setup_cyapa_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;

@@ -289,7 +307,6 @@ static int setup_atmel_224s_tp(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;

Signature · 5 lines

2.2.0.rc0.207.ga3a616c


-- 
Dmitry

Quoted 17 lines · Dmitry Torokhov

Quoted 15 lines · Dmitry Torokhov

Atmel MXT devices use different i2c addresses, depending on the current mode of operation (bootloader or application). The new Atmel MXT driver expects i2c client's address contain the application address of the chip, and calculates the expected bootloader address form the application address. Unfortunately chromeos_laptop does probe the devices and if touchpad (or touchscreen, or both) comes up in bootloader mode, the i2c device gets instantiated with the bootloader address instead of application address, which confuses the driver.

Given that hardware on Pixel is set and is not going to change let's not try to probe devices to see if they are present or not, but rather instantiate them always at expected addresses.

Since all devices are now probed and/or instantiated at given address, we no longer need to support probing multiple addresses for the same

Quoted 3 lines

Hmm, that strategy won't work on C720 since there are devices with touchscreen and without one, so we do want to probe but always instantiate at primary address. V3 will be upcoming...

OK, new version. Not sending to the wide world for now in case we decide it is too ugly...