From: Sascha Hauer <[email protected]> This driver provides a I2C bus driver for the CGEB interface found on some Congatec x86 modules. No devices are registered on the bus, the user has to do this via the i2c device /sys interface.
Signed-off-by: Sascha Hauer <[email protected]> Signed-off-by: Christian Gmeiner <[email protected]> --- drivers/i2c/busses/Kconfig | 7 ++ drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-congatec-cgeb.c | 205 +++++++++++++++++++++++++++++++++ 3 files changed, 213 insertions(+) create mode 100644 drivers/i2c/busses/i2c-congatec-cgeb.c diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 2255af2..9c49d37 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -937,6 +937,13 @@ config I2C_RCAR This driver can also be built as a module. If so, the module will be called i2c-rcar. +config I2C_CONGATEC_CGEB + tristate "Congatec CGEB I2C driver" + depends on MFD_CONGATEC_CGEB + help + This driver provides support for the I2C busses accssable via + the Congatec CGEB interface found on Congatec boards. + comment "External I2C/SMBus adapter drivers" config I2C_DIOLAN_U2C diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index cdf941d..29e7ea7 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -91,6 +91,7 @@ obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o obj-$(CONFIG_I2C_XLR) += i2c-xlr.o obj-$(CONFIG_I2C_XLP9XX) += i2c-xlp9xx.o obj-$(CONFIG_I2C_RCAR) += i2c-rcar.o +obj-$(CONFIG_I2C_CONGATEC_CGEB) += i2c-congatec-cgeb.o # External I2C/SMBus adapter drivers obj-$(CONFIG_I2C_DIOLAN_U2C) += i2c-diolan-u2c.o diff --git a/drivers/i2c/busses/i2c-congatec-cgeb.c b/drivers/i2c/busses/i2c-congatec-cgeb.c new file mode 100644 index 0000000..7802790 --- /dev/null +++ b/drivers/i2c/busses/i2c-congatec-cgeb.c @@ -0,0 +1,205 @@ +/* + * CGEB i2c driver + * + * (c) 2011 Sascha Hauer, Pengutronix + * + * 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; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/i2c.h> +#include <linux/mfd/congatec-cgeb.h> + +#define CG_I2C_FLAG_START 0x00080 /* send START condition */ +#define CG_I2C_FLAG_STOP 0x00040 /* send STOP condition */ +#define CG_I2C_FLAG_ALL_ACK 0x08000 /* send ACK on all read bytes */ +#define CG_I2C_FLAG_ALL_NAK 0x04000 /* send NAK on all read bytes */ + +struct cgeb_i2c_priv { + struct cgeb_board_data *board; + struct i2c_adapter adapter; + int unit; +}; + +static u32 cgeb_i2c_func(struct i2c_adapter *adapter) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static int cgeb_i2c_set_speed(struct cgeb_i2c_priv *priv, int speed) +{ + struct cgeb_function_parameters fps; + + memset(&fps, 0, sizeof(fps)); + + fps.unit = priv->unit; + fps.pars[0] = speed; + + return cgeb_call(priv->board, &fps, CgebI2CSetFrequency); +} + +static int cgeb_i2c_xfer(struct i2c_adapter *adapter, + struct i2c_msg *msgs, int num) +{ + struct cgeb_function_parameters fps; + int i, ret; + unsigned long flags = CG_I2C_FLAG_START; + struct cgeb_i2c_priv *priv = i2c_get_adapdata(adapter); + unsigned long rdlen, wrlen; + unsigned char *rdbuf, *wrbuf, *raw_wrbuf; + unsigned short lmax = 0; + + /* + * With cgeb the I2C address is part of the write data + * buffer, so allocate a buffer with the length of the + * longest write buffer + 1 + */ + for (i = 0; i < num; i++) + if (!(msgs[i].flags & I2C_M_RD)) + lmax = max(lmax, msgs[i].len); + + raw_wrbuf = kmalloc(lmax + 1, GFP_KERNEL); + if (!raw_wrbuf) + return -ENOMEM; + + for (i = 0; i < num; i++) { + if (msgs[i].flags & I2C_M_RD) { + rdbuf = msgs[i].buf; + rdlen = msgs[i].len; + wrbuf = NULL; + wrlen = 0; + } else { + rdbuf = NULL; + rdlen = 0; + wrbuf = msgs[i].buf; + wrlen = msgs[i].len; + } + + raw_wrbuf[0] = msgs[i].addr << 1; + if (wrlen) + memcpy(&raw_wrbuf[1], wrbuf, wrlen); + + if (msgs[i].flags & I2C_M_RD) + raw_wrbuf[0] |= 1; + + if (i == num - 1) + flags |= CG_I2C_FLAG_STOP; + + dev_dbg(&adapter->dev, + "%s: rd: %p/%ld wr: %p/%ld flags: 0x%08lx %s\n", + __func__, rdbuf, rdlen, raw_wrbuf, wrlen + 1, + flags, + msgs[i].flags & I2C_M_RD ? "READ" : "WRITE"); + + memset(&fps, 0, sizeof(fps)); + + fps.unit = priv->unit; + fps.pars[0] = wrlen + 1; + fps.pars[1] = rdlen; + fps.pars[2] = flags; + fps.iptr = raw_wrbuf; + fps.optr = rdbuf; + + ret = cgeb_call(priv->board, &fps, CgebI2CTransfer); + if (ret) { + ret = -EREMOTEIO; + goto out; + } + } + + ret = num; + +out: + kfree(raw_wrbuf); + + return ret; +} + +static struct i2c_algorithm cgeb_i2c_algo = { + .master_xfer = cgeb_i2c_xfer, + .functionality = cgeb_i2c_func, +}; + +static int cgeb_i2c_probe(struct platform_device *pdev) +{ + struct cgeb_i2c_priv *priv; + struct cgeb_pdata *pdata = pdev->dev.platform_data; + int ret; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + strcpy(priv->adapter.name, pdev->name); + priv->adapter.owner = THIS_MODULE; + priv->adapter.algo = &cgeb_i2c_algo; + priv->adapter.dev.parent = &pdev->dev; + priv->unit = pdata->unit; + priv->board = pdata->board; + i2c_set_adapdata(&priv->adapter, priv); + + platform_set_drvdata(pdev, priv); + + ret = cgeb_i2c_set_speed(priv, 400000); + if (ret) + /* + * not a critical error, we can continue with the default speed. + */ + dev_warn(&pdev->dev, "Could not set speed to 400KHz\n"); + + ret = i2c_add_adapter(&priv->adapter); + if (ret < 0) { + dev_err(&pdev->dev, "registration failed\n"); + return ret; + } + + dev_info(&pdev->dev, "registered\n"); + + return 0; +}; + +static int cgeb_i2c_remove(struct platform_device *pdev) +{ + struct cgeb_i2c_priv *priv = platform_get_drvdata(pdev); + + i2c_del_adapter(&priv->adapter); + + platform_set_drvdata(pdev, NULL); + + return 0; +} + +static struct platform_driver cgeb_i2c_driver = { + .probe = cgeb_i2c_probe, + .remove = __exit_p(cgeb_i2c_remove), + .driver = { + .name = "cgeb-i2c", + .owner = THIS_MODULE, + }, +}; + +static int __init cgeb_i2c_driver_init(void) +{ + return platform_driver_register(&cgeb_i2c_driver); +} + +static void __exit cgeb_i2c_driver_exit(void) +{ + platform_driver_unregister(&cgeb_i2c_driver); +} + +module_init(cgeb_i2c_driver_init); +module_exit(cgeb_i2c_driver_exit); + +MODULE_AUTHOR("Sascha Hauer <[email protected]>"); +MODULE_DESCRIPTION("cgeb i2c driver"); +MODULE_LICENSE("GPL"); + -- 2.4.2 -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
