Add support for the I2C bus functionality of the TI SM-USB-DIG. Signed-off-by: Andrew F. Davis <afd@xxxxxx> --- drivers/i2c/busses/Kconfig | 10 ++ drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-sm-usb-dig.c | 190 ++++++++++++++++++++++++++++++++++++ 3 files changed, 201 insertions(+) create mode 100644 drivers/i2c/busses/i2c-sm-usb-dig.c diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index f167021..5c74d09 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -1076,6 +1076,16 @@ config I2C_ROBOTFUZZ_OSIF This driver can also be built as a module. If so, the module will be called i2c-osif. +config I2C_SM_USB_DIG + tristate "Texas Instruments SM-USB-DIG I2C interface" + depends on MFD_SM_USB_DIG + help + This adds support for the I2C bus functionality of the + TI SM-USB-DIG USB interface adapter. + + This driver can also be built as a module. If so, the module + will be called i2c-sm-usb-dig. + config I2C_TAOS_EVM tristate "TAOS evaluation module" depends on TTY diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 37f2819..2ee25ef 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -103,6 +103,7 @@ obj-$(CONFIG_I2C_DLN2) += i2c-dln2.o obj-$(CONFIG_I2C_PARPORT) += i2c-parport.o obj-$(CONFIG_I2C_PARPORT_LIGHT) += i2c-parport-light.o obj-$(CONFIG_I2C_ROBOTFUZZ_OSIF) += i2c-robotfuzz-osif.o +obj-$(CONFIG_I2C_SM_USB_DIG) += i2c-sm-usb-dig.o obj-$(CONFIG_I2C_TAOS_EVM) += i2c-taos-evm.o obj-$(CONFIG_I2C_TINY_USB) += i2c-tiny-usb.o obj-$(CONFIG_I2C_VIPERBOARD) += i2c-viperboard.o diff --git a/drivers/i2c/busses/i2c-sm-usb-dig.c b/drivers/i2c/busses/i2c-sm-usb-dig.c new file mode 100644 index 0000000..719a8c1 --- /dev/null +++ b/drivers/i2c/busses/i2c-sm-usb-dig.c @@ -0,0 +1,190 @@ +/* + * I2C bus driver for TI SM-USB-DIG + * + * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/ + * Andrew F. Davis <afd@xxxxxx> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether expressed or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License version 2 for more details. + */ + +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/platform_device.h> + +#include <linux/mfd/sm-usb-dig.h> + +/* (data size - start condition - address - ACK) / ACK after data byte */ +#define SMUSBDIG_I2C_MAX_MSG ((SMUSBDIG_DATA_SIZE - 3) / 2) + +struct smusbdig_i2c { + struct device *dev; + struct smusbdig_device *smusbdig; + struct i2c_adapter adapter; +}; + +enum smusbdig_i2c_command { + SMUSBDIG_I2C_START = 0x3, + SMUSBDIG_I2C_STOP = 0x4, + SMUSBDIG_I2C_ACKM = 0x5, + SMUSBDIG_I2C_ACKS = 0x6, +}; + +static void smusbdig_i2c_packet_init(struct smusbdig_packet *packet) +{ + memset(packet, 0, sizeof(*packet)); + packet->function = SMUSBDIG_I2C; + packet->channel = 0x1; +} + +static int smusbdig_i2c_xfer(struct i2c_adapter *adapter, + struct i2c_msg *msgs, int num) +{ + struct smusbdig_i2c *smusbdig_i2c = i2c_get_adapdata(adapter); + struct smusbdig_packet packet; + int i, j, k, ret; + + for (i = 0; i < num; i++) { + smusbdig_i2c_packet_init(&packet); + smusbdig_packet_add_command(&packet, SMUSBDIG_I2C_START); + /* add read bit to address if needed */ + msgs[i].addr <<= 1; + if (msgs[i].flags & I2C_M_RD) + msgs[i].addr |= BIT(0); + smusbdig_packet_add_data(&packet, msgs[i].addr); + smusbdig_packet_add_command(&packet, SMUSBDIG_I2C_ACKS); + if (msgs[i].flags & I2C_M_RD) { + for (j = 0; j < msgs[i].len; j++) { + smusbdig_packet_add_data(&packet, 0xff); + smusbdig_packet_add_command(&packet, SMUSBDIG_I2C_ACKM); + } + } else { + for (j = 0; j < msgs[i].len; j++) { + smusbdig_packet_add_data(&packet, msgs[i].buf[j]); + smusbdig_packet_add_command(&packet, SMUSBDIG_I2C_ACKS); + } + } + + ret = smusbdig_xfer(smusbdig_i2c->smusbdig, + (u8 *)&packet, sizeof(packet)); + if (ret) + return ret; + + /* + * now we read in any data we got during read MSGs + * and check ACKS + */ + if (((u8 *)&packet)[2]) { + num = -EPROTO; + goto stop; + } + for (j = 0, k = 3; j < msgs[i].len; j++, k += 2) { + if (msgs[i].flags & I2C_M_RD) { + msgs[i].buf[j] = ((u8 *)&packet)[k]; + } else if (((u8 *)&packet)[k + 1]) { + num = -EPROTO; + goto stop; + } + } + } + +stop: + /* send stop condition */ + smusbdig_i2c_packet_init(&packet); + smusbdig_packet_add_command(&packet, SMUSBDIG_I2C_STOP); + ret = smusbdig_xfer(smusbdig_i2c->smusbdig, + (u8 *)&packet, sizeof(packet)); + if (ret) + return ret; + + return num; +} + +static u32 smusbdig_i2c_func(struct i2c_adapter *adapter) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static const struct i2c_algorithm smusbdig_i2c_algo = { + .master_xfer = smusbdig_i2c_xfer, + .functionality = smusbdig_i2c_func, +}; + +static struct i2c_adapter smusbdig_i2c_adapter = { + .owner = THIS_MODULE, + .class = I2C_CLASS_HWMON, + .algo = &smusbdig_i2c_algo, +}; + +static struct i2c_adapter_quirks dln2_i2c_quirks = { + .max_read_len = SMUSBDIG_I2C_MAX_MSG, + .max_write_len = SMUSBDIG_I2C_MAX_MSG, +}; + +static int smusbdig_i2c_probe(struct platform_device *pdev) +{ + struct smusbdig_i2c *smusbdig_i2c; + struct device *dev = &pdev->dev; + int ret; + + smusbdig_i2c = devm_kzalloc(dev, sizeof(*smusbdig_i2c), GFP_KERNEL); + if (!smusbdig_i2c) + return -ENOMEM; + + smusbdig_i2c->dev = dev; + smusbdig_i2c->smusbdig = dev_get_drvdata(dev->parent); + smusbdig_i2c->adapter = smusbdig_i2c_adapter; + strlcpy(smusbdig_i2c->adapter.name, dev_name(dev), + sizeof(smusbdig_i2c->adapter.name)); + smusbdig_i2c->adapter.quirks = &dln2_i2c_quirks; + smusbdig_i2c->adapter.dev.parent = dev; + smusbdig_i2c->adapter.dev.of_node = dev->of_node; + + i2c_set_adapdata(&smusbdig_i2c->adapter, smusbdig_i2c); + platform_set_drvdata(pdev, smusbdig_i2c); + + ret = i2c_add_adapter(&smusbdig_i2c->adapter); + if (ret) { + dev_err(dev, "unable to add I2C adapter\n"); + return ret; + } + + dev_info(dev, "TI SM-USB-DIG Added: I2C Bus\n"); + + return 0; +} + +static int smusbdig_i2c_remove(struct platform_device *pdev) +{ + struct smusbdig_i2c *smusbdig_i2c = platform_get_drvdata(pdev); + + i2c_del_adapter(&smusbdig_i2c->adapter); + + return 0; +} + +static const struct platform_device_id smusbdig_i2c_id_table[] = { + { "sm-usb-dig-i2c", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(platform, smusbdig_i2c_id_table); + +static struct platform_driver smusbdig_i2c_driver = { + .driver = { + .name = "sm-usb-dig-i2c", + }, + .probe = smusbdig_i2c_probe, + .remove = smusbdig_i2c_remove, + .id_table = smusbdig_i2c_id_table, +}; +module_platform_driver(smusbdig_i2c_driver); + +MODULE_AUTHOR("Andrew F. Davis <afd@xxxxxx>"); +MODULE_DESCRIPTION("I2C bus driver for TI SM-USB-DIG interface adapter"); +MODULE_LICENSE("GPL v2"); -- 2.8.3 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
