From 48e9743dd6483c5fd3f10c8e42c60d52d64b0e27 Mon Sep 17 00:00:00 2001 From: Vladimir Zapolskiy Date: Mon, 27 Jul 2015 17:30:50 +0300 Subject: i2c: core: add and export of_get_i2c_adapter_by_node() interface of_find_i2c_adapter_by_node() call requires quite often missing put_device(), and i2c_put_adapter() releases a device locked by i2c_get_adapter() only. In general module_put(adapter->owner) and put_device(dev) are not interchangeable. This is a common error reproduction scenario as a result of the misusage described above (for clearness this is run on iMX6 platform with HDMI and I2C bus drivers compiled as kernel modules): root@mx6q:~# lsmod | grep i2c i2c_imx 10213 0 root@mx6q:~# lsmod | grep dw_hdmi_imx dw_hdmi_imx 3631 0 dw_hdmi 11846 1 dw_hdmi_imx imxdrm 8674 3 dw_hdmi_imx,imx_ipuv3_crtc,imx_ldb drm_kms_helper 113765 5 dw_hdmi,imxdrm,imx_ipuv3_crtc,imx_ldb root@mx6q:~# rmmod dw_hdmi_imx root@mx6q:~# lsmod | grep i2c i2c_imx 10213 -1 ^^^^^ root@mx6q:~# rmmod i2c_imx rmmod: ERROR: Module i2c_imx is in use To fix existing users of these interfaces and to avoid any further confusion and misusage in future, add one more interface of_get_i2c_adapter_by_node(), it is similar to i2c_get_adapter() in sense that an I2C bus device driver found and locked by user can be correctly unlocked by i2c_put_adapter(). Signed-off-by: Vladimir Zapolskiy Signed-off-by: Wolfram Sang --- include/linux/i2c.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux') diff --git a/include/linux/i2c.h b/include/linux/i2c.h index e83a738a3b87..e2c859b74f8b 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -638,6 +638,8 @@ extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node); /* must call put_device() when done with returned i2c_adapter device */ extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node); +/* must call i2c_put_adapter() when done with returned i2c_adapter device */ +struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node); #else static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) @@ -649,6 +651,11 @@ static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node { return NULL; } + +static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) +{ + return NULL; +} #endif /* CONFIG_OF */ #endif /* _LINUX_I2C_H */ -- cgit v1.2.3 From c5ebb387f4e6b2dd7c74d71caf7b696834d0c887 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Tue, 19 May 2015 17:44:31 +0200 Subject: i2c: add a flag to mark clients as slaves And update indentation with one more tab, sigh... Tested-by: Andrey Danin Acked-by: Stephen Warren Signed-off-by: Wolfram Sang Signed-off-by: Wolfram Sang --- include/linux/i2c.h | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/include/linux/i2c.h b/include/linux/i2c.h index e2c859b74f8b..5aea07137218 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -550,11 +550,12 @@ void i2c_lock_adapter(struct i2c_adapter *); void i2c_unlock_adapter(struct i2c_adapter *); /*flags for the client struct: */ -#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ -#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ +#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ +#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ /* Must equal I2C_M_TEN below */ -#define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ -#define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ +#define I2C_CLIENT_SLAVE 0x20 /* we are the slave */ +#define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ +#define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ /* Must match I2C_M_STOP|IGNORE_NAK */ /* i2c adapter classes (bitmask) */ -- cgit v1.2.3 From b3fdd32799d834e2626fae087906e886037350c6 Mon Sep 17 00:00:00 2001 From: York Sun Date: Mon, 17 Aug 2015 11:53:48 -0700 Subject: i2c: mux: Add register-based mux i2c-mux-reg Based on i2c-mux-gpio driver, similarly the register-based mux switch from one bus to another by setting a single register. The register can be on PCIe bus, local bus, or any memory-mapped address. The endianness of such register can be specified in device tree if used, or in platform data. Signed-off-by: York Sun Acked-by: Alexander Sverdlin Signed-off-by: Wolfram Sang --- include/linux/platform_data/i2c-mux-reg.h | 44 +++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 include/linux/platform_data/i2c-mux-reg.h (limited to 'include/linux') diff --git a/include/linux/platform_data/i2c-mux-reg.h b/include/linux/platform_data/i2c-mux-reg.h new file mode 100644 index 000000000000..c68712aadf43 --- /dev/null +++ b/include/linux/platform_data/i2c-mux-reg.h @@ -0,0 +1,44 @@ +/* + * I2C multiplexer using a single register + * + * Copyright 2015 Freescale Semiconductor + * York Sun + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#ifndef __LINUX_PLATFORM_DATA_I2C_MUX_REG_H +#define __LINUX_PLATFORM_DATA_I2C_MUX_REG_H + +/** + * struct i2c_mux_reg_platform_data - Platform-dependent data for i2c-mux-reg + * @parent: Parent I2C bus adapter number + * @base_nr: Base I2C bus number to number adapters from or zero for dynamic + * @values: Array of value for each channel + * @n_values: Number of multiplexer channels + * @little_endian: Indicating if the register is in little endian + * @write_only: Reading the register is not allowed by hardware + * @classes: Optional I2C auto-detection classes + * @idle: Value to write to mux when idle + * @idle_in_use: indicate if idle value is in use + * @reg: Virtual address of the register to switch channel + * @reg_size: register size in bytes + */ +struct i2c_mux_reg_platform_data { + int parent; + int base_nr; + const unsigned int *values; + int n_values; + bool little_endian; + bool write_only; + const unsigned int *classes; + u32 idle; + bool idle_in_use; + void __iomem *reg; + resource_size_t reg_size; +}; + +#endif /* __LINUX_PLATFORM_DATA_I2C_MUX_REG_H */ -- cgit v1.2.3 From 01eef96e37d77cd89156e5f51aab81a9d5c96539 Mon Sep 17 00:00:00 2001 From: Irina Tirdea Date: Wed, 12 Aug 2015 17:31:33 +0300 Subject: i2c: core: Add support for best effort block read emulation There are devices that need to handle block transactions regardless of the capabilities exported by the adapter. For performance reasons, they need to use i2c read blocks if available, otherwise emulate the block transaction with word or byte transactions. Add support for a helper function that would read a data block using the best transfer available: I2C_FUNC_SMBUS_READ_I2C_BLOCK, I2C_FUNC_SMBUS_READ_WORD_DATA or I2C_FUNC_SMBUS_READ_BYTE_DATA. Signed-off-by: Irina Tirdea Signed-off-by: Wolfram Sang --- include/linux/i2c.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux') diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 5aea07137218..768063baafbf 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -121,6 +121,9 @@ extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command, u8 length, const u8 *values); +extern s32 +i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, + u8 command, u8 length, u8 *values); #endif /* I2C */ /** -- cgit v1.2.3