Hi Ben,

How about this patch? Can it be applied?

Thanks!

quoted text
> This patch is to add i2c driver support for nuc900.
>
> v1->v2 changes:
> Address the comments of Ben Dooks
>
> (1) Document registers Macro definitions.
> (1) Modify some documents apply to kernel doc style.
> (2) clk_get shouldn't need the second argument, so remove it.
> (3) clk_get_rate() should be used.
> (5) Add irq IRQF_SHARED flag.
> (6) change i2s_nuc900_irq_nextbyte() declaration type from 'int' to 'void'
>    it does not need return value.
> (7) To enable irq easier.
>
> Signed-off-by: Wan ZongShun <mcuos.com@gmail.com>
> Reviewed-by: Marek Vasut <marek.vasut@gmail.com>
> Reviewed-by: Baruch Siach <baruch@tkos.co.il>
> ---
>  arch/arm/mach-w90x900/include/mach/i2c.h |    9 +
>  drivers/i2c/busses/Kconfig               |    7 +
>  drivers/i2c/busses/Makefile              |    1 +
>  drivers/i2c/busses/i2c-nuc900.c          |  709 ++++++++++++++++++++++++++++++
>  4 files changed, 726 insertions(+), 0 deletions(-)
>  create mode 100644 arch/arm/mach-w90x900/include/mach/i2c.h
>  create mode 100644 drivers/i2c/busses/i2c-nuc900.c
>
> diff --git a/arch/arm/mach-w90x900/include/mach/i2c.h b/arch/arm/mach-w90x900/include/mach/i2c.h
> new file mode 100644
> index 0000000..9ffb12d
> --- /dev/null
> +++ b/arch/arm/mach-w90x900/include/mach/i2c.h
> @@ -0,0 +1,9 @@
> +#ifndef __ASM_ARCH_NUC900_I2C_H
> +#define __ASM_ARCH_NUC900_I2C_H
> +
> +struct nuc900_platform_i2c {
> +       int             bus_num;
> +       unsigned long   bus_freq;
> +};
> +
> +#endif /* __ASM_ARCH_NUC900_I2C_H */
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index bceafbf..ee284d2 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -448,6 +448,13 @@ config I2C_NOMADIK
>          If you say yes to this option, support will be included for the
>          I2C interface from ST-Ericsson's Nomadik and Ux500 architectures.
>
> +config I2C_NUC900
> +       tristate "NUC900 I2C Driver"
> +       depends on ARCH_W90X900
> +       help
> +         Say Y here to include support for I2C controller in the
> +         Winbond/Nuvoton NUC900 based System-on-Chip devices.
> +
>  config I2C_OCORES
>        tristate "OpenCores I2C Controller"
>        depends on EXPERIMENTAL
> diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
> index 936880b..c3ef492 100644
> --- a/drivers/i2c/busses/Makefile
> +++ b/drivers/i2c/busses/Makefile
> @@ -43,6 +43,7 @@ obj-$(CONFIG_I2C_IXP2000)     += i2c-ixp2000.o
>  obj-$(CONFIG_I2C_MPC)          += i2c-mpc.o
>  obj-$(CONFIG_I2C_MV64XXX)      += i2c-mv64xxx.o
>  obj-$(CONFIG_I2C_NOMADIK)      += i2c-nomadik.o
> +obj-$(CONFIG_I2C_NUC900)       += i2c-nuc900.o
>  obj-$(CONFIG_I2C_OCORES)       += i2c-ocores.o
>  obj-$(CONFIG_I2C_OMAP)         += i2c-omap.o
>  obj-$(CONFIG_I2C_PASEMI)       += i2c-pasemi.o
> diff --git a/drivers/i2c/busses/i2c-nuc900.c b/drivers/i2c/busses/i2c-nuc900.c
> new file mode 100644
> index 0000000..7a13b28
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-nuc900.c
> @@ -0,0 +1,709 @@
> +/*
> + * linux/drivers/i2c/busses/i2c-nuc900.c
> + *
> + * Copyright (c) 2010 Nuvoton technology corporation.
> + *
> + * This driver based on S3C2410 I2C driver of Ben Dooks <ben@simtec.co.uk>.
> + * Written by Wan ZongShun <mcuos.com@gmail.com>
> + *
> + * 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.
> + *
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +
> +#include <linux/i2c.h>
> +#include <linux/i2c-id.h>
> +#include <linux/init.h>
> +#include <linux/time.h>
> +#include <linux/interrupt.h>
> +#include <linux/delay.h>
> +#include <linux/errno.h>
> +#include <linux/err.h>
> +#include <linux/platform_device.h>
> +#include <linux/clk.h>
> +#include <linux/cpufreq.h>
> +#include <linux/slab.h>
> +#include <linux/io.h>
> +
> +#include <mach/mfp.h>
> +#include <mach/i2c.h>
> +
> +/* nuc900 i2c registers offset */
> +
> +#define CSR            0x00
> +#define DIVIDER                0x04
> +#define CMDR           0x08
> +#define SWR            0x0C
> +#define RXR            0x10
> +#define TXR            0x14
> +
> +/* nuc900 i2c CSR register bits */
> +
> +#define IRQEN          0x003
> +#define I2CBUSY                0x400
> +#define I2CSTART       0x018
> +#define IRQFLAG                0x004
> +#define ARBIT_LOST     0x200
> +#define SLAVE_ACK      0x800
> +
> +/* nuc900 i2c CMDR register bits */
> +
> +#define I2C_CMD_START  0x10
> +#define I2C_CMD_STOP   0x08
> +#define I2C_CMD_READ   0x04
> +#define I2C_CMD_WRITE  0x02
> +#define I2C_CMD_NACK   0x01
> +
> +/* i2c controller state */
> +
> +enum nuc900_i2c_state {
> +       STATE_IDLE,
> +       STATE_START,
> +       STATE_READ,
> +       STATE_WRITE,
> +       STATE_STOP
> +};
> +
> +/* i2c controller private data */
> +
> +struct nuc900_i2c {
> +       spinlock_t              lock;
> +       wait_queue_head_t       wait;
> +
> +       struct i2c_msg          *msg;
> +       unsigned int            msg_num;
> +       unsigned int            msg_idx;
> +       unsigned int            msg_ptr;
> +       unsigned int            irq;
> +
> +       enum nuc900_i2c_state   state;
> +
> +       void __iomem            *regs;
> +       struct clk              *clk;
> +       struct device           *dev;
> +       struct resource         *ioarea;
> +       struct i2c_adapter      adap;
> +};
> +
> +/* nuc900_i2c_master_complete
> + *
> + * complete the message and wake up the caller, using the given return code,
> + * or zero to mean ok.
> +*/
> +
> +static inline void nuc900_i2c_master_complete(struct nuc900_i2c *i2c, int ret)
> +{
> +       dev_dbg(i2c->dev, "master_complete %d\n", ret);
> +
> +       i2c->msg_ptr = 0;
> +       i2c->msg = NULL;
> +       i2c->msg_idx++;
> +       i2c->msg_num = 0;
> +       if (ret)
> +               i2c->msg_idx = ret;
> +
> +       wake_up(&i2c->wait);
> +}
> +
> +/* irq enable/disable functions */
> +
> +static inline void nuc900_i2c_disable_irq(struct nuc900_i2c *i2c)
> +{
> +       unsigned long tmp;
> +
> +       tmp = readl(i2c->regs + CSR);
> +       writel(tmp & ~IRQEN, i2c->regs + CSR);
> +}
> +
> +static inline void nuc900_i2c_enable_irq(struct nuc900_i2c *i2c)
> +{
> +       unsigned long tmp;
> +
> +       tmp = readl(i2c->regs + CSR);
> +       writel(tmp | IRQEN, i2c->regs + CSR);
> +}
> +
> +
> +/* nuc900_i2c_message_start
> + *
> + * put the start of a message onto the bus
> +*/
> +
> +static void nuc900_i2c_message_start(struct nuc900_i2c *i2c,
> +                                     struct i2c_msg *msg)
> +{
> +       unsigned int addr = (msg->addr & 0x7f) << 1;
> +
> +       if (msg->flags & I2C_M_RD)
> +               addr |= 0x1;
> +       writel(addr & 0xff, i2c->regs + TXR);
> +       writel(I2C_CMD_START | I2C_CMD_WRITE, i2c->regs + CMDR);
> +}
> +
> +static inline void nuc900_i2c_stop(struct nuc900_i2c *i2c, int ret)
> +{
> +
> +       dev_dbg(i2c->dev, "STOP\n");
> +
> +       /* stop the transfer */
> +       i2c->state = STATE_STOP;
> +       writel(I2C_CMD_STOP, i2c->regs + CMDR);
> +
> +       nuc900_i2c_master_complete(i2c, ret);
> +       nuc900_i2c_disable_irq(i2c);
> +}
> +
> +/* helper functions to determine the current state in the set of
> + * messages we are sending
> +*/
> +
> +/* is_lastmsg()
> + *
> + * returns TRUE if the current message is the last in the set
> +*/
> +
> +static inline int is_lastmsg(struct nuc900_i2c *i2c)
> +{
> +       return i2c->msg_idx >= (i2c->msg_num - 1);
> +}
> +
> +/* is_msglast
> + *
> + * returns TRUE if we this is the last byte in the current message
> +*/
> +
> +static inline int is_msglast(struct nuc900_i2c *i2c)
> +{
> +       return i2c->msg_ptr == i2c->msg->len-1;
> +}
> +
> +/* is_msgend
> + *
> + * returns TRUE if we reached the end of the current message
> +*/
> +
> +static inline int is_msgend(struct nuc900_i2c *i2c)
> +{
> +       return i2c->msg_ptr >= i2c->msg->len;
> +}
> +
> +/* i2c_nuc900_irq_nextbyte
> + *
> + * process an interrupt and work out what to do
> + */
> +
> +static void i2c_nuc900_irq_nextbyte(struct nuc900_i2c *i2c,
> +                                                       unsigned long iicstat)
> +{
> +       unsigned char byte;
> +
> +       switch (i2c->state) {
> +
> +       case STATE_IDLE:
> +               dev_err(i2c->dev, "%s: called in STATE_IDLE\n", __func__);
> +               break;
> +
> +       case STATE_STOP:
> +               dev_err(i2c->dev, "%s: called in STATE_STOP\n", __func__);
> +               nuc900_i2c_disable_irq(i2c);
> +               break;
> +
> +       case STATE_START:
> +               /* last thing we did was send a start condition on the
> +                * bus, or started a new i2c message
> +                */
> +
> +               if (iicstat & SLAVE_ACK &&
> +                   !(i2c->msg->flags & I2C_M_IGNORE_NAK)) {
> +                       /* ack was not received... */
> +
> +                       dev_dbg(i2c->dev, "ack was not received\n");
> +                       nuc900_i2c_stop(i2c, -ENXIO);
> +                       break;
> +               }
> +
> +               if (i2c->msg->flags & I2C_M_RD)
> +                       i2c->state = STATE_READ;
> +               else
> +                       i2c->state = STATE_WRITE;
> +
> +               /* terminate the transfer if there is nothing to do
> +                * as this is used by the i2c probe to find devices.
> +               */
> +
> +               if (is_lastmsg(i2c) && i2c->msg->len == 0) {
> +                       nuc900_i2c_stop(i2c, 0);
> +                       break;
> +               }
> +
> +               if (i2c->state == STATE_READ)
> +                       goto prepare_read;
> +
> +               /* fall through to the write state, as we will need to
> +                * send a byte as well
> +               */
> +
> +       case STATE_WRITE:
> +               /* we are writing data to the device... check for the
> +                * end of the message, and if so, work out what to do
> +                */
> +
> +               if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) {
> +                       if (iicstat & SLAVE_ACK) {
> +                               dev_dbg(i2c->dev, "WRITE: No Ack\n");
> +
> +                               nuc900_i2c_stop(i2c, -ECONNREFUSED);
> +                               break;
> +                       }
> +               }
> +
> +retry_write:
> +
> +               if (!is_msgend(i2c)) {
> +                       byte = i2c->msg->buf[i2c->msg_ptr++];
> +                       writeb(byte, i2c->regs + TXR);
> +                       writel(I2C_CMD_WRITE, i2c->regs + CMDR);
> +
> +               } else if (!is_lastmsg(i2c)) {
> +                       /* we need to go to the next i2c message */
> +
> +                       dev_dbg(i2c->dev, "WRITE: Next Message\n");
> +
> +                       i2c->msg_ptr = 0;
> +                       i2c->msg_idx++;
> +                       i2c->msg++;
> +
> +                       /* check to see if we need to do another message */
> +                       if (i2c->msg->flags & I2C_M_NOSTART) {
> +
> +                               if (i2c->msg->flags & I2C_M_RD) {
> +                                       /* cannot do this, the controller
> +                                        * forces us to send a new START
> +                                        * when we change direction
> +                                       */
> +
> +                                       nuc900_i2c_stop(i2c, -EINVAL);
> +                               }
> +
> +                               goto retry_write;
> +                       } else {
> +                               /* send the new start */
> +                               nuc900_i2c_message_start(i2c, i2c->msg);
> +                               i2c->state = STATE_START;
> +                       }
> +
> +               } else {
> +                       /* send stop */
> +
> +                       nuc900_i2c_stop(i2c, 0);
> +               }
> +               break;
> +
> +       case STATE_READ:
> +               /* we have a byte of data in the data register, do
> +                * something with it, and then work out wether we are
> +                * going to do any more read/write
> +                */
> +
> +               byte = readb(i2c->regs + RXR);
> +               i2c->msg->buf[i2c->msg_ptr++] = byte;
> +
> +prepare_read:
> +               if (is_msglast(i2c)) {
> +                       /* last byte of buffer */
> +
> +                       if (is_lastmsg(i2c))
> +                               writel(I2C_CMD_READ | I2C_CMD_NACK,
> +                                                       i2c->regs + CMDR);
> +
> +               } else if (is_msgend(i2c)) {
> +                       /* ok, we've read the entire buffer, see if there
> +                        * is anything else we need to do
> +                       */
> +
> +                       if (is_lastmsg(i2c)) {
> +                               /* last message, send stop and complete */
> +                               dev_dbg(i2c->dev, "READ: Send Stop\n");
> +
> +                               nuc900_i2c_stop(i2c, 0);
> +                       } else {
> +                               /* go to the next transfer */
> +                               dev_dbg(i2c->dev, "READ: Next Transfer\n");
> +
> +                               i2c->msg_ptr = 0;
> +                               i2c->msg_idx++;
> +                               i2c->msg++;
> +
> +                               writel(I2C_CMD_READ, i2c->regs + CMDR);
> +                       }
> +
> +               } else {
> +                       writel(I2C_CMD_READ, i2c->regs + CMDR);
> +               }
> +
> +               break;
> +       }
> +}
> +
> +/* nuc900_i2c_irq
> + *
> + * top level IRQ servicing routine
> +*/
> +
> +static irqreturn_t nuc900_i2c_irq(int irqno, void *dev_id)
> +{
> +       struct nuc900_i2c *i2c = dev_id;
> +       unsigned long status;
> +
> +       status = readl(i2c->regs + CSR);
> +       writel(status | IRQFLAG, i2c->regs + CSR);
> +
> +       if (status & ARBIT_LOST) {
> +               /* deal with arbitration loss */
> +               dev_err(i2c->dev, "deal with arbitration loss\n");
> +               goto out;
> +       }
> +
> +       if (i2c->state == STATE_IDLE) {
> +               dev_dbg(i2c->dev, "IRQ: error i2c->state == IDLE\n");
> +               goto out;
> +       }
> +
> +       /* pretty much this leaves us with the fact that we've
> +        * transmitted or received whatever byte we last sent
> +       */
> +
> +       i2c_nuc900_irq_nextbyte(i2c, status);
> +
> + out:
> +       return IRQ_HANDLED;
> +}
> +
> +
> +/* nuc900_i2c_set_master
> + *
> + * get the i2c bus for a master transaction
> +*/
> +
> +static int nuc900_i2c_set_master(struct nuc900_i2c *i2c)
> +{
> +       int timeout = 400;
> +
> +       while (timeout-- > 0) {
> +               if (((readl(i2c->regs + SWR) & I2CSTART) == I2CSTART) &&
> +                               ((readl(i2c->regs + CSR) & I2CBUSY) == 0)) {
> +                       return 0;
> +               }
> +
> +               msleep(1);
> +       }
> +
> +       return -ETIMEDOUT;
> +}
> +
> +/* nuc900_i2c_doxfer
> + *
> + * this starts an i2c transfer
> +*/
> +
> +static int nuc900_i2c_doxfer(struct nuc900_i2c *i2c,
> +                             struct i2c_msg *msgs, int num)
> +{
> +       unsigned long iicstat, timeout;
> +       int spins = 20;
> +       int ret;
> +
> +       ret = nuc900_i2c_set_master(i2c);
> +       if (ret != 0) {
> +               dev_err(i2c->dev, "cannot get bus (error %d)\n", ret);
> +               ret = -EAGAIN;
> +               goto out;
> +       }
> +
> +       spin_lock_irq(&i2c->lock);
> +
> +       i2c->msg     = msgs;
> +       i2c->msg_num = num;
> +       i2c->msg_ptr = 0;
> +       i2c->msg_idx = 0;
> +       i2c->state   = STATE_START;
> +
> +       nuc900_i2c_message_start(i2c, msgs);
> +       spin_unlock_irq(&i2c->lock);
> +
> +       timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
> +
> +       ret = i2c->msg_idx;
> +
> +       /* having these next two as dev_err() makes life very
> +        * noisy when doing an i2cdetect
> +       */
> +
> +       if (timeout == 0)
> +               dev_dbg(i2c->dev, "timeout\n");
> +       else if (ret != num)
> +               dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret);
> +
> +       /* ensure the stop has been through the bus */
> +
> +       dev_dbg(i2c->dev, "waiting for bus idle\n");
> +
> +       /* first, try busy waiting briefly */
> +       do {
> +               iicstat = readl(i2c->regs + CSR);
> +       } while ((iicstat & I2CBUSY) && --spins);
> +
> +       /* if that timed out sleep */
> +       if (!spins) {
> +               msleep(1);
> +               iicstat = readl(i2c->regs + CSR);
> +       }
> +
> +       if (iicstat & I2CBUSY)
> +               dev_warn(i2c->dev, "timeout waiting for bus idle\n");
> +
> + out:
> +       return ret;
> +}
> +
> +/* nuc900_i2c_xfer
> + *
> + * first port of call from the i2c bus code when an message needs
> + * transferring across the i2c bus.
> +*/
> +
> +static int nuc900_i2c_xfer(struct i2c_adapter *adap,
> +                       struct i2c_msg *msgs, int num)
> +{
> +       struct nuc900_i2c *i2c = (struct nuc900_i2c *)adap->algo_data;
> +       int retry;
> +       int ret;
> +
> +       nuc900_i2c_enable_irq(i2c);
> +
> +       for (retry = 0; retry < adap->retries; retry++) {
> +
> +               ret = nuc900_i2c_doxfer(i2c, msgs, num);
> +
> +               if (ret != -EAGAIN)
> +                       return ret;
> +
> +               dev_dbg(i2c->dev, "Retrying transmission (%d)\n", retry);
> +
> +               udelay(100);
> +       }
> +
> +       return -EREMOTEIO;
> +}
> +
> +/* declare our i2c functionality */
> +static u32 nuc900_i2c_func(struct i2c_adapter *adap)
> +{
> +       return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING;
> +}
> +
> +/* i2c bus registration info */
> +
> +static const struct i2c_algorithm nuc900_i2c_algorithm = {
> +       .master_xfer            = nuc900_i2c_xfer,
> +       .functionality          = nuc900_i2c_func,
> +};
> +
> +/* nuc900_i2c_probe
> + *
> + * called by the bus driver when a suitable device is found
> +*/
> +
> +static int __devinit nuc900_i2c_probe(struct platform_device *pdev)
> +{
> +       struct nuc900_i2c *i2c;
> +       struct nuc900_platform_i2c *pdata;
> +       struct resource *res;
> +       int ret;
> +
> +       pdata = pdev->dev.platform_data;
> +       if (!pdata) {
> +               dev_err(&pdev->dev, "no platform data\n");
> +               return -EINVAL;
> +       }
> +
> +       i2c = kzalloc(sizeof(struct nuc900_i2c), GFP_KERNEL);
> +       if (!i2c) {
> +               dev_err(&pdev->dev, "no memory for state\n");
> +               return -ENOMEM;
> +       }
> +
> +       strlcpy(i2c->adap.name, "nuc900-i2c0", sizeof(i2c->adap.name));
> +       i2c->adap.owner   = THIS_MODULE;
> +       i2c->adap.algo    = &nuc900_i2c_algorithm;
> +       i2c->adap.retries = 2;
> +       i2c->adap.class   = I2C_CLASS_HWMON | I2C_CLASS_SPD;
> +
> +       spin_lock_init(&i2c->lock);
> +       init_waitqueue_head(&i2c->wait);
> +
> +       /* find the clock and enable it */
> +
> +       i2c->dev = &pdev->dev;
> +       i2c->clk = clk_get(&pdev->dev, NULL);
> +       if (IS_ERR(i2c->clk)) {
> +               dev_err(&pdev->dev, "cannot get clock\n");
> +               ret = -ENOENT;
> +               goto err_noclk;
> +       }
> +
> +       dev_dbg(&pdev->dev, "clock source %p\n", i2c->clk);
> +
> +       clk_enable(i2c->clk);
> +
> +       /* map the registers */
> +
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       if (res == NULL) {
> +               dev_err(&pdev->dev, "cannot find IO resource\n");
> +               ret = -ENOENT;
> +               goto err_clk;
> +       }
> +
> +       i2c->ioarea = request_mem_region(res->start, resource_size(res),
> +                                        pdev->name);
> +
> +       if (i2c->ioarea == NULL) {
> +               dev_err(&pdev->dev, "cannot request IO\n");
> +               ret = -ENXIO;
> +               goto err_clk;
> +       }
> +
> +       i2c->regs = ioremap(res->start, resource_size(res));
> +
> +       if (i2c->regs == NULL) {
> +               dev_err(&pdev->dev, "cannot map IO\n");
> +               ret = -ENXIO;
> +               goto err_ioarea;
> +       }
> +
> +       dev_dbg(&pdev->dev, "registers %p (%p, %p)\n",
> +               i2c->regs, i2c->ioarea, res);
> +
> +       /* setup info block for the i2c core */
> +
> +       i2c->adap.algo_data = i2c;
> +       i2c->adap.dev.parent = &pdev->dev;
> +
> +       mfp_set_groupg(&pdev->dev);
> +
> +       clk_get_rate(i2c->clk);
> +
> +       ret = (i2c->clk.apbfreq)/(pdata->bus_freq * 5) - 1;
> +       writel(ret & 0xffff, i2c->regs + DIVIDER);
> +
> +       /* find the IRQ for this unit (note, this relies on the init call to
> +        * ensure no current IRQs pending
> +        */
> +
> +       i2c->irq = ret = platform_get_irq(pdev, 0);
> +       if (ret <= 0) {
> +               dev_err(&pdev->dev, "cannot find IRQ\n");
> +               goto err_iomap;
> +       }
> +
> +       ret = request_irq(i2c->irq, nuc900_i2c_irq, IRQF_DISABLED | IRQF_SHARED,
> +                         dev_name(&pdev->dev), i2c);
> +
> +       if (ret != 0) {
> +               dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq);
> +               goto err_iomap;
> +       }
> +
> +       /* Note, previous versions of the driver used i2c_add_adapter()
> +        * to add the bus at any number. We now pass the bus number via
> +        * the platform data, so if unset it will now default to always
> +        * being bus 0.
> +        */
> +
> +       i2c->adap.nr = pdata->bus_num;
> +
> +       ret = i2c_add_numbered_adapter(&i2c->adap);
> +       if (ret < 0) {
> +               dev_err(&pdev->dev, "failed to add bus to i2c core\n");
> +               goto err_irq;
> +       }
> +
> +       platform_set_drvdata(pdev, i2c);
> +
> +       dev_info(&pdev->dev, "%s: NUC900 I2C adapter\n",
> +                                               dev_name(&i2c->adap.dev));
> +       return 0;
> +
> + err_irq:
> +       free_irq(i2c->irq, i2c);
> +
> + err_iomap:
> +       iounmap(i2c->regs);
> +
> + err_ioarea:
> +       release_resource(i2c->ioarea);
> +       kfree(i2c->ioarea);
> +
> + err_clk:
> +       clk_disable(i2c->clk);
> +       clk_put(i2c->clk);
> +
> + err_noclk:
> +       kfree(i2c);
> +       return ret;
> +}
> +
> +/* nuc900_i2c_remove
> + *
> + * called when device is removed from the bus
> +*/
> +
> +static int __devexit nuc900_i2c_remove(struct platform_device *pdev)
> +{
> +       struct nuc900_i2c *i2c = platform_get_drvdata(pdev);
> +
> +       i2c_del_adapter(&i2c->adap);
> +       free_irq(i2c->irq, i2c);
> +
> +       clk_disable(i2c->clk);
> +       clk_put(i2c->clk);
> +
> +       iounmap(i2c->regs);
> +
> +       release_resource(i2c->ioarea);
> +       kfree(i2c->ioarea);
> +       kfree(i2c);
> +
> +       return 0;
> +}
> +
> +static struct platform_driver nuc900_i2c_driver = {
> +       .probe          = nuc900_i2c_probe,
> +       .remove         = __devexit_p(nuc900_i2c_remove),
> +       .driver         = {
> +               .owner  = THIS_MODULE,
> +               .name   = "nuc900-i2c0",
> +       },
> +};
> +
> +static int __init i2c_adap_nuc900_init(void)
> +{
> +       return platform_driver_register(&nuc900_i2c_driver);
> +}
> +
> +static void __exit i2c_adap_nuc900_exit(void)
> +{
> +       platform_driver_unregister(&nuc900_i2c_driver);
> +}
> +subsys_initcall(i2c_adap_nuc900_init);
> +module_exit(i2c_adap_nuc900_exit);
> +
> +MODULE_DESCRIPTION("NUC900 I2C Bus driver");
> +MODULE_AUTHOR("Wan ZongShun, <mcuos.com@gmail.com>");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:nuc900-i2c0");
> --
> 1.6.3.3
>



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