Add support for the I2C bus functionality of the TI SM-USB-DIG.
Signed-off-by: Andrew F. Davis <[email protected]>
---
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 <[email protected]>
+ *
+ * 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 <[email protected]>");
+MODULE_DESCRIPTION("I2C bus driver for TI SM-USB-DIG interface adapter");
+MODULE_LICENSE("GPL v2");
--
2.8.3
