Adds support for USB-I2C interface of Cypress Semiconductor CYUSBS234 USB-Serial Bridge controller. The read/write operation is setup using vendor command through control endpoint and actual data transfer happens through bulk in/out endpoints. Details about the device can be found at: http://www.cypress.com/?rID=84126 Signed-off-by: Muthu Mani <muth@xxxxxxxxxxx> Signed-off-by: Rajaram Regupathy <rera@xxxxxxxxxxx> --- drivers/i2c/busses/Kconfig | 12 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-cyusbs23x.c | 514 +++++++++++++++++++++++++++++++++++++ 3 files changed, 527 insertions(+) create mode 100644 drivers/i2c/busses/i2c-cyusbs23x.c diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 2ac87fa..1fdc6ec 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -848,6 +848,18 @@ config I2C_RCAR comment "External I2C/SMBus adapter drivers" +config I2C_CYUSBS23X + tristate "CYUSBS23x I2C adapter" + depends on MFD_CYUSBS23X && USB + help + Say yes if you would like to access Cypress CYUSBS23x I2C device. + + This driver enables the I2C interface of CYUSBS23x USB Serial Bridge + controller. + + This driver can also be built as a module. If so, the module will be + called i2c-cyusbs23x. + config I2C_DIOLAN_U2C tristate "Diolan U2C-12 USB adapter" depends on USB diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 49bf07e..cbf28cb 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -84,6 +84,7 @@ obj-$(CONFIG_I2C_XLR) += i2c-xlr.o obj-$(CONFIG_I2C_RCAR) += i2c-rcar.o # External I2C/SMBus adapter drivers +obj-$(CONFIG_I2C_CYUSBS23X) += i2c-cyusbs23x.o obj-$(CONFIG_I2C_DIOLAN_U2C) += i2c-diolan-u2c.o obj-$(CONFIG_I2C_PARPORT) += i2c-parport.o obj-$(CONFIG_I2C_PARPORT_LIGHT) += i2c-parport-light.o diff --git a/drivers/i2c/busses/i2c-cyusbs23x.c b/drivers/i2c/busses/i2c-cyusbs23x.c new file mode 100644 index 0000000..5cf60f0 --- /dev/null +++ b/drivers/i2c/busses/i2c-cyusbs23x.c @@ -0,0 +1,514 @@ +/* + * I2C subdriver for Cypress CYUSBS234 USB-Serial Bridge controller. + * Details about the device can be found at: + * http://www.cypress.com/?rID=84126 + * + * Copyright (c) 2014 Cypress Semiconductor Corporation. + * + * Author: + * Rajaram Regupathy <rera@xxxxxxxxxxx> + * + * Additional contributors include: + * Muthu Mani <muth@xxxxxxxxxxx> + * + * 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. + */ + +/* + * It exposes sysfs entries under the i2c adapter for getting the i2c transfer + * status, reset i2c read/write module, get/set nak and stop bits. + */ + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/mutex.h> +#include <linux/platform_device.h> + +#include <linux/usb.h> +#include <linux/i2c.h> + +#include <linux/mfd/cyusbs23x.h> + +#define CY_I2C_MODE_WRITE 1 +#define CY_I2C_MODE_READ 0 + +#define CY_I2C_XFER_STATUS_LEN 3 + +struct cyusbs_i2c_config { + u32 frequency; /* Frequency of operation. Only valid values are + 100KHz and 400KHz */ + u8 slave_addr; /* Slave address to be used when in slave mode */ + u8 is_msb_first; /* Whether to transmit MSB first */ + u8 is_master; /* Whether block is to be configured as a master: + 1 - The block functions as I2C master; + 0 - The block functions as I2C slave */ + u8 s_ignore; /* Ignore general call in slave mode */ + u8 clock_stretch; /* Whether to stretch clock in case of no FIFO + availability */ + u8 is_loopback; /* Whether to loop back TX data to RX. Valid + only for debug purposes */ + u8 reserved[6]; /* Reserved for future use */ +} __packed; + +struct cyusbs_i2c { + struct i2c_adapter i2c_adapter; + struct cyusbs_i2c_config *i2c_config; + + bool is_stop_bit; + bool is_nak_bit; +}; + +#define to_cyusbs_i2c(a) container_of(a, struct cyusbs_i2c, i2c_adapter) + +static int cy_i2c_get_status(struct device *d, char *buf, u16 mode); +static int cy_i2c_reset(struct device *d, u16 mode); + +static ssize_t i2c_read_status_show(struct device *d, + struct device_attribute *attr, char *buf) +{ + dev_dbg(d, "%s\n", __func__); + return cy_i2c_get_status(d, buf, CY_I2C_MODE_READ); +} + +static ssize_t i2c_write_status_show(struct device *d, + struct device_attribute *attr, char *buf) +{ + dev_dbg(d, "%s\n", __func__); + return cy_i2c_get_status(d, buf, CY_I2C_MODE_WRITE); +} + +static ssize_t i2c_read_reset_store(struct device *d, + struct device_attribute *attr, + const char *buf, size_t count) +{ + int ret; + + if (((count != 1) && (count != 2 || buf[1] != '\n')) || (buf[0] != '1')) + return -EINVAL; + + dev_dbg(d, "%s\n", __func__); + ret = cy_i2c_reset(d, CY_I2C_MODE_READ); + + if (!ret) + ret = count; + + return ret; +} + +static ssize_t i2c_write_reset_store(struct device *d, + struct device_attribute *attr, + const char *buf, size_t count) +{ + int ret; + + if (((count != 1) && (count != 2 || buf[1] != '\n')) || (buf[0] != '1')) + return -EINVAL; + + dev_dbg(d, "%s\n", __func__); + ret = cy_i2c_reset(d, CY_I2C_MODE_WRITE); + + if (!ret) + ret = count; + + return ret; +} + +static ssize_t is_stop_bit_show(struct device *d, + struct device_attribute *attr, char *buf) +{ + struct i2c_adapter *adapter = to_i2c_adapter(d); + struct cyusbs_i2c *cy_i2c = to_cyusbs_i2c(adapter); + + return sprintf(buf, "%d\n", cy_i2c->is_stop_bit); +} + +static ssize_t is_stop_bit_store(struct device *d, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct i2c_adapter *adapter = to_i2c_adapter(d); + struct cyusbs_i2c *cy_i2c = to_cyusbs_i2c(adapter); + + if ((count != 1) && (count != 2 || buf[1] != '\n')) + return -EINVAL; + + if (buf[0] == '0') + cy_i2c->is_stop_bit = 0; + else if (buf[0] == '1') + cy_i2c->is_stop_bit = 1; + else + return -EINVAL; + + dev_dbg(d, "is_stop_bit=%d buf=%s\n", cy_i2c->is_stop_bit, buf); + + return count; +} + +static ssize_t is_nak_bit_show(struct device *d, + struct device_attribute *attr, char *buf) +{ + struct i2c_adapter *adapter = to_i2c_adapter(d); + struct cyusbs_i2c *cy_i2c = to_cyusbs_i2c(adapter); + + return sprintf(buf, "%d\n", cy_i2c->is_nak_bit); +} + +static ssize_t is_nak_bit_store(struct device *d, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct i2c_adapter *adapter = to_i2c_adapter(d); + struct cyusbs_i2c *cy_i2c = to_cyusbs_i2c(adapter); + + if ((count != 1) && (count != 2 || buf[1] != '\n')) + return -EINVAL; + + if (buf[0] == '0') + cy_i2c->is_nak_bit = 0; + else if (buf[0] == '1') + cy_i2c->is_nak_bit = 1; + else + return -EINVAL; + + dev_dbg(d, "is_nak_bit=%d buf=%s\n", cy_i2c->is_nak_bit, buf); + + return count; +} + +static DEVICE_ATTR_RO(i2c_read_status); +static DEVICE_ATTR_RO(i2c_write_status); +static DEVICE_ATTR_WO(i2c_read_reset); +static DEVICE_ATTR_WO(i2c_write_reset); +static DEVICE_ATTR_RW(is_stop_bit); +static DEVICE_ATTR_RW(is_nak_bit); + +static struct attribute *cyusbs_i2c_device_attrs[] = { + &dev_attr_i2c_read_status.attr, + &dev_attr_i2c_write_status.attr, + &dev_attr_i2c_read_reset.attr, + &dev_attr_i2c_write_reset.attr, + &dev_attr_is_stop_bit.attr, + &dev_attr_is_nak_bit.attr, + NULL +}; + +ATTRIBUTE_GROUPS(cyusbs_i2c_device); + +static int cy_i2c_get_status(struct device *d, char *buf, u16 mode) +{ + int ret; + u16 wIndex, wValue, scb_index; + struct i2c_adapter *adapter = to_i2c_adapter(d); + struct cyusbs23x *cyusbs = (struct cyusbs23x *)adapter->algo_data; + char *data; + + scb_index = cyusbs->intf_num & 0x01; + wValue = ((scb_index << CY_SCB_INDEX_POS) | mode); + wIndex = 0; + data = kmalloc(CY_I2C_XFER_STATUS_LEN, GFP_KERNEL); + + mutex_lock(&cyusbs->lock); + /* read the i2c transfer status */ + ret = usb_control_msg(cyusbs->usb_dev, + usb_rcvctrlpipe(cyusbs->usb_dev, 0), + CY_I2C_GET_STATUS_CMD, + USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN, + wValue, wIndex, data, CY_I2C_XFER_STATUS_LEN, 2000); + mutex_unlock(&cyusbs->lock); + + memcpy(buf, data, CY_I2C_XFER_STATUS_LEN); + kfree(data); + + dev_dbg(&cyusbs->usb_intf->dev, "%s: %02x %02x %02x\n", __func__, + buf[0], buf[1], buf[2]); + return ret; +} + +static int cy_i2c_reset(struct device *d, u16 mode) +{ + int ret; + u16 wIndex, wValue, scb_index; + struct i2c_adapter *adapter = to_i2c_adapter(d); + struct cyusbs23x *cyusbs = (struct cyusbs23x *)adapter->algo_data; + + scb_index = cyusbs->intf_num & 0x01; + wValue = ((scb_index << CY_SCB_INDEX_POS) | mode); + wIndex = 0; + + mutex_lock(&cyusbs->lock); + ret = usb_control_msg(cyusbs->usb_dev, + usb_sndctrlpipe(cyusbs->usb_dev, 0), + CY_I2C_RESET_CMD, + USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT, + wValue, wIndex, NULL, 0, 2000); + mutex_unlock(&cyusbs->lock); + dev_dbg(d, "%s: %d\n", __func__, ret); + return ret; +} + +static int cy_get_i2c_config(struct cyusbs23x *cyusbs, + struct cyusbs_i2c *cy_i2c) +{ + int ret; + u16 scb_index; + + dev_dbg(&cyusbs->usb_intf->dev, "%s\n", __func__); + + scb_index = (cyusbs->intf_num & 0x01) << CY_SCB_INDEX_POS; + + mutex_lock(&cyusbs->lock); + ret = usb_control_msg(cyusbs->usb_dev, + usb_rcvctrlpipe(cyusbs->usb_dev, 0), + CY_I2C_GET_CONFIG_CMD, + USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN, + scb_index, 0, cy_i2c->i2c_config, + sizeof(*cy_i2c->i2c_config), 2000); + mutex_unlock(&cyusbs->lock); + + dev_dbg(&cyusbs->usb_intf->dev, "%s: %d, 0x%02x, %d, %d, %d, %d, %d\n", + __func__, cy_i2c->i2c_config->frequency, + cy_i2c->i2c_config->slave_addr, + cy_i2c->i2c_config->is_msb_first, + cy_i2c->i2c_config->is_master, + cy_i2c->i2c_config->s_ignore, + cy_i2c->i2c_config->clock_stretch, + cy_i2c->i2c_config->is_loopback); + return ret; +} + +static int cy_i2c_set_data_config(struct cyusbs23x *cyusbs, + struct cyusbs_i2c *cy_i2c, u16 slave_addr, + u16 length, u8 command) +{ + int ret; + u16 wIndex, wValue; + u16 scb_index; + + dev_dbg(&cyusbs->usb_intf->dev, "%s\n", __func__); + + scb_index = (cyusbs->intf_num & 0x01) << 7; + slave_addr = (slave_addr & 0x7F) | scb_index; + wValue = cy_i2c->is_stop_bit | cy_i2c->is_nak_bit << 1; + wValue |= (slave_addr << 8); + wIndex = length; + + dev_dbg(&cyusbs->usb_intf->dev, + "%s, cmd=0x%x,val=0x%x,idx=0x%x\n", + __func__, command, wValue, wIndex); + + ret = usb_control_msg(cyusbs->usb_dev, + usb_sndctrlpipe(cyusbs->usb_dev, 0), + command, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT, + wValue, wIndex, NULL, 0, 2000); + + return ret; +} + +static int cy_i2c_read(struct cyusbs23x *cyusbs, struct i2c_msg *msgs) +{ + int ret, actual_read_len = 0; + + dev_dbg(&cyusbs->usb_intf->dev, "%s\n", __func__); + + ret = usb_bulk_msg(cyusbs->usb_dev, + usb_rcvbulkpipe(cyusbs->usb_dev, cyusbs->bulk_in_ep_num), + msgs[0].buf, + msgs[0].len, + &actual_read_len, 5000); + + if (ret) + dev_dbg(&cyusbs->usb_intf->dev, + "read %d/%d returned %d\n", + actual_read_len, msgs[0].len, ret); + + return ret; +} + +static int cy_i2c_write(struct cyusbs23x *cyusbs, struct i2c_msg *msgs) +{ + int ret, actual_write_len = 0; + + dev_dbg(&cyusbs->usb_intf->dev, "%s\n", __func__); + + ret = usb_bulk_msg(cyusbs->usb_dev, + usb_sndbulkpipe(cyusbs->usb_dev, cyusbs->bulk_out_ep_num), + msgs[0].buf, + msgs[0].len, + &actual_write_len, 5000); + + if (ret) + dev_dbg(&cyusbs->usb_intf->dev, + "write %d/%d returned %d\n", + actual_write_len, msgs[0].len, ret); + + return ret; +} + +static int cy_i2c_xfer(struct i2c_adapter *adapter, + struct i2c_msg *msgs, int num) +{ + int ret = 0; + struct cyusbs_i2c *cy_i2c; + struct cyusbs23x *cyusbs = (struct cyusbs23x *)adapter->algo_data; + + dev_dbg(&adapter->dev, "%s\n", __func__); + + if (num > 1) { + dev_err(&adapter->dev, "i2c_msg number is > 1\n"); + return -EIO; + } + + cy_i2c = to_cyusbs_i2c(adapter); + + mutex_lock(&cyusbs->lock); + if (msgs[0].flags & I2C_M_RD) { + dev_dbg(&adapter->dev, + "I2C read requested for addr 0x%02x, data length %d\n", + msgs[0].addr, msgs[0].len); + + ret = cy_i2c_set_data_config(cyusbs, cy_i2c, msgs[0].addr, + msgs[0].len, CY_I2C_READ_CMD); + + if (ret < 0) { + dev_err(&adapter->dev, + "Set Config (read) failed with %d\n", ret); + goto io_error; + } + + ret = cy_i2c_read(cyusbs, msgs); + if (ret) { + dev_err(&adapter->dev, + "Read failed with error code %d\n", ret); + goto io_error; + } + } else { + dev_dbg(&adapter->dev, + "I2C write requested for addr 0x%02x, data length %d\n", + msgs[0].addr, msgs[0].len); + + ret = cy_i2c_set_data_config(cyusbs, cy_i2c, msgs[0].addr, + msgs[0].len, CY_I2C_WRITE_CMD); + + if (ret < 0) { + dev_err(&adapter->dev, + "Set Config (write) failed with %d\n", ret); + goto io_error; + } + + ret = cy_i2c_write(cyusbs, msgs); + if (ret) { + dev_err(&adapter->dev, + "Write failed with error code %d\n", ret); + goto io_error; + } + } + mutex_unlock(&cyusbs->lock); + return ret; + +io_error: + mutex_unlock(&cyusbs->lock); + return ret; +} + +static u32 cy_i2c_func(struct i2c_adapter *adapter) +{ + dev_dbg(&adapter->dev, "%s\n", __func__); + return I2C_FUNC_I2C; +} + +static const struct i2c_algorithm i2c_cyusbs23x_algorithm = { + .master_xfer = cy_i2c_xfer, + .functionality = cy_i2c_func, +}; + +static int cyusbs23x_i2c_probe(struct platform_device *pdev) +{ + struct cyusbs23x *cyusbs; + struct cyusbs_i2c *cy_i2c; + int ret = 0; + + dev_dbg(&pdev->dev, "%s\n", __func__); + + cyusbs = dev_get_drvdata(pdev->dev.parent); + + cy_i2c = devm_kzalloc(&pdev->dev, sizeof(*cy_i2c), GFP_KERNEL); + if (cy_i2c == NULL) + return -ENOMEM; + + cy_i2c->i2c_config = kmalloc(sizeof(struct cyusbs_i2c_config), + GFP_KERNEL); + if (cy_i2c->i2c_config == NULL) + return -ENOMEM; + + cy_i2c->is_stop_bit = 1; + cy_i2c->is_nak_bit = 1; + + cy_i2c->i2c_adapter.owner = THIS_MODULE; + cy_i2c->i2c_adapter.class = I2C_CLASS_HWMON; + cy_i2c->i2c_adapter.algo = &i2c_cyusbs23x_algorithm; + cy_i2c->i2c_adapter.algo_data = cyusbs; + snprintf(cy_i2c->i2c_adapter.name, sizeof(cy_i2c->i2c_adapter.name), + "cyusbs23x_i2c at bus %03d dev %03d intf %03d", + cyusbs->usb_dev->bus->busnum, cyusbs->usb_dev->devnum, + cyusbs->intf_num); + cy_i2c->i2c_adapter.dev.parent = &pdev->dev; + cy_i2c->i2c_adapter.dev.groups = cyusbs_i2c_device_groups; + + ret = cy_get_i2c_config(cyusbs, cy_i2c); + if (ret < 0) { + dev_err(&pdev->dev, "error to get i2c config\n"); + goto error; + } + + if (!cy_i2c->i2c_config->is_master) { + ret = -EIO; + dev_err(&pdev->dev, "not an I2C master\n"); + goto error; + } + + ret = i2c_add_adapter(&cy_i2c->i2c_adapter); + if (ret != 0) { + dev_err(&pdev->dev, "failed to add i2c adapter\n"); + goto error; + } + + platform_set_drvdata(pdev, cy_i2c); + + dev_dbg(&pdev->dev, "added I2C adapter\n"); + return 0; + +error: + dev_dbg(&pdev->dev, "error occured %d\n", ret); + kfree(cy_i2c->i2c_config); + return ret; +} + +static int cyusbs23x_i2c_remove(struct platform_device *pdev) +{ + struct cyusbs_i2c *cy_i2c = platform_get_drvdata(pdev); + + dev_dbg(&pdev->dev, "%s\n", __func__); + kfree(cy_i2c->i2c_config); + i2c_del_adapter(&cy_i2c->i2c_adapter); + return 0; +} + +static struct platform_driver cyusbs23x_i2c_driver = { + .driver.name = "cyusbs23x-i2c", + .driver.owner = THIS_MODULE, + .probe = cyusbs23x_i2c_probe, + .remove = cyusbs23x_i2c_remove, +}; + +module_platform_driver(cyusbs23x_i2c_driver); + +MODULE_AUTHOR("Rajaram Regupathy <rera@xxxxxxxxxxx>"); +MODULE_AUTHOR("Muthu Mani <muth@xxxxxxxxxxx>"); +MODULE_DESCRIPTION("I2C adapter driver for CYUSBS23x"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:cyusbs23x-i2c"); -- 1.8.3.2 -- 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
