Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751905AbaLNCY7 (ORCPT ); Sat, 13 Dec 2014 21:24:59 -0500 Received: from mail-pa0-f42.google.com ([209.85.220.42]:33202 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750764AbaLNCY4 (ORCPT ); Sat, 13 Dec 2014 21:24:56 -0500 Message-ID: <548CF4F1.7070607@gmail.com> Date: Sun, 14 Dec 2014 07:54:49 +0530 From: Varka Bhadram User-Agent: Mozilla/5.0 (X11; Linux i686; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: Muthu Mani , Samuel Ortiz , Lee Jones , Wolfram Sang , Linus Walleij , Alexandre Courbot , gregkh@linuxfoundation.org, Johan Hovold CC: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, linux-gpio@vger.kernel.org, Rajaram Regupathy Subject: Re: [PATCH v5 2/3] i2c: add support for Cypress CYUSBS234 USB-I2C adapter References: <1418471264-31896-1-git-send-email-muth@cypress.com> <1418471264-31896-2-git-send-email-muth@cypress.com> In-Reply-To: <1418471264-31896-2-git-send-email-muth@cypress.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Saturday 13 December 2014 05:17 PM, Muthu Mani wrote: > 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 > Signed-off-by: Rajaram Regupathy > --- > Changes since v4: > * used interface number from interface pointer instead of separate member var > > Changes since v3: > * corrected typo > > Changes since v2: > * Retrieved the i2c transfer status using interrupt in endpoint > * Used kstrtol instead of manually parsing and scnprintf instead of sprintf > * Given i2c adapter device for dev_xxx > * cleaned up the code > > Changes since v1: > * allocated memory on heap for usb transfer data > * Used DEVICE_ATTR_xx and friends and attribute groups > * Added the device files under i2c-adapter rather than platform device > > drivers/i2c/busses/Kconfig | 12 + > drivers/i2c/busses/Makefile | 1 + > drivers/i2c/busses/i2c-cyusbs23x.c | 585 +++++++++++++++++++++++++++++++++++++ > 3 files changed, 598 insertions(+) > create mode 100644 drivers/i2c/busses/i2c-cyusbs23x.c > > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig > index b4d135c..a9cd3e2 100644 > --- a/drivers/i2c/busses/Kconfig > +++ b/drivers/i2c/busses/Kconfig > @@ -871,6 +871,18 @@ config I2C_RCAR > > comment "External I2C/SMBus adapter drivers" > > +config I2C_CYUSBS23X > + tristate "CYUSBS23x I2C adapter" > + depends on MFD_CYUSBS23X > + 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 cdac7f1..ad2b283 100644 > --- a/drivers/i2c/busses/Makefile > +++ b/drivers/i2c/busses/Makefile > @@ -86,6 +86,7 @@ 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-$(CONFIG_I2C_DLN2) += i2c-dln2.o > obj-$(CONFIG_I2C_PARPORT) += i2c-parport.o > diff --git a/drivers/i2c/busses/i2c-cyusbs23x.c b/drivers/i2c/busses/i2c-cyusbs23x.c > new file mode 100644 > index 0000000..452c370 > --- /dev/null > +++ b/drivers/i2c/busses/i2c-cyusbs23x.c > @@ -0,0 +1,585 @@ > +/* > + * 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 > + * > + * Additional contributors include: > + * Muthu Mani > + * > + * 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 > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define CY_I2C_MODE_READ 0 > +#define CY_I2C_MODE_WRITE 1 > + > +#define CY_I2C_XFER_STATUS_LEN 3 > + > +struct cyusbs_i2c_config { > + /* Frequency of operation. Only valid values are 100KHz and 400KHz */ > + u32 frequency; > + u8 slave_addr; /* Slave address to be used when in slave mode */ > + u8 is_msb_first; /* Whether to transmit MSB first */ > + /* > + * Whether block is configured as a master: > + * 1 - The block functions as I2C master; > + * 0 - The block functions as I2C slave > + */ > + u8 is_master; > + u8 s_ignore; /* Ignore general call in slave mode */ > + /* Whether to stretch clock in case of no FIFO availability */ > + u8 clock_stretch; > + /* Whether to loop back TX data to RX. Valid only for debug purposes */ > + u8 is_loopback; > + u8 reserved[6]; /* Reserved for future use */ > +} __packed; > + > +struct cyusbs_i2c { > + struct i2c_adapter i2c_adapter; > + struct cyusbs_i2c_config *i2c_config; > + struct mutex lock; > + > + bool is_stop_bit; /* set the stop bit for i2c transfer */ > + bool is_nak_bit; /* set the nak bit for i2c transfer */ > +}; > + > +#define to_cyusbs_i2c(a) container_of(a, struct cyusbs_i2c, i2c_adapter) > + > +static int cy_i2c_get_status(struct i2c_adapter *adapter, u8 *buf, u16 mode); > +static int cy_i2c_reset(struct i2c_adapter *adapter, u16 mode); > + > +static ssize_t i2c_read_status_show(struct device *d, > + struct device_attribute *attr, char *buf) > +{ > + struct i2c_adapter *adapter = to_i2c_adapter(d); > + > + /* Updates buffer with 3 bytes status (hex data) */ > + return cy_i2c_get_status(adapter, buf, CY_I2C_MODE_READ); > +} > + > +static ssize_t i2c_write_status_show(struct device *d, > + struct device_attribute *attr, char *buf) > +{ > + struct i2c_adapter *adapter = to_i2c_adapter(d); > + > + /* Updates buffer with 3 bytes status (hex data) */ > + return cy_i2c_get_status(adapter, 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; > + long value; > + struct i2c_adapter *adapter = to_i2c_adapter(d); > + > + ret = kstrtol(buf, 0, &value); > + if (ret) > + return ret; > + > + if (value != 1) > + return -EINVAL; > + > + ret = cy_i2c_reset(adapter, 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; > + long value; > + struct i2c_adapter *adapter = to_i2c_adapter(d); > + > + ret = kstrtol(buf, 0, &value); > + if (ret) > + return ret; > + > + if (value != 1) > + return -EINVAL; > + > + ret = cy_i2c_reset(adapter, 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 scnprintf(buf, 3, "%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); > + long value; > + int ret; > + > + ret = kstrtol(buf, 0, &value); > + if (ret) > + return ret; > + > + if (value != 0 && value != 1) > + return -EINVAL; > + > + cy_i2c->is_stop_bit = (bool)value; > + > + 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 scnprintf(buf, 3, "%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); > + long value; > + int ret; > + > + ret = kstrtol(buf, 0, &value); > + if (ret) > + return ret; > + > + if (value != 0 && value != 1) > + return -EINVAL; > + > + cy_i2c->is_nak_bit = (bool)value; > + > + 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 i2c_adapter *adapter, u8 *buf, u16 mode) > +{ > + int ret; > + u16 wIndex, wValue, scb_index; > + u8 *data; > + struct cyusbs23x *cyusbs = (struct cyusbs23x *)adapter->algo_data; > + struct cyusbs_i2c *cy_i2c = to_cyusbs_i2c(adapter); > + u8 ifnum = cyusbs->usb_intf->cur_altsetting->desc.bInterfaceNumber; > + > + scb_index = ifnum & 0x01; > + wValue = ((scb_index << CY_SCB_INDEX_SHIFT) | mode); > + wIndex = 0; One line space.. > + data = kmalloc(CY_I2C_XFER_STATUS_LEN, GFP_KERNEL); > + if (data == NULL) > + return -ENOMEM; > + if(!data) return -ENOMEM; > + mutex_lock(&cy_i2c->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, > + CY_USBS_CTRL_XFER_TIMEOUT); > + mutex_unlock(&cy_i2c->lock); > + if (ret != CY_I2C_XFER_STATUS_LEN) { > + dev_err(&adapter->dev, "%s: failed to get status: %d", > + __func__, ret); > + ret = usb_translate_errors(ret); > + goto status_error; > + } > + > + memcpy(buf, data, CY_I2C_XFER_STATUS_LEN); > + buf[CY_I2C_XFER_STATUS_LEN] = 0; > + > + dev_dbg(&adapter->dev, "%s: %02x %02x %02x\n", __func__, > + buf[0], buf[1], buf[2]); > + > +status_error: > + kfree(data); > + return ret; > +} > + > +static int cy_i2c_reset(struct i2c_adapter *adapter, u16 mode) > +{ > + int ret; > + u16 wIndex, wValue, scb_index; > + struct cyusbs23x *cyusbs = (struct cyusbs23x *)adapter->algo_data; > + struct cyusbs_i2c *cy_i2c = to_cyusbs_i2c(adapter); > + u8 ifnum = cyusbs->usb_intf->cur_altsetting->desc.bInterfaceNumber; > + > + scb_index = ifnum & 0x01; > + wValue = ((scb_index << CY_SCB_INDEX_SHIFT) | mode); > + wIndex = 0; > + > + mutex_lock(&cy_i2c->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, CY_USBS_CTRL_XFER_TIMEOUT); > + mutex_unlock(&cy_i2c->lock); > + if (ret) { > + dev_err(&adapter->dev, "%s: failed to reset: %d", > + __func__, ret); > + ret = usb_translate_errors(ret); > + } > + > + return ret; > +} > + > +static int cy_i2c_recv_status(struct i2c_adapter *adapter) > +{ > + int ret, actual_len; > + u8 *data; > + struct cyusbs23x *cyusbs = (struct cyusbs23x *)adapter->algo_data; > + > + data = kmalloc(CY_I2C_XFER_STATUS_LEN, GFP_KERNEL); > + if (data == NULL) > + return -ENOMEM; > + if(!data) return -ENOMEM; > + /* read the i2c transfer status */ > + ret = usb_interrupt_msg(cyusbs->usb_dev, > + usb_rcvintpipe(cyusbs->usb_dev, cyusbs->intr_in_ep_num), > + data, CY_I2C_XFER_STATUS_LEN, &actual_len, > + CY_USBS_INTR_XFER_TIMEOUT); > + if (ret < 0) { > + dev_err(&adapter->dev, > + "Failed to read from interrupt ep: %d\n", ret); > + ret = usb_translate_errors(ret); > + goto intr_ep_error; > + } > + > + dev_dbg(&adapter->dev, "%s: %02x %02x %02x\n", __func__, > + data[0], data[1], data[2]); > + > + if (data[0] & 0x1) > + ret = -ETIMEDOUT; > + > +intr_ep_error: > + kfree(data); > + return ret; > +} > + > +static int cy_get_i2c_config(struct cyusbs23x *cyusbs, > + struct cyusbs_i2c *cy_i2c) > +{ > + int ret; > + u16 scb_index; > + u8 ifnum = cyusbs->usb_intf->cur_altsetting->desc.bInterfaceNumber; > + > + scb_index = (ifnum & 0x01) << CY_SCB_INDEX_SHIFT; > + > + 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), CY_USBS_CTRL_XFER_TIMEOUT); > + if (ret != sizeof(*cy_i2c->i2c_config)) { > + dev_err(&cyusbs->usb_intf->dev, "%s: %d\n", > + __func__, ret); > + ret = usb_translate_errors(ret); > + goto config_error; > + } > + > + dev_dbg(&cyusbs->usb_intf->dev, > + "%s: freq=%d, slave_addr=0x%02x, msb_first=%d, master=%d, ignore=%d, clock_stretch=%d, loopback=%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); > + > +config_error: > + 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, scb_index; > + u8 ifnum = cyusbs->usb_intf->cur_altsetting->desc.bInterfaceNumber; > + > + scb_index = (ifnum & 0x01) << CY_SCB_INDEX_SHIFT; > + slave_addr = (slave_addr & 0x7F); > + wValue = scb_index | cy_i2c->is_stop_bit | cy_i2c->is_nak_bit << 1; > + wValue |= (slave_addr << 8); > + wIndex = length; > + > + dev_dbg(&cy_i2c->i2c_adapter.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, CY_USBS_CTRL_XFER_TIMEOUT); > + > + return ret; > +} > + > +static int cy_i2c_read(struct i2c_adapter *adapter, struct i2c_msg *msgs) > +{ > + int ret; > + int actual_read_len = 0; > + struct cyusbs23x *cyusbs = (struct cyusbs23x *)adapter->algo_data; > + > + dev_dbg(&adapter->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, CY_USBS_BULK_XFER_TIMEOUT); > + if (ret) > + dev_err(&adapter->dev, > + "read %d/%d returned %d\n", > + actual_read_len, msgs[0].len, ret); > + > + ret = cy_i2c_recv_status(adapter); > + > + return ret; > +} > + > +static int cy_i2c_write(struct i2c_adapter *adapter, struct i2c_msg *msgs) > +{ > + int ret; > + int actual_write_len = 0; > + struct cyusbs23x *cyusbs = (struct cyusbs23x *)adapter->algo_data; > + > + dev_dbg(&adapter->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, CY_USBS_BULK_XFER_TIMEOUT); > + if (ret) > + dev_err(&adapter->dev, > + "write %d/%d returned %d\n", > + actual_write_len, msgs[0].len, ret); > + > + ret = cy_i2c_recv_status(adapter); > + > + 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(&cy_i2c->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(adapter, 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(adapter, msgs); > + if (ret) { > + dev_err(&adapter->dev, > + "Write failed with error code %d\n", ret); > + goto io_error; > + } > + } > + mutex_unlock(&cy_i2c->lock); > + return ret; > + > +io_error: > + mutex_unlock(&cy_i2c->lock); > + return ret; > +} > + > +static u32 cy_i2c_func(struct i2c_adapter *adapter) > +{ > + 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; > + dto... > + cy_i2c->i2c_config = devm_kzalloc(&pdev->dev, > + sizeof(struct cyusbs_i2c_config), > + GFP_KERNEL); > + if (cy_i2c->i2c_config == NULL) > + return -ENOMEM; > + dto... -- Thanks and Regards, Varka Bhadram. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/