[PATCH, RFC] Freescale STMP: i2c driver

[PATCH, RFC] Freescale STMP: i2c driver

[dmitry pervushin]

Hello Ben & i2c people,

Here is the patch to support I2C bus on Freescale STMP378x platform; any
comments are welcome

Signed-off-by: Dmitrij Frasenyak <d.frasenyak-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
Signed-off-by: dmitry pervishin <dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>

---
 drivers/i2c/busses/Kconfig        |    7 
 drivers/i2c/busses/Makefile       |    1 
 drivers/i2c/busses/i2c-stmp378x.c |  440 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 448 insertions(+)

Index: linux-2.6-arm/drivers/i2c/busses/Kconfig
===================================================================
--- linux-2.6-arm.orig/drivers/i2c/busses/Kconfig
+++ linux-2.6-arm/drivers/i2c/busses/Kconfig
@@ -513,6 +513,13 @@ config I2C_SIMTEC
 	  This driver can also be built as a module. If so, the module
 	  will be called i2c-simtec.
 
+config I2C_STMP378X
+	tristate "STMP378x I2C adapter"
+	depends on ARCH_STMP378X
+	help
+	  Include support of I2C adapter on Freescale STMP378x board; to build
+	  the driver as a module, say M here - module will be called i2c-stmp378x.
+
 config I2C_VERSATILE
 	tristate "ARM Versatile/Realview I2C bus support"
 	depends on ARCH_VERSATILE || ARCH_REALVIEW
Index: linux-2.6-arm/drivers/i2c/busses/Makefile
===================================================================
--- linux-2.6-arm.orig/drivers/i2c/busses/Makefile
+++ linux-2.6-arm/drivers/i2c/busses/Makefile
@@ -48,6 +48,7 @@ obj-$(CONFIG_I2C_S6000)		+= i2c-s6000.o
 obj-$(CONFIG_I2C_SH7760)	+= i2c-sh7760.o
 obj-$(CONFIG_I2C_SH_MOBILE)	+= i2c-sh_mobile.o
 obj-$(CONFIG_I2C_SIMTEC)	+= i2c-simtec.o
+obj-$(CONFIG_I2C_STMP378X)	+= i2c-stmp378x.o
 obj-$(CONFIG_I2C_VERSATILE)	+= i2c-versatile.o
 
 # External I2C/SMBus adapter drivers
Index: linux-2.6-arm/drivers/i2c/busses/i2c-stmp378x.c
===================================================================
--- /dev/null
+++ linux-2.6-arm/drivers/i2c/busses/i2c-stmp378x.c
@@ -0,0 +1,440 @@
+/*
+ * Freescale STMP378X I2C bus driver
+ *
+ * Author: Dmitrij Frasenyak <sed-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
+ *
+ * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/completion.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
+
+#include <mach/platform.h>
+#include <mach/stmp3xxx.h>
+#include <mach/dma.h>
+#include <mach/regs-i2c.h>
+#include <mach/regs-apbx.h>
+
+static const u32 I2C_READ = 1,
+		 I2C_WRITE = 0;
+
+static const struct stmp3xxx_dma_command cmd_i2c_select = {
+	.cmd =	BF(1, APBX_CHn_CMD_XFER_COUNT)	|
+		BF(1, APBX_CHn_CMD_CMDWORDS)	|
+		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
+		BM_APBX_CHn_CMD_CHAIN		|
+		BF(BV_APBX_CHn_CMD_COMMAND__DMA_READ, APBX_CHn_CMD_COMMAND),
+	.pio_words = {
+		[0] = 	BM_I2C_CTRL0_RETAIN_CLOCK   |
+			BM_I2C_CTRL0_PRE_SEND_START |
+			BM_I2C_CTRL0_MASTER_MODE    |
+			BM_I2C_CTRL0_DIRECTION      |
+			BF(1, I2C_CTRL0_XFER_COUNT),
+	},
+};
+
+static const struct stmp3xxx_dma_command cmd_i2c_write = {
+	.cmd =	BM_APBX_CHn_CMD_SEMAPHORE	|
+		BF(1, APBX_CHn_CMD_CMDWORDS)	|
+		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
+		BM_APBX_CHn_CMD_IRQONCMPLT	|
+		BF(BV_APBX_CHn_CMD_COMMAND__DMA_READ, APBX_CHn_CMD_COMMAND),
+	.pio_words = {
+		[0] =	BM_I2C_CTRL0_PRE_SEND_START |
+			BM_I2C_CTRL0_MASTER_MODE    |
+			BM_I2C_CTRL0_DIRECTION,
+	},
+};
+
+static const struct stmp3xxx_dma_command cmd_i2c_read = {
+	.cmd =	BM_APBX_CHn_CMD_SEMAPHORE	|
+		BF(1, APBX_CHn_CMD_CMDWORDS)	|
+		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
+		BM_APBX_CHn_CMD_IRQONCMPLT	|
+		BF(BV_APBX_CHn_CMD_COMMAND__DMA_WRITE, APBX_CHn_CMD_COMMAND),
+	.pio_words = {
+		[0] =	BM_I2C_CTRL0_SEND_NAK_ON_LAST	|
+			BM_I2C_CTRL0_MASTER_MODE,
+	},
+};
+
+struct stmp378x_i2c_dev {
+	struct device		*dev;
+	int			irq;
+	struct completion	cmd_complete;
+	u32			cmd_err;
+	struct i2c_adapter	adapter;
+	void __iomem 		*io;
+	unsigned		dma;
+
+	dma_addr_t		bufp;
+	unsigned char		*bufv;
+
+	struct stmp3xxx_dma_descriptor i2c_dma_read[2],
+				       i2c_dma_write;
+};
+
+static int stmp378x_i2c_init(struct stmp378x_i2c_dev *dev)
+{
+	int err;
+
+	err = stmp3xxx_dma_request(dev->dma, dev->dev, dev_name(dev->dev));
+	if (err)
+		goto out;
+	stmp3xxx_reset_block(dev->io, true);
+
+	dev->bufv = dma_alloc_coherent(dev->dev, PAGE_SIZE,
+				       &dev->bufp, GFP_KERNEL);
+	if (dma_mapping_error(dev->dev, dev->bufp))
+		goto out_dma;
+
+	err = stmp3xxx_request_pin_group(dev->dev->platform_data,
+			dev_name(dev->dev));
+	if (err)
+		goto out_free;
+
+	err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_read[0]);
+	if (err)
+		goto out_rd0;
+	err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_read[1]);
+	if (err)
+		goto out_rd1;
+	err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_write);
+	if (err)
+		goto out_wr;
+
+	stmp3xxx_dma_reset_channel(dev->dma);
+	stmp3xxx_dma_clear_interrupt(dev->dma);
+	stmp3xxx_dma_enable_interrupt(dev->dma);
+
+	return 0;
+/*
+	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_write);
+*/
+out_wr:
+	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[1]);
+out_rd1:
+	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[0]);
+out_rd0:
+	stmp3xxx_release_pin_group(dev->dev->platform_data, dev_name(dev->dev));
+out_free:
+	dma_free_coherent(dev->dev, PAGE_SIZE, dev->bufv, dev->bufp);
+out_dma:
+	stmp3xxx_dma_release(dev->dma);
+out:
+	return err;
+}
+
+static void stmp378x_i2c_release(struct stmp378x_i2c_dev *dev)
+{
+	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_write);
+	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[1]);
+	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[0]);
+	dma_free_coherent(dev->dev, PAGE_SIZE, dev->bufv, dev->bufp);
+	stmp3xxx_release_pin_group(dev->dev->platform_data, dev_name(dev->dev));
+	stmp3xxx_dma_release(dev->dma);
+}
+/*
+ * Low level master read/write transaction.
+ */
+static int stmp378x_i2c_xfer_msg(struct i2c_adapter *adap,
+				 struct i2c_msg *msg, int stop)
+{
+	struct stmp378x_i2c_dev *dev = i2c_get_adapdata(adap);
+	int err;
+	struct stmp3xxx_dma_descriptor *c, *r;
+
+	init_completion(&dev->cmd_complete);
+	dev->cmd_err = 0;
+
+	dev_dbg(dev->dev, "start XFER\n");
+	dev_dbg(dev->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
+		msg->addr, msg->len, msg->flags, stop);
+
+	if ((msg->len == 0) || (msg->len > (PAGE_SIZE - 1)))
+		return -EINVAL;
+
+	if (msg->flags & I2C_M_RD) {
+
+		c = &dev->i2c_dma_read[0];
+		r = &dev->i2c_dma_read[1];
+
+		/* first, setup the SELECT command */
+		memcpy(c->command, &cmd_i2c_select, sizeof(cmd_i2c_select));
+		c->command->buf_ptr = dev->bufp;
+		dev->bufv[0] = msg->addr | I2C_READ;
+
+		/* then, setup the READ command */
+		memcpy(r->command, &cmd_i2c_read, sizeof(cmd_i2c_read));
+		r->command->cmd |= BF(msg->len, APBX_CHn_CMD_XFER_COUNT);
+		r->command->pio_words[0] |= BF(msg->len, I2C_CTRL0_XFER_COUNT);
+		if (stop)
+			r->command->pio_words[0] |= BM_I2C_CTRL0_POST_SEND_STOP;
+		/*
+		 * yes, STMP controller can DMA transfer the data from any
+		 * byte boundary
+		 */
+		r->command->buf_ptr = dev->bufp + 1;
+
+		/* and chain them together */
+		c->command->next = r->handle;
+
+	} else {
+
+		c = &dev->i2c_dma_write;
+		memcpy(c->command, &cmd_i2c_write, sizeof(cmd_i2c_write));
+		c->command->cmd |= BF(msg->len + 1, APBX_CHn_CMD_XFER_COUNT);
+		c->command->pio_words[0] |=
+				   BF(msg->len + 1, I2C_CTRL0_XFER_COUNT);
+		if (stop)
+			c->command->pio_words[0] |=
+				   BM_I2C_CTRL0_POST_SEND_STOP;
+		dev->bufv[0] = msg->addr | I2C_WRITE;
+		memcpy(dev->bufv + 1, msg->buf, msg->len);
+	}
+
+	stmp3xxx_dma_go(dev->dma, c, 1);
+
+	err = wait_for_completion_interruptible_timeout(&dev->cmd_complete,
+							msecs_to_jiffies(1000));
+
+	if (err < 0) {
+		dev_dbg(dev->dev, "controler is timed out\n");
+		return -ETIMEDOUT;
+	}
+	if (!dev->cmd_err && (msg->flags & I2C_M_RD))
+		memcpy(msg->buf, dev->bufv + 1, msg->len);
+
+	dev_dbg(dev->dev, "done with err=%d\n", dev->cmd_err);
+
+	return dev->cmd_err;
+}
+
+
+static int
+stmp378x_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
+{
+	int i;
+	int err;
+
+	if (!msgs->len)
+		return -EINVAL;
+
+	for (i = 0; i < num; i++) {
+		err = stmp378x_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
+		if (err)
+			return err;
+	}
+	return num;
+}
+
+static u32
+stmp378x_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+}
+
+#define I2C_IRQ_MASK 0x000000FF
+static irqreturn_t
+stmp378x_i2c_isr(int this_irq, void *dev_id)
+{
+	struct stmp378x_i2c_dev *dev = dev_id;
+	u32 stat;
+	u32 done_mask = BM_I2C_CTRL1_DATA_ENGINE_CMPLT_IRQ |
+			BM_I2C_CTRL1_BUS_FREE_IRQ ;
+
+	stat = readl(HW_I2C_CTRL1 + dev->io) & I2C_IRQ_MASK;
+	if (!stat)
+		return IRQ_NONE;
+
+	if (stat & BM_I2C_CTRL1_NO_SLAVE_ACK_IRQ) {
+		dev->cmd_err = -EREMOTEIO;
+
+		/*
+		 * Stop DMA
+		 * Clear NAK
+		 */
+		stmp3xxx_setl(BM_I2C_CTRL1_CLR_GOT_A_NAK,
+			      HW_I2C_CTRL1 + dev->io);
+		stmp3xxx_dma_reset_channel(dev->dma);
+		stmp3xxx_dma_clear_interrupt(dev->dma);
+
+		complete(&dev->cmd_complete);
+
+		goto done;
+	}
+
+	/* Don't care about  BM_I2C_CTRL1_OVERSIZE_XFER_TERM_IRQ */
+	if (stat & (BM_I2C_CTRL1_EARLY_TERM_IRQ |
+		    BM_I2C_CTRL1_MASTER_LOSS_IRQ |
+		    BM_I2C_CTRL1_SLAVE_STOP_IRQ |
+		    BM_I2C_CTRL1_SLAVE_IRQ)) {
+		dev->cmd_err = -EIO;
+		complete(&dev->cmd_complete);
+		goto done;
+	}
+
+	if ((stat & done_mask) == done_mask)
+		complete(&dev->cmd_complete);
+
+done:
+	stmp3xxx_clearl(stat, dev->io + HW_I2C_CTRL1);
+	return IRQ_HANDLED;
+}
+
+static const struct i2c_algorithm stmp378x_i2c_algo = {
+	.master_xfer	= stmp378x_i2c_xfer,
+	.functionality	= stmp378x_i2c_func,
+};
+
+
+static int __devinit
+stmp378x_i2c_probe(struct platform_device *pdev)
+{
+	struct stmp378x_i2c_dev	*dev;
+	struct i2c_adapter	*adap;
+	struct resource		*mem, *dma;
+	int err = 0;
+
+	/* NOTE: driver uses the static register mapping */
+	dev = kzalloc(sizeof(struct stmp378x_i2c_dev), GFP_KERNEL);
+	if (!dev) {
+		dev_err(&pdev->dev, "no mem \n");
+		return -ENOMEM;
+	}
+
+	dev->irq = platform_get_irq(pdev, 0); /* Error */
+	if (dev->irq < 0) {
+		dev_err(&pdev->dev, "no err_irq resource\n");
+		err = -ENODEV;
+		goto nores;
+	}
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mem) {
+		dev_err(&pdev->dev, "no memory window\n");
+		err = -ENODEV;
+		goto nores;
+	}
+
+	dma = platform_get_resource(pdev, IORESOURCE_DMA, 0);
+	if (!dma) {
+		dev_err(&pdev->dev, "no dma channel\n");
+		err = -ENODEV;
+		goto nores;
+	}
+	dev->dma = dma->start;
+
+	dev->dev = &pdev->dev;
+	dev->io = ioremap(mem->start, resource_size(mem));
+	if (!dev->io) {
+		dev_err(&pdev->dev, "cannot ioremap\n");
+		err = -ENXIO;
+		goto nores;
+	}
+
+	err = request_irq(dev->irq, stmp378x_i2c_isr, 0, pdev->name, dev);
+	if (err) {
+		dev_err(&pdev->dev, "Can't get IRQ\n");
+		goto no_err_irq;
+	}
+
+	err = stmp378x_i2c_init(dev);
+	if (err) {
+		dev_err(&pdev->dev, "HW Init failed\n");
+		goto init_failed;
+	}
+
+	stmp3xxx_setl(0xFF00, dev->io + HW_I2C_CTRL1);
+
+	adap = &dev->adapter;
+	i2c_set_adapdata(adap, dev);
+	adap->owner = THIS_MODULE;
+	adap->class = I2C_CLASS_HWMON;
+	strncpy(adap->name, "378x I2C adapter", sizeof(adap->name));
+	adap->algo = &stmp378x_i2c_algo;
+	adap->dev.parent = &pdev->dev;
+
+	adap->nr = pdev->id;
+	err = i2c_add_numbered_adapter(adap);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to add adapter\n");
+		goto no_i2c_adapter;
+
+	}
+
+	return 0;
+
+no_i2c_adapter:
+	stmp378x_i2c_release(dev);
+init_failed:
+	free_irq(dev->irq, dev);
+no_err_irq:
+	iounmap(dev->io);
+nores:
+	kfree(dev);
+	return err;
+}
+
+static int __devexit
+stmp378x_i2c_remove(struct platform_device *pdev)
+{
+	struct stmp378x_i2c_dev	*dev = platform_get_drvdata(pdev);
+	int res;
+
+	res = i2c_del_adapter(&dev->adapter);
+	if (res)
+		return -EBUSY;
+
+	stmp378x_i2c_release(dev);
+
+	platform_set_drvdata(pdev, NULL);
+
+	free_irq(dev->irq, dev);
+	iounmap(dev->io);
+
+	kfree(dev);
+	return 0;
+}
+
+static struct platform_driver stmp378x_i2c_driver = {
+	.probe		= stmp378x_i2c_probe,
+	.remove		= __devexit_p(stmp378x_i2c_remove),
+	.driver		= {
+		.name	= "i2c_stmp",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init stmp378x_i2c_init_driver(void)
+{
+	return platform_driver_register(&stmp378x_i2c_driver);
+}
+module_init(stmp378x_i2c_init_driver);
+
+static void __exit stmp378x_i2c_exit_driver(void)
+{
+	platform_driver_unregister(&stmp378x_i2c_driver);
+}
+module_exit(stmp378x_i2c_exit_driver);
+
+MODULE_AUTHOR("d.frasenyak-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org");
+MODULE_DESCRIPTION("I2C for Freescale STMP378x");
+MODULE_LICENSE("GPL");

Re: [PATCH, RFC] Freescale STMP: i2c driver

[Ben Dooks]

On Wed, Jun 03, 2009 at 11:59:15PM +0400, dmitry pervushin wrote:
> Hello Ben & i2c people,
> 
> Here is the patch to support I2C bus on Freescale STMP378x platform; any
> comments are welcome
> 
> Signed-off-by: Dmitrij Frasenyak <d.frasenyak-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>

should really have a from Dmitrij Frasenyak line as he is the original
authour and you're just pushing it, IIRC.

> Signed-off-by: dmitry pervishin <dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
> 
> ---
>  drivers/i2c/busses/Kconfig        |    7 
>  drivers/i2c/busses/Makefile       |    1 
>  drivers/i2c/busses/i2c-stmp378x.c |  440 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 448 insertions(+)
> 
> Index: linux-2.6-arm/drivers/i2c/busses/Kconfig
> ===================================================================
> --- linux-2.6-arm.orig/drivers/i2c/busses/Kconfig
> +++ linux-2.6-arm/drivers/i2c/busses/Kconfig
> @@ -513,6 +513,13 @@ config I2C_SIMTEC
>  	  This driver can also be built as a module. If so, the module
>  	  will be called i2c-simtec.
>  
> +config I2C_STMP378X
> +	tristate "STMP378x I2C adapter"
> +	depends on ARCH_STMP378X
> +	help
> +	  Include support of I2C adapter on Freescale STMP378x board; to build
> +	  the driver as a module, say M here - module will be called i2c-stmp378x.
> +
>  config I2C_VERSATILE
>  	tristate "ARM Versatile/Realview I2C bus support"
>  	depends on ARCH_VERSATILE || ARCH_REALVIEW
> Index: linux-2.6-arm/drivers/i2c/busses/Makefile
> ===================================================================
> --- linux-2.6-arm.orig/drivers/i2c/busses/Makefile
> +++ linux-2.6-arm/drivers/i2c/busses/Makefile
> @@ -48,6 +48,7 @@ obj-$(CONFIG_I2C_S6000)		+= i2c-s6000.o
>  obj-$(CONFIG_I2C_SH7760)	+= i2c-sh7760.o
>  obj-$(CONFIG_I2C_SH_MOBILE)	+= i2c-sh_mobile.o
>  obj-$(CONFIG_I2C_SIMTEC)	+= i2c-simtec.o
> +obj-$(CONFIG_I2C_STMP378X)	+= i2c-stmp378x.o
>  obj-$(CONFIG_I2C_VERSATILE)	+= i2c-versatile.o
>  
>  # External I2C/SMBus adapter drivers
> Index: linux-2.6-arm/drivers/i2c/busses/i2c-stmp378x.c
> ===================================================================
> --- /dev/null
> +++ linux-2.6-arm/drivers/i2c/busses/i2c-stmp378x.c
> @@ -0,0 +1,440 @@
> +/*
> + * Freescale STMP378X I2C bus driver
> + *
> + * Author: Dmitrij Frasenyak <sed-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
> + *
> + * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
> + * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
> + */
> +
> +/*
> + * The code contained herein is licensed under the GNU General Public
> + * License. You may obtain a copy of the GNU General Public License
> + * Version 2 or later at the following locations:
> + *
> + * http://www.opensource.org/licenses/gpl-license.html
> + * http://www.gnu.org/copyleft/gpl.html
> + */
> +#include <linux/module.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/err.h>
> +#include <linux/interrupt.h>
> +#include <linux/completion.h>
> +#include <linux/platform_device.h>
> +#include <linux/clk.h>
> +#include <linux/io.h>
> +#include <linux/dma-mapping.h>
> +
> +#include <mach/platform.h>
> +#include <mach/stmp3xxx.h>
> +#include <mach/dma.h>
> +#include <mach/regs-i2c.h>
> +#include <mach/regs-apbx.h>
> +
> +static const u32 I2C_READ = 1,
> +		 I2C_WRITE = 0;

do you really want to be defining things with a prefix of I2C, that
might end up clashing with the i2c core?

> +static const struct stmp3xxx_dma_command cmd_i2c_select = {
> +	.cmd =	BF(1, APBX_CHn_CMD_XFER_COUNT)	|
> +		BF(1, APBX_CHn_CMD_CMDWORDS)	|
> +		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
> +		BM_APBX_CHn_CMD_CHAIN		|
> +		BF(BV_APBX_CHn_CMD_COMMAND__DMA_READ, APBX_CHn_CMD_COMMAND),

what is BF() ?

> +	.pio_words = {
> +		[0] = 	BM_I2C_CTRL0_RETAIN_CLOCK   |
> +			BM_I2C_CTRL0_PRE_SEND_START |
> +			BM_I2C_CTRL0_MASTER_MODE    |
> +			BM_I2C_CTRL0_DIRECTION      |
> +			BF(1, I2C_CTRL0_XFER_COUNT),
> +	},
> +};
> +
> +static const struct stmp3xxx_dma_command cmd_i2c_write = {
> +	.cmd =	BM_APBX_CHn_CMD_SEMAPHORE	|
> +		BF(1, APBX_CHn_CMD_CMDWORDS)	|
> +		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
> +		BM_APBX_CHn_CMD_IRQONCMPLT	|
> +		BF(BV_APBX_CHn_CMD_COMMAND__DMA_READ, APBX_CHn_CMD_COMMAND),
> +	.pio_words = {
> +		[0] =	BM_I2C_CTRL0_PRE_SEND_START |
> +			BM_I2C_CTRL0_MASTER_MODE    |
> +			BM_I2C_CTRL0_DIRECTION,
> +	},
> +};
> +
> +static const struct stmp3xxx_dma_command cmd_i2c_read = {
> +	.cmd =	BM_APBX_CHn_CMD_SEMAPHORE	|
> +		BF(1, APBX_CHn_CMD_CMDWORDS)	|
> +		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
> +		BM_APBX_CHn_CMD_IRQONCMPLT	|
> +		BF(BV_APBX_CHn_CMD_COMMAND__DMA_WRITE, APBX_CHn_CMD_COMMAND),
> +	.pio_words = {
> +		[0] =	BM_I2C_CTRL0_SEND_NAK_ON_LAST	|
> +			BM_I2C_CTRL0_MASTER_MODE,
> +	},
> +};
> +
> +struct stmp378x_i2c_dev {
> +	struct device		*dev;
> +	int			irq;
> +	struct completion	cmd_complete;
> +	u32			cmd_err;
> +	struct i2c_adapter	adapter;
> +	void __iomem 		*io;
> +	unsigned		dma;
> +
> +	dma_addr_t		bufp;
> +	unsigned char		*bufv;
> +
> +	struct stmp3xxx_dma_descriptor i2c_dma_read[2],
> +				       i2c_dma_write;
> +};

would be nice to see some kerneldoc descriptions for the fields in
this structure.

> +static int stmp378x_i2c_init(struct stmp378x_i2c_dev *dev)
> +{
> +	int err;
> +
> +	err = stmp3xxx_dma_request(dev->dma, dev->dev, dev_name(dev->dev));
> +	if (err)
> +		goto out;
> +	stmp3xxx_reset_block(dev->io, true);
> +
> +	dev->bufv = dma_alloc_coherent(dev->dev, PAGE_SIZE,
> +				       &dev->bufp, GFP_KERNEL);
> +	if (dma_mapping_error(dev->dev, dev->bufp))
> +		goto out_dma;

hmm, doesn't dma_alloc_coherent() fail with an NULL buffer return?

> +	err = stmp3xxx_request_pin_group(dev->dev->platform_data,
> +			dev_name(dev->dev));
> +	if (err)
> +		goto out_free;
> +
> +	err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_read[0]);
> +	if (err)
> +		goto out_rd0;
> +	err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_read[1]);
> +	if (err)
> +		goto out_rd1;
> +	err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_write);
> +	if (err)
> +		goto out_wr;
> +
> +	stmp3xxx_dma_reset_channel(dev->dma);
> +	stmp3xxx_dma_clear_interrupt(dev->dma);
> +	stmp3xxx_dma_enable_interrupt(dev->dma);
> +
> +	return 0;
> +/*
> +	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_write);
> +*/
> +out_wr:
> +	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[1]);
> +out_rd1:
> +	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[0]);
> +out_rd0:
> +	stmp3xxx_release_pin_group(dev->dev->platform_data, dev_name(dev->dev));
> +out_free:
> +	dma_free_coherent(dev->dev, PAGE_SIZE, dev->bufv, dev->bufp);
> +out_dma:
> +	stmp3xxx_dma_release(dev->dma);
> +out:
> +	return err;
> +}
> +
> +static void stmp378x_i2c_release(struct stmp378x_i2c_dev *dev)
> +{
> +	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_write);
> +	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[1]);
> +	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[0]);
> +	dma_free_coherent(dev->dev, PAGE_SIZE, dev->bufv, dev->bufp);
> +	stmp3xxx_release_pin_group(dev->dev->platform_data, dev_name(dev->dev));
> +	stmp3xxx_dma_release(dev->dma);
> +}
> +/*
> + * Low level master read/write transaction.
> + */
> +static int stmp378x_i2c_xfer_msg(struct i2c_adapter *adap,
> +				 struct i2c_msg *msg, int stop)
> +{
> +	struct stmp378x_i2c_dev *dev = i2c_get_adapdata(adap);
> +	int err;
> +	struct stmp3xxx_dma_descriptor *c, *r;
> +
> +	init_completion(&dev->cmd_complete);
> +	dev->cmd_err = 0;
> +
> +	dev_dbg(dev->dev, "start XFER\n");
> +	dev_dbg(dev->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
> +		msg->addr, msg->len, msg->flags, stop);
> +
> +	if ((msg->len == 0) || (msg->len > (PAGE_SIZE - 1)))
> +		return -EINVAL;
> +
> +	if (msg->flags & I2C_M_RD) {
> +
> +		c = &dev->i2c_dma_read[0];
> +		r = &dev->i2c_dma_read[1];
> +
> +		/* first, setup the SELECT command */
> +		memcpy(c->command, &cmd_i2c_select, sizeof(cmd_i2c_select));
> +		c->command->buf_ptr = dev->bufp;
> +		dev->bufv[0] = msg->addr | I2C_READ;
> +
> +		/* then, setup the READ command */
> +		memcpy(r->command, &cmd_i2c_read, sizeof(cmd_i2c_read));
> +		r->command->cmd |= BF(msg->len, APBX_CHn_CMD_XFER_COUNT);
> +		r->command->pio_words[0] |= BF(msg->len, I2C_CTRL0_XFER_COUNT);
> +		if (stop)
> +			r->command->pio_words[0] |= BM_I2C_CTRL0_POST_SEND_STOP;
> +		/*
> +		 * yes, STMP controller can DMA transfer the data from any
> +		 * byte boundary
> +		 */
> +		r->command->buf_ptr = dev->bufp + 1;
> +
> +		/* and chain them together */
> +		c->command->next = r->handle;
> +
> +	} else {
> +
> +		c = &dev->i2c_dma_write;
> +		memcpy(c->command, &cmd_i2c_write, sizeof(cmd_i2c_write));
> +		c->command->cmd |= BF(msg->len + 1, APBX_CHn_CMD_XFER_COUNT);
> +		c->command->pio_words[0] |=
> +				   BF(msg->len + 1, I2C_CTRL0_XFER_COUNT);
> +		if (stop)
> +			c->command->pio_words[0] |=
> +				   BM_I2C_CTRL0_POST_SEND_STOP;
> +		dev->bufv[0] = msg->addr | I2C_WRITE;
> +		memcpy(dev->bufv + 1, msg->buf, msg->len);
> +	}
> +
> +	stmp3xxx_dma_go(dev->dma, c, 1);
> +
> +	err = wait_for_completion_interruptible_timeout(&dev->cmd_complete,
> +							msecs_to_jiffies(1000));
> +
> +	if (err < 0) {
> +		dev_dbg(dev->dev, "controler is timed out\n");
> +		return -ETIMEDOUT;
> +	}
> +	if (!dev->cmd_err && (msg->flags & I2C_M_RD))
> +		memcpy(msg->buf, dev->bufv + 1, msg->len);
> +
> +	dev_dbg(dev->dev, "done with err=%d\n", dev->cmd_err);
> +
> +	return dev->cmd_err;
> +}
> +
> +
> +static int
> +stmp378x_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
> +{
> +	int i;
> +	int err;
> +
> +	if (!msgs->len)
> +		return -EINVAL;
> +
> +	for (i = 0; i < num; i++) {
> +		err = stmp378x_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
> +		if (err)
> +			return err;
> +	}
> +	return num;
> +}
> +
> +static u32
> +stmp378x_i2c_func(struct i2c_adapter *adap)
> +{
> +	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
> +}
> +
> +#define I2C_IRQ_MASK 0x000000FF
> +static irqreturn_t
> +stmp378x_i2c_isr(int this_irq, void *dev_id)
> +{
> +	struct stmp378x_i2c_dev *dev = dev_id;
> +	u32 stat;
> +	u32 done_mask = BM_I2C_CTRL1_DATA_ENGINE_CMPLT_IRQ |
> +			BM_I2C_CTRL1_BUS_FREE_IRQ ;
> +
> +	stat = readl(HW_I2C_CTRL1 + dev->io) & I2C_IRQ_MASK;
> +	if (!stat)
> +		return IRQ_NONE;
> +
> +	if (stat & BM_I2C_CTRL1_NO_SLAVE_ACK_IRQ) {
> +		dev->cmd_err = -EREMOTEIO;
> +
> +		/*
> +		 * Stop DMA
> +		 * Clear NAK
> +		 */
> +		stmp3xxx_setl(BM_I2C_CTRL1_CLR_GOT_A_NAK,
> +			      HW_I2C_CTRL1 + dev->io);
> +		stmp3xxx_dma_reset_channel(dev->dma);
> +		stmp3xxx_dma_clear_interrupt(dev->dma);
> +
> +		complete(&dev->cmd_complete);
> +
> +		goto done;
> +	}
> +
> +	/* Don't care about  BM_I2C_CTRL1_OVERSIZE_XFER_TERM_IRQ */
> +	if (stat & (BM_I2C_CTRL1_EARLY_TERM_IRQ |
> +		    BM_I2C_CTRL1_MASTER_LOSS_IRQ |
> +		    BM_I2C_CTRL1_SLAVE_STOP_IRQ |
> +		    BM_I2C_CTRL1_SLAVE_IRQ)) {
> +		dev->cmd_err = -EIO;
> +		complete(&dev->cmd_complete);
> +		goto done;
> +	}
> +
> +	if ((stat & done_mask) == done_mask)
> +		complete(&dev->cmd_complete);
> +
> +done:
> +	stmp3xxx_clearl(stat, dev->io + HW_I2C_CTRL1);
> +	return IRQ_HANDLED;
> +}
> +
> +static const struct i2c_algorithm stmp378x_i2c_algo = {
> +	.master_xfer	= stmp378x_i2c_xfer,
> +	.functionality	= stmp378x_i2c_func,
> +};
> +
> +
> +static int __devinit
> +stmp378x_i2c_probe(struct platform_device *pdev)
> +{
> +	struct stmp378x_i2c_dev	*dev;
> +	struct i2c_adapter	*adap;
> +	struct resource		*mem, *dma;
> +	int err = 0;
> +
> +	/* NOTE: driver uses the static register mapping */
> +	dev = kzalloc(sizeof(struct stmp378x_i2c_dev), GFP_KERNEL);
> +	if (!dev) {
> +		dev_err(&pdev->dev, "no mem \n");
> +		return -ENOMEM;
> +	}
> +
> +	dev->irq = platform_get_irq(pdev, 0); /* Error */
> +	if (dev->irq < 0) {
> +		dev_err(&pdev->dev, "no err_irq resource\n");
> +		err = -ENODEV;
> +		goto nores;
> +	}

-ENODEV isn't what you want here, you'll end up losing errors in the
higher level.

> +	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!mem) {
> +		dev_err(&pdev->dev, "no memory window\n");
> +		err = -ENODEV;
> +		goto nores;
> +	}
> +
> +	dma = platform_get_resource(pdev, IORESOURCE_DMA, 0);
> +	if (!dma) {
> +		dev_err(&pdev->dev, "no dma channel\n");
> +		err = -ENODEV;
> +		goto nores;
> +	}
> +	dev->dma = dma->start;
> +
> +	dev->dev = &pdev->dev;
> +	dev->io = ioremap(mem->start, resource_size(mem));
> +	if (!dev->io) {
> +		dev_err(&pdev->dev, "cannot ioremap\n");
> +		err = -ENXIO;
> +		goto nores;
> +	}
> +
> +	err = request_irq(dev->irq, stmp378x_i2c_isr, 0, pdev->name, dev);
> +	if (err) {
> +		dev_err(&pdev->dev, "Can't get IRQ\n");
> +		goto no_err_irq;
> +	}
> +
> +	err = stmp378x_i2c_init(dev);
> +	if (err) {
> +		dev_err(&pdev->dev, "HW Init failed\n");
> +		goto init_failed;
> +	}
> +
> +	stmp3xxx_setl(0xFF00, dev->io + HW_I2C_CTRL1);
> +
> +	adap = &dev->adapter;
> +	i2c_set_adapdata(adap, dev);
> +	adap->owner = THIS_MODULE;
> +	adap->class = I2C_CLASS_HWMON;

is this the correct class?

> +	strncpy(adap->name, "378x I2C adapter", sizeof(adap->name));
> +	adap->algo = &stmp378x_i2c_algo;
> +	adap->dev.parent = &pdev->dev;
> +
> +	adap->nr = pdev->id;
> +	err = i2c_add_numbered_adapter(adap);
> +	if (err) {
> +		dev_err(&pdev->dev, "Failed to add adapter\n");
> +		goto no_i2c_adapter;
> +
> +	}
> +
> +	return 0;
> +
> +no_i2c_adapter:
> +	stmp378x_i2c_release(dev);
> +init_failed:
> +	free_irq(dev->irq, dev);
> +no_err_irq:
> +	iounmap(dev->io);
> +nores:
> +	kfree(dev);
> +	return err;
> +}
> +
> +static int __devexit
> +stmp378x_i2c_remove(struct platform_device *pdev)
> +{
> +	struct stmp378x_i2c_dev	*dev = platform_get_drvdata(pdev);
> +	int res;
> +
> +	res = i2c_del_adapter(&dev->adapter);
> +	if (res)
> +		return -EBUSY;
> +
> +	stmp378x_i2c_release(dev);
> +
> +	platform_set_drvdata(pdev, NULL);
> +
> +	free_irq(dev->irq, dev);
> +	iounmap(dev->io);
> +
> +	kfree(dev);
> +	return 0;
> +}
> +
> +static struct platform_driver stmp378x_i2c_driver = {
> +	.probe		= stmp378x_i2c_probe,
> +	.remove		= __devexit_p(stmp378x_i2c_remove),
> +	.driver		= {
> +		.name	= "i2c_stmp",
> +		.owner	= THIS_MODULE,
> +	},
> +};
> +
> +static int __init stmp378x_i2c_init_driver(void)
> +{
> +	return platform_driver_register(&stmp378x_i2c_driver);
> +}
> +module_init(stmp378x_i2c_init_driver);
> +
> +static void __exit stmp378x_i2c_exit_driver(void)
> +{
> +	platform_driver_unregister(&stmp378x_i2c_driver);
> +}
> +module_exit(stmp378x_i2c_exit_driver);
> +
> +MODULE_AUTHOR("d.frasenyak-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org");
> +MODULE_DESCRIPTION("I2C for Freescale STMP378x");
> +MODULE_LICENSE("GPL");

no module alias for autoloading?
 
> 
> --
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> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
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-- 
Ben (ben-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org, http://www.fluff.org/)

  'a smiley only costs 4 bytes'

Re: [PATCH, RFC] Freescale STMP: i2c driver

[Jean Delvare]

On Mon, 8 Jun 2009 23:50:34 +0100, Ben Dooks wrote:
> On Wed, Jun 03, 2009 at 11:59:15PM +0400, dmitry pervushin wrote:
> > +static const u32 I2C_READ = 1,
> > +		 I2C_WRITE = 0;
> 
> do you really want to be defining things with a prefix of I2C, that
> might end up clashing with the i2c core?

Definitely not. Please just use I2C_SMBUS_READ and I2C_SMBUS_WRITE
which are already defined by <linux/i2c.h>.

(One might argue these are unfortunate names, but that's what we have
at the moment so let's just use it.)

-- 
Jean Delvare

Re: [PATCH, RFC] Freescale STMP: i2c driver

[dmitry pervushin]

Hello Ben,

I am sending the updated patch in next message, and this message is just
to answer your questions/concerns.\

[...]
> > +#include <mach/regs-apbx.h>
> > +
> > +static const u32 I2C_READ = 1,
> > +		 I2C_WRITE = 0;
> 
> do you really want to be defining things with a prefix of I2C, thatB
> might end up clashing with the i2c core?
Fixed, changed to I2C_SMBUS_READ/WRITE as Jean Delvare proposed.
> 
> > +static const struct stmp3xxx_dma_command cmd_i2c_select = {
> > +	.cmd =	BF(1, APBX_CHn_CMD_XFER_COUNT)	|
> > +		BF(1, APBX_CHn_CMD_CMDWORDS)	|
> > +		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
> > +		BM_APBX_CHn_CMD_CHAIN		|
> > +		BF(BV_APBX_CHn_CMD_COMMAND__DMA_READ, APBX_CHn_CMD_COMMAND),
> 
> what is BF() ?
it is the macro from arch/arm/plat-stmp3xxx/include/mach/platform.h,
abbreviated "bitfield" :) For example, BF(1, APBX_CHn_CMD_CMDWORDS) is
expanded like 
((1 << BP_APBX_CHn_CMD_CMDWORDS) & BM_APBX_CHn_CMD_CMDWORDS).
BP_xxx stuff means bitfield position, BM_xxx - bitfield mask. 

>> +     dev->bufv = dma_alloc_coherent(dev->dev, PAGE_SIZE,
>> +                                    &dev->bufp, GFP_KERNEL);>
>> +     if (dma_mapping_error(dev->dev, dev->bufp))
>> +             goto out_dma;
> hmm, doesn't dma_alloc_coherent() fail with an NULL buffer return?
Fixed; but using dma_mapping_error seems to be more accurate method to
me. 0 might be valid dma address on some architecture. Again, for the
time being there is no difference to check dma_mapping_error or plain
compare with NULL...

[skipped]
> > +	adap = &dev->adapter;
> > +	i2c_set_adapdata(adap, dev);
> > +	adap->owner = THIS_MODULE;
> > +	adap->class = I2C_CLASS_HWMON;
> 
> is this the correct class?
Mmm.. I changed this to I2C_CLASS_TV_DIGITAL since the only I2C user is
digital radio daughterboard. Any objections?
> 
> > +	strncpy(adap->name, "378x I2C adapter", sizeof(adap->name));
> > +	adap->algo = &stmp378x_i2c_algo;
> > +	adap->dev.parent = &pdev->dev;
> > +
> > +	adap->nr = pdev->id;
> > +	err = i2c_add_numbered_adapter(adap);
> > +	if (err) {
> > +		dev_err(&pdev->dev, "Failed to add adapter\n");
> > +		goto no_i2c_adapter;
> > +
> > +	}
> > +
> > +	return 0;
> > +
> > +no_i2c_adapter:
> > +	stmp378x_i2c_release(dev);
> > +init_failed:
> > +	free_irq(dev->irq, dev);
> > +no_err_irq:
> > +	iounmap(dev->io);
> > +nores:
> > +	kfree(dev);
> > +	return err;
> > +}
> > +
> > +static int __devexit
> > +stmp378x_i2c_remove(struct platform_device *pdev)
> > +{
> > +	struct stmp378x_i2c_dev	*dev = platform_get_drvdata(pdev);
> > +	int res;
> > +
> > +	res = i2c_del_adapter(&dev->adapter);
> > +	if (res)
> > +		return -EBUSY;
> > +
> > +	stmp378x_i2c_release(dev);
> > +
> > +	platform_set_drvdata(pdev, NULL);
> > +
> > +	free_irq(dev->irq, dev);
> > +	iounmap(dev->io);
> > +
> > +	kfree(dev);
> > +	return 0;
> > +}
> > +
> > +static struct platform_driver stmp378x_i2c_driver = {
> > +	.probe		= stmp378x_i2c_probe,
> > +	.remove		= __devexit_p(stmp378x_i2c_remove),
> > +	.driver		= {
> > +		.name	= "i2c_stmp",
> > +		.owner	= THIS_MODULE,
> > +	},
> > +};
> > +
> > +static int __init stmp378x_i2c_init_driver(void)
> > +{
> > +	return platform_driver_register(&stmp378x_i2c_driver);
> > +}
> > +module_init(stmp378x_i2c_init_driver);
> > +
> > +static void __exit stmp378x_i2c_exit_driver(void)
> > +{
> > +	platform_driver_unregister(&stmp378x_i2c_driver);
> > +}
> > +module_exit(stmp378x_i2c_exit_driver);
> > +
> > +MODULE_AUTHOR("d.frasenyak-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org");
> > +MODULE_DESCRIPTION("I2C for Freescale STMP378x");
> > +MODULE_LICENSE("GPL");
> 
> no module alias for autoloading?
Added.
> > 
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
> > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
	

Re: [PATCH, RFC] Freescale STMP: i2c driver

[Ben Dooks]

On Tue, Jun 16, 2009 at 08:25:39PM +0400, dmitry pervushin wrote:
> Hello Ben,
> 
> I am sending the updated patch in next message, and this message is just
> to answer your questions/concerns.\
> 
> [...]
> > > +#include <mach/regs-apbx.h>
> > > +
> > > +static const u32 I2C_READ = 1,
> > > +		 I2C_WRITE = 0;
> > 
> > do you really want to be defining things with a prefix of I2C, thatB
> > might end up clashing with the i2c core?
> Fixed, changed to I2C_SMBUS_READ/WRITE as Jean Delvare proposed.
> > 
> > > +static const struct stmp3xxx_dma_command cmd_i2c_select = {
> > > +	.cmd =	BF(1, APBX_CHn_CMD_XFER_COUNT)	|
> > > +		BF(1, APBX_CHn_CMD_CMDWORDS)	|
> > > +		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
> > > +		BM_APBX_CHn_CMD_CHAIN		|
> > > +		BF(BV_APBX_CHn_CMD_COMMAND__DMA_READ, APBX_CHn_CMD_COMMAND),
> > 
> > what is BF() ?
> it is the macro from arch/arm/plat-stmp3xxx/include/mach/platform.h,
> abbreviated "bitfield" :) For example, BF(1, APBX_CHn_CMD_CMDWORDS) is
> expanded like 
> ((1 << BP_APBX_CHn_CMD_CMDWORDS) & BM_APBX_CHn_CMD_CMDWORDS).
> BP_xxx stuff means bitfield position, BM_xxx - bitfield mask. 

yuck. I don't like people hiding thinks in macros for what is very
little gain, especially when an extant constant is being used!

-- 
Ben (ben-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org, http://www.fluff.org/)

  'a smiley only costs 4 bytes'

Re: [PATCH, RFC] Freescale STMP: i2c driver

[dmitry pervushin]

On Mon, 2009-06-22 at 11:51 +0100, Ben Dooks wrote:
> On Tue, Jun 16, 2009 at 08:25:39PM +0400, dmitry pervushin wrote:
> > Hello Ben,
> > 
> > I am sending the updated patch in next message, and this message is just
> > to answer your questions/concerns.\
> > 
> > [...]
> > > > +#include <mach/regs-apbx.h>
> > > > +
> > > > +static const u32 I2C_READ = 1,
> > > > +		 I2C_WRITE = 0;
> > > 
> > > do you really want to be defining things with a prefix of I2C, thatB
> > > might end up clashing with the i2c core?
> > Fixed, changed to I2C_SMBUS_READ/WRITE as Jean Delvare proposed.
> > > 
> > > > +static const struct stmp3xxx_dma_command cmd_i2c_select = {
> > > > +	.cmd =	BF(1, APBX_CHn_CMD_XFER_COUNT)	|
> > > > +		BF(1, APBX_CHn_CMD_CMDWORDS)	|
> > > > +		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
> > > > +		BM_APBX_CHn_CMD_CHAIN		|
> > > > +		BF(BV_APBX_CHn_CMD_COMMAND__DMA_READ, APBX_CHn_CMD_COMMAND),
> > > 
> > > what is BF() ?
> > it is the macro from arch/arm/plat-stmp3xxx/include/mach/platform.h,
> > abbreviated "bitfield" :) For example, BF(1, APBX_CHn_CMD_CMDWORDS) is
> > expanded like 
> > ((1 << BP_APBX_CHn_CMD_CMDWORDS) & BM_APBX_CHn_CMD_CMDWORDS).
> > BP_xxx stuff means bitfield position, BM_xxx - bitfield mask. 
> 
> yuck. I don't like people hiding thinks in macros for what is very
> little gain, especially when an extant constant is being used!
I hope that your personal preferences do not mix with patches merging process :)
However.. the updated patch is in the next message, again.

Re: [PATCH, RFC] Freescale STMP: i2c driver

[Ben Dooks]

any chance of an reply or update driver for inclusion?

-- 
Ben (ben-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org, http://www.fluff.org/)

  'a smiley only costs 4 bytes'

Re: [PATCH, RFC] Freescale STMP: i2c driver

[dmitry pervushin]

On Mon, 2009-06-15 at 09:19 +0100, Ben Dooks wrote:
> any chance of an reply or update driver for inclusion?
Here it is:

From: Dmitrij Frasenyak <d.frasenyak-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
Signed-off-by: dmitry pervushin <dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>

Add I2C driver for Freescale STMP boards

---
 drivers/i2c/busses/Kconfig        |    7 
 drivers/i2c/busses/Makefile       |    1 
 drivers/i2c/busses/i2c-stmp378x.c |  448 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 456 insertions(+)

Index: linux-2.6-arm/drivers/i2c/busses/Kconfig
===================================================================
--- linux-2.6-arm.orig/drivers/i2c/busses/Kconfig
+++ linux-2.6-arm/drivers/i2c/busses/Kconfig
@@ -513,6 +513,13 @@ config I2C_SIMTEC
 	  This driver can also be built as a module. If so, the module
 	  will be called i2c-simtec.
 
+config I2C_STMP378X
+	tristate "STMP378x I2C adapter"
+	depends on ARCH_STMP378X
+	help
+	  Include support of I2C adapter on Freescale STMP378x board; to build
+	  the driver as a module, say M here - module will be called i2c-stmp378x.
+
 config I2C_VERSATILE
 	tristate "ARM Versatile/Realview I2C bus support"
 	depends on ARCH_VERSATILE || ARCH_REALVIEW
Index: linux-2.6-arm/drivers/i2c/busses/Makefile
===================================================================
--- linux-2.6-arm.orig/drivers/i2c/busses/Makefile
+++ linux-2.6-arm/drivers/i2c/busses/Makefile
@@ -48,6 +48,7 @@ obj-$(CONFIG_I2C_S6000)		+= i2c-s6000.o
 obj-$(CONFIG_I2C_SH7760)	+= i2c-sh7760.o
 obj-$(CONFIG_I2C_SH_MOBILE)	+= i2c-sh_mobile.o
 obj-$(CONFIG_I2C_SIMTEC)	+= i2c-simtec.o
+obj-$(CONFIG_I2C_STMP378X)	+= i2c-stmp378x.o
 obj-$(CONFIG_I2C_VERSATILE)	+= i2c-versatile.o
 
 # External I2C/SMBus adapter drivers
Index: linux-2.6-arm/drivers/i2c/busses/i2c-stmp378x.c
===================================================================
--- /dev/null
+++ linux-2.6-arm/drivers/i2c/busses/i2c-stmp378x.c
@@ -0,0 +1,448 @@
+/*
+ * Freescale STMP378X I2C bus driver
+ *
+ * Author: Dmitrij Frasenyak <sed-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
+ *
+ * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/completion.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
+
+#include <mach/platform.h>
+#include <mach/stmp3xxx.h>
+#include <mach/dma.h>
+#include <mach/regs-i2c.h>
+#include <mach/regs-apbx.h>
+
+static const struct stmp3xxx_dma_command cmd_i2c_select = {
+	.cmd =	BF(1, APBX_CHn_CMD_XFER_COUNT)	|
+		BF(1, APBX_CHn_CMD_CMDWORDS)	|
+		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
+		BM_APBX_CHn_CMD_CHAIN		|
+		BF(BV_APBX_CHn_CMD_COMMAND__DMA_READ, APBX_CHn_CMD_COMMAND),
+	.pio_words = {
+		[0] = 	BM_I2C_CTRL0_RETAIN_CLOCK   |
+			BM_I2C_CTRL0_PRE_SEND_START |
+			BM_I2C_CTRL0_MASTER_MODE    |
+			BM_I2C_CTRL0_DIRECTION      |
+			BF(1, I2C_CTRL0_XFER_COUNT),
+	},
+};
+
+static const struct stmp3xxx_dma_command cmd_i2c_write = {
+	.cmd =	BM_APBX_CHn_CMD_SEMAPHORE	|
+		BF(1, APBX_CHn_CMD_CMDWORDS)	|
+		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
+		BM_APBX_CHn_CMD_IRQONCMPLT	|
+		BF(BV_APBX_CHn_CMD_COMMAND__DMA_READ, APBX_CHn_CMD_COMMAND),
+	.pio_words = {
+		[0] =	BM_I2C_CTRL0_PRE_SEND_START |
+			BM_I2C_CTRL0_MASTER_MODE    |
+			BM_I2C_CTRL0_DIRECTION,
+	},
+};
+
+static const struct stmp3xxx_dma_command cmd_i2c_read = {
+	.cmd =	BM_APBX_CHn_CMD_SEMAPHORE	|
+		BF(1, APBX_CHn_CMD_CMDWORDS)	|
+		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
+		BM_APBX_CHn_CMD_IRQONCMPLT	|
+		BF(BV_APBX_CHn_CMD_COMMAND__DMA_WRITE, APBX_CHn_CMD_COMMAND),
+	.pio_words = {
+		[0] =	BM_I2C_CTRL0_SEND_NAK_ON_LAST	|
+			BM_I2C_CTRL0_MASTER_MODE,
+	},
+};
+
+/**
+ * struct stmp378x_i2c_dev - STMP3xxx I2C adapter data
+ * @dev: the associated platform_device
+ * @cmd_complete: the completion structure indicating that message has been
+ * 	transferred
+ * @cmd_err: current error code
+ * @adapter: the adapter we implement
+ * @io: io address
+ * @irq: irq number
+ * @dma: dma channel
+ * @bufv: pointer to the dma buffer
+ * @bufp: physical address of the dma buffer
+ * @i2c_dma_read: "read" dma chain (read request and then write)
+ * @i2c_dma_write: "write" dma chain (the single combined write request)
+ */
+struct stmp378x_i2c_dev {
+	struct device		*dev;
+	int			irq;
+	struct completion	cmd_complete;
+	u32			cmd_err;
+	struct i2c_adapter	adapter;
+	void __iomem 		*io;
+	unsigned		dma;
+
+	dma_addr_t		bufp;
+	unsigned char		*bufv;
+
+	struct stmp3xxx_dma_descriptor i2c_dma_read[2],
+				       i2c_dma_write;
+};
+
+static int stmp378x_i2c_init(struct stmp378x_i2c_dev *dev)
+{
+	int err;
+
+	err = stmp3xxx_dma_request(dev->dma, dev->dev, dev_name(dev->dev));
+	if (err)
+		goto out;
+	stmp3xxx_reset_block(dev->io, true);
+
+	dev->bufv = dma_alloc_coherent(dev->dev, PAGE_SIZE,
+				       &dev->bufp, GFP_KERNEL);
+	if (!dev->bufv)
+		goto out_dma;
+
+	err = stmp3xxx_request_pin_group(dev->dev->platform_data,
+			dev_name(dev->dev));
+	if (err)
+		goto out_free;
+
+	err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_read[0]);
+	if (err)
+		goto out_rd0;
+	err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_read[1]);
+	if (err)
+		goto out_rd1;
+	err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_write);
+	if (err)
+		goto out_wr;
+
+	stmp3xxx_dma_reset_channel(dev->dma);
+	stmp3xxx_dma_clear_interrupt(dev->dma);
+	stmp3xxx_dma_enable_interrupt(dev->dma);
+
+	return 0;
+/*
+	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_write);
+*/
+out_wr:
+	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[1]);
+out_rd1:
+	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[0]);
+out_rd0:
+	stmp3xxx_release_pin_group(dev->dev->platform_data, dev_name(dev->dev));
+out_free:
+	dma_free_coherent(dev->dev, PAGE_SIZE, dev->bufv, dev->bufp);
+out_dma:
+	stmp3xxx_dma_release(dev->dma);
+out:
+	return err;
+}
+
+static void stmp378x_i2c_release(struct stmp378x_i2c_dev *dev)
+{
+	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_write);
+	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[1]);
+	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[0]);
+	dma_free_coherent(dev->dev, PAGE_SIZE, dev->bufv, dev->bufp);
+	stmp3xxx_release_pin_group(dev->dev->platform_data, dev_name(dev->dev));
+	stmp3xxx_dma_release(dev->dma);
+}
+/*
+ * Low level master read/write transaction.
+ */
+static int stmp378x_i2c_xfer_msg(struct i2c_adapter *adap,
+				 struct i2c_msg *msg, int stop)
+{
+	struct stmp378x_i2c_dev *dev = i2c_get_adapdata(adap);
+	int err;
+	struct stmp3xxx_dma_descriptor *c, *r;
+
+	init_completion(&dev->cmd_complete);
+	dev->cmd_err = 0;
+
+	if ((msg->len == 0) || (msg->len > (PAGE_SIZE - 1)))
+		return -EINVAL;
+
+	if (msg->flags & I2C_M_RD) {
+
+		c = &dev->i2c_dma_read[0];
+		r = &dev->i2c_dma_read[1];
+
+		/* first, setup the SELECT command */
+		memcpy(c->command, &cmd_i2c_select, sizeof(cmd_i2c_select));
+		c->command->buf_ptr = dev->bufp;
+		dev->bufv[0] = msg->addr | I2C_SMBUS_READ;
+
+		/* then, setup the READ command */
+		memcpy(r->command, &cmd_i2c_read, sizeof(cmd_i2c_read));
+		r->command->cmd |= BF(msg->len, APBX_CHn_CMD_XFER_COUNT);
+		r->command->pio_words[0] |= BF(msg->len, I2C_CTRL0_XFER_COUNT);
+		if (stop)
+			r->command->pio_words[0] |= BM_I2C_CTRL0_POST_SEND_STOP;
+		/*
+		 * yes, STMP controller can DMA transfer the data from any
+		 * byte boundary
+		 */
+		r->command->buf_ptr = dev->bufp + 1;
+
+		/* and chain them together */
+		c->command->next = r->handle;
+
+	} else {
+
+		c = &dev->i2c_dma_write;
+		memcpy(c->command, &cmd_i2c_write, sizeof(cmd_i2c_write));
+		c->command->cmd |= BF(msg->len + 1, APBX_CHn_CMD_XFER_COUNT);
+		c->command->pio_words[0] |=
+				   BF(msg->len + 1, I2C_CTRL0_XFER_COUNT);
+		if (stop)
+			c->command->pio_words[0] |=
+				   BM_I2C_CTRL0_POST_SEND_STOP;
+		dev->bufv[0] = msg->addr | I2C_SMBUS_WRITE;
+		memcpy(dev->bufv + 1, msg->buf, msg->len);
+	}
+
+	stmp3xxx_dma_go(dev->dma, c, 1);
+
+	err = wait_for_completion_interruptible_timeout(&dev->cmd_complete,
+							msecs_to_jiffies(1000));
+
+	if (err < 0) {
+		dev_dbg(dev->dev, "controler is timed out\n");
+		return -ETIMEDOUT;
+	}
+	if (!dev->cmd_err && (msg->flags & I2C_M_RD))
+		memcpy(msg->buf, dev->bufv + 1, msg->len);
+
+	dev_dbg(dev->dev, "done with err=%d\n", dev->cmd_err);
+
+	return dev->cmd_err;
+}
+
+
+static int
+stmp378x_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
+{
+	int i;
+	int err;
+
+	if (!msgs->len)
+		return -EINVAL;
+
+	for (i = 0; i < num; i++) {
+		err = stmp378x_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
+		if (err)
+			return err;
+	}
+	return num;
+}
+
+static u32
+stmp378x_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+}
+
+#define I2C_IRQ_MASK 0x000000FF
+static irqreturn_t
+stmp378x_i2c_isr(int this_irq, void *dev_id)
+{
+	struct stmp378x_i2c_dev *dev = dev_id;
+	u32 stat;
+	u32 done_mask = BM_I2C_CTRL1_DATA_ENGINE_CMPLT_IRQ |
+			BM_I2C_CTRL1_BUS_FREE_IRQ ;
+
+	stat = readl(HW_I2C_CTRL1 + dev->io) & I2C_IRQ_MASK;
+	if (!stat)
+		return IRQ_NONE;
+
+	if (stat & BM_I2C_CTRL1_NO_SLAVE_ACK_IRQ) {
+		dev->cmd_err = -EREMOTEIO;
+
+		/*
+		 * Stop DMA
+		 * Clear NAK
+		 */
+		stmp3xxx_setl(BM_I2C_CTRL1_CLR_GOT_A_NAK,
+			      HW_I2C_CTRL1 + dev->io);
+		stmp3xxx_dma_reset_channel(dev->dma);
+		stmp3xxx_dma_clear_interrupt(dev->dma);
+
+		complete(&dev->cmd_complete);
+
+		goto done;
+	}
+
+	/* Don't care about  BM_I2C_CTRL1_OVERSIZE_XFER_TERM_IRQ */
+	if (stat & (BM_I2C_CTRL1_EARLY_TERM_IRQ |
+		    BM_I2C_CTRL1_MASTER_LOSS_IRQ |
+		    BM_I2C_CTRL1_SLAVE_STOP_IRQ |
+		    BM_I2C_CTRL1_SLAVE_IRQ)) {
+		dev->cmd_err = -EIO;
+		complete(&dev->cmd_complete);
+		goto done;
+	}
+
+	if ((stat & done_mask) == done_mask)
+		complete(&dev->cmd_complete);
+
+done:
+	stmp3xxx_clearl(stat, dev->io + HW_I2C_CTRL1);
+	return IRQ_HANDLED;
+}
+
+static const struct i2c_algorithm stmp378x_i2c_algo = {
+	.master_xfer	= stmp378x_i2c_xfer,
+	.functionality	= stmp378x_i2c_func,
+};
+
+
+static int __devinit
+stmp378x_i2c_probe(struct platform_device *pdev)
+{
+	struct stmp378x_i2c_dev	*dev;
+	struct i2c_adapter	*adap;
+	struct resource		*mem, *dma;
+	int err = 0;
+
+	dev = kzalloc(sizeof(struct stmp378x_i2c_dev), GFP_KERNEL);
+	if (!dev) {
+		dev_err(&pdev->dev, "no mem \n");
+		return -ENOMEM;
+	}
+
+	dev->irq = platform_get_irq(pdev, 0); /* Error */
+	if (dev->irq < 0) {
+		dev_err(&pdev->dev, "no err_irq resource\n");
+		err = dev->irq;
+		goto nores;
+	}
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mem) {
+		dev_err(&pdev->dev, "no memory window\n");
+		err = -ENODEV;
+		goto nores;
+	}
+
+	dma = platform_get_resource(pdev, IORESOURCE_DMA, 0);
+	if (!dma) {
+		dev_err(&pdev->dev, "no dma channel\n");
+		err = -ENODEV;
+		goto nores;
+	}
+	dev->dma = dma->start;
+
+	dev->dev = &pdev->dev;
+	dev->io = ioremap(mem->start, resource_size(mem));
+	if (!dev->io) {
+		dev_err(&pdev->dev, "cannot ioremap\n");
+		err = -ENXIO;
+		goto nores;
+	}
+
+	err = request_irq(dev->irq, stmp378x_i2c_isr, 0, pdev->name, dev);
+	if (err) {
+		dev_err(&pdev->dev, "Can't get IRQ\n");
+		goto no_err_irq;
+	}
+
+	err = stmp378x_i2c_init(dev);
+	if (err) {
+		dev_err(&pdev->dev, "HW Init failed\n");
+		goto init_failed;
+	}
+
+	stmp3xxx_setl(0xFF00, dev->io + HW_I2C_CTRL1);
+
+	adap = &dev->adapter;
+	i2c_set_adapdata(adap, dev);
+	adap->owner = THIS_MODULE;
+	adap->class = I2C_CLASS_TV_DIGITAL;
+	strncpy(adap->name, "378x I2C adapter", sizeof(adap->name));
+	adap->algo = &stmp378x_i2c_algo;
+	adap->dev.parent = &pdev->dev;
+
+	adap->nr = pdev->id;
+	err = i2c_add_numbered_adapter(adap);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to add adapter\n");
+		goto no_i2c_adapter;
+
+	}
+
+	return 0;
+
+no_i2c_adapter:
+	stmp378x_i2c_release(dev);
+init_failed:
+	free_irq(dev->irq, dev);
+no_err_irq:
+	iounmap(dev->io);
+nores:
+	kfree(dev);
+	return err;
+}
+
+static int __devexit
+stmp378x_i2c_remove(struct platform_device *pdev)
+{
+	struct stmp378x_i2c_dev	*dev = platform_get_drvdata(pdev);
+	int res;
+
+	res = i2c_del_adapter(&dev->adapter);
+	if (res)
+		return -EBUSY;
+
+	stmp378x_i2c_release(dev);
+
+	platform_set_drvdata(pdev, NULL);
+
+	free_irq(dev->irq, dev);
+	iounmap(dev->io);
+
+	kfree(dev);
+	return 0;
+}
+
+static struct platform_driver stmp378x_i2c_driver = {
+	.probe		= stmp378x_i2c_probe,
+	.remove		= __devexit_p(stmp378x_i2c_remove),
+	.driver		= {
+		.name	= "i2c_stmp3xxx",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init stmp378x_i2c_init_driver(void)
+{
+	return platform_driver_register(&stmp378x_i2c_driver);
+}
+module_init(stmp378x_i2c_init_driver);
+
+static void __exit stmp378x_i2c_exit_driver(void)
+{
+	platform_driver_unregister(&stmp378x_i2c_driver);
+}
+module_exit(stmp378x_i2c_exit_driver);
+
+MODULE_AUTHOR("d.frasenyak-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org");
+MODULE_DESCRIPTION("I2C for Freescale STMP378x");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:i2c_stmp3xxx");

Re: [PATCH, RFC] Freescale STMP: i2c driver

[Ben Dooks]

On Tue, Jun 16, 2009 at 08:31:53PM +0400, dmitry pervushin wrote:
> On Mon, 2009-06-15 at 09:19 +0100, Ben Dooks wrote:
> > any chance of an reply or update driver for inclusion?
> Here it is:
>
> From: Dmitrij Frasenyak <d.frasenyak-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
> Signed-off-by: dmitry pervushin <dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
> 
> Add I2C driver for Freescale STMP boards

Sorry, forgot to come back and sort this one out.

The From: field is fine, but the first signed-off-by should also be
from Dimirij as well (to say that as the creator he is accepting that
this is suitable for inclusion - I do hope you've both read at-least
section 12 of Documentation/SubmittingPatches).

The signed-off-by should go after the description text, and must have
Dimirij's Signed-off-By, and it would be nice to have yours in there
too.
 
> ---
>  drivers/i2c/busses/Kconfig        |    7 
>  drivers/i2c/busses/Makefile       |    1 
>  drivers/i2c/busses/i2c-stmp378x.c |  448 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 456 insertions(+)
> 
> Index: linux-2.6-arm/drivers/i2c/busses/Kconfig
> ===================================================================
> --- linux-2.6-arm.orig/drivers/i2c/busses/Kconfig
> +++ linux-2.6-arm/drivers/i2c/busses/Kconfig
> @@ -513,6 +513,13 @@ config I2C_SIMTEC
>  	  This driver can also be built as a module. If so, the module
>  	  will be called i2c-simtec.
>  
> +config I2C_STMP378X
> +	tristate "STMP378x I2C adapter"
> +	depends on ARCH_STMP378X
> +	help
> +	  Include support of I2C adapter on Freescale STMP378x board; to build
> +	  the driver as a module, say M here - module will be called i2c-stmp378x.
> +
>  config I2C_VERSATILE
>  	tristate "ARM Versatile/Realview I2C bus support"
>  	depends on ARCH_VERSATILE || ARCH_REALVIEW
> Index: linux-2.6-arm/drivers/i2c/busses/Makefile
> ===================================================================
> --- linux-2.6-arm.orig/drivers/i2c/busses/Makefile
> +++ linux-2.6-arm/drivers/i2c/busses/Makefile
> @@ -48,6 +48,7 @@ obj-$(CONFIG_I2C_S6000)		+= i2c-s6000.o
>  obj-$(CONFIG_I2C_SH7760)	+= i2c-sh7760.o
>  obj-$(CONFIG_I2C_SH_MOBILE)	+= i2c-sh_mobile.o
>  obj-$(CONFIG_I2C_SIMTEC)	+= i2c-simtec.o
> +obj-$(CONFIG_I2C_STMP378X)	+= i2c-stmp378x.o
>  obj-$(CONFIG_I2C_VERSATILE)	+= i2c-versatile.o
>  
>  # External I2C/SMBus adapter drivers
> Index: linux-2.6-arm/drivers/i2c/busses/i2c-stmp378x.c
> ===================================================================
> --- /dev/null
> +++ linux-2.6-arm/drivers/i2c/busses/i2c-stmp378x.c
> @@ -0,0 +1,448 @@
> +/*
> + * Freescale STMP378X I2C bus driver
> + *
> + * Author: Dmitrij Frasenyak <sed-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
> + *
> + * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
> + * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
> + */
> +
> +/*
> + * The code contained herein is licensed under the GNU General Public
> + * License. You may obtain a copy of the GNU General Public License
> + * Version 2 or later at the following locations:
> + *
> + * http://www.opensource.org/licenses/gpl-license.html
> + * http://www.gnu.org/copyleft/gpl.html
> + */
> +#include <linux/module.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/err.h>
> +#include <linux/interrupt.h>
> +#include <linux/completion.h>
> +#include <linux/platform_device.h>
> +#include <linux/clk.h>
> +#include <linux/io.h>
> +#include <linux/dma-mapping.h>
> +
> +#include <mach/platform.h>
> +#include <mach/stmp3xxx.h>
> +#include <mach/dma.h>
> +#include <mach/regs-i2c.h>
> +#include <mach/regs-apbx.h>
> +
> +static const struct stmp3xxx_dma_command cmd_i2c_select = {
> +	.cmd =	BF(1, APBX_CHn_CMD_XFER_COUNT)	|
> +		BF(1, APBX_CHn_CMD_CMDWORDS)	|
> +		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
> +		BM_APBX_CHn_CMD_CHAIN		|
> +		BF(BV_APBX_CHn_CMD_COMMAND__DMA_READ, APBX_CHn_CMD_COMMAND),
> +	.pio_words = {
> +		[0] = 	BM_I2C_CTRL0_RETAIN_CLOCK   |
> +			BM_I2C_CTRL0_PRE_SEND_START |
> +			BM_I2C_CTRL0_MASTER_MODE    |
> +			BM_I2C_CTRL0_DIRECTION      |
> +			BF(1, I2C_CTRL0_XFER_COUNT),
> +	},
> +};
> +
> +static const struct stmp3xxx_dma_command cmd_i2c_write = {
> +	.cmd =	BM_APBX_CHn_CMD_SEMAPHORE	|
> +		BF(1, APBX_CHn_CMD_CMDWORDS)	|
> +		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
> +		BM_APBX_CHn_CMD_IRQONCMPLT	|
> +		BF(BV_APBX_CHn_CMD_COMMAND__DMA_READ, APBX_CHn_CMD_COMMAND),
> +	.pio_words = {
> +		[0] =	BM_I2C_CTRL0_PRE_SEND_START |
> +			BM_I2C_CTRL0_MASTER_MODE    |
> +			BM_I2C_CTRL0_DIRECTION,
> +	},
> +};
> +
> +static const struct stmp3xxx_dma_command cmd_i2c_read = {
> +	.cmd =	BM_APBX_CHn_CMD_SEMAPHORE	|
> +		BF(1, APBX_CHn_CMD_CMDWORDS)	|
> +		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
> +		BM_APBX_CHn_CMD_IRQONCMPLT	|
> +		BF(BV_APBX_CHn_CMD_COMMAND__DMA_WRITE, APBX_CHn_CMD_COMMAND),
> +	.pio_words = {
> +		[0] =	BM_I2C_CTRL0_SEND_NAK_ON_LAST	|
> +			BM_I2C_CTRL0_MASTER_MODE,
> +	},
> +};
> +
> +/**
> + * struct stmp378x_i2c_dev - STMP3xxx I2C adapter data
> + * @dev: the associated platform_device
> + * @cmd_complete: the completion structure indicating that message has been
> + * 	transferred
> + * @cmd_err: current error code
> + * @adapter: the adapter we implement
> + * @io: io address
> + * @irq: irq number
> + * @dma: dma channel
> + * @bufv: pointer to the dma buffer
> + * @bufp: physical address of the dma buffer
> + * @i2c_dma_read: "read" dma chain (read request and then write)
> + * @i2c_dma_write: "write" dma chain (the single combined write request)
> + */
> +struct stmp378x_i2c_dev {
> +	struct device		*dev;
> +	int			irq;
> +	struct completion	cmd_complete;
> +	u32			cmd_err;
> +	struct i2c_adapter	adapter;
> +	void __iomem 		*io;
> +	unsigned		dma;
> +
> +	dma_addr_t		bufp;
> +	unsigned char		*bufv;
> +
> +	struct stmp3xxx_dma_descriptor i2c_dma_read[2],
> +				       i2c_dma_write;
> +};
> +
> +static int stmp378x_i2c_init(struct stmp378x_i2c_dev *dev)
> +{
> +	int err;
> +
> +	err = stmp3xxx_dma_request(dev->dma, dev->dev, dev_name(dev->dev));
> +	if (err)
> +		goto out;
> +	stmp3xxx_reset_block(dev->io, true);
> +
> +	dev->bufv = dma_alloc_coherent(dev->dev, PAGE_SIZE,
> +				       &dev->bufp, GFP_KERNEL);
> +	if (!dev->bufv)
> +		goto out_dma;
> +
> +	err = stmp3xxx_request_pin_group(dev->dev->platform_data,
> +			dev_name(dev->dev));
> +	if (err)
> +		goto out_free;
> +
> +	err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_read[0]);
> +	if (err)
> +		goto out_rd0;
> +	err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_read[1]);
> +	if (err)
> +		goto out_rd1;
> +	err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_write);
> +	if (err)
> +		goto out_wr;
> +
> +	stmp3xxx_dma_reset_channel(dev->dma);
> +	stmp3xxx_dma_clear_interrupt(dev->dma);
> +	stmp3xxx_dma_enable_interrupt(dev->dma);
> +
> +	return 0;
> +/*
> +	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_write);
> +*/
> +out_wr:
> +	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[1]);
> +out_rd1:
> +	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[0]);
> +out_rd0:
> +	stmp3xxx_release_pin_group(dev->dev->platform_data, dev_name(dev->dev));
> +out_free:
> +	dma_free_coherent(dev->dev, PAGE_SIZE, dev->bufv, dev->bufp);
> +out_dma:
> +	stmp3xxx_dma_release(dev->dma);
> +out:
> +	return err;
> +}
> +
> +static void stmp378x_i2c_release(struct stmp378x_i2c_dev *dev)
> +{
> +	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_write);
> +	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[1]);
> +	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[0]);
> +	dma_free_coherent(dev->dev, PAGE_SIZE, dev->bufv, dev->bufp);
> +	stmp3xxx_release_pin_group(dev->dev->platform_data, dev_name(dev->dev));
> +	stmp3xxx_dma_release(dev->dma);
> +}
> +/*
> + * Low level master read/write transaction.
> + */
> +static int stmp378x_i2c_xfer_msg(struct i2c_adapter *adap,
> +				 struct i2c_msg *msg, int stop)
> +{
> +	struct stmp378x_i2c_dev *dev = i2c_get_adapdata(adap);
> +	int err;
> +	struct stmp3xxx_dma_descriptor *c, *r;
> +
> +	init_completion(&dev->cmd_complete);
> +	dev->cmd_err = 0;
> +
> +	if ((msg->len == 0) || (msg->len > (PAGE_SIZE - 1)))
> +		return -EINVAL;
> +
> +	if (msg->flags & I2C_M_RD) {
> +
> +		c = &dev->i2c_dma_read[0];
> +		r = &dev->i2c_dma_read[1];
> +
> +		/* first, setup the SELECT command */
> +		memcpy(c->command, &cmd_i2c_select, sizeof(cmd_i2c_select));
> +		c->command->buf_ptr = dev->bufp;
> +		dev->bufv[0] = msg->addr | I2C_SMBUS_READ;
> +
> +		/* then, setup the READ command */
> +		memcpy(r->command, &cmd_i2c_read, sizeof(cmd_i2c_read));
> +		r->command->cmd |= BF(msg->len, APBX_CHn_CMD_XFER_COUNT);
> +		r->command->pio_words[0] |= BF(msg->len, I2C_CTRL0_XFER_COUNT);
> +		if (stop)
> +			r->command->pio_words[0] |= BM_I2C_CTRL0_POST_SEND_STOP;
> +		/*
> +		 * yes, STMP controller can DMA transfer the data from any
> +		 * byte boundary
> +		 */
> +		r->command->buf_ptr = dev->bufp + 1;
> +
> +		/* and chain them together */
> +		c->command->next = r->handle;
> +
> +	} else {
> +
> +		c = &dev->i2c_dma_write;
> +		memcpy(c->command, &cmd_i2c_write, sizeof(cmd_i2c_write));
> +		c->command->cmd |= BF(msg->len + 1, APBX_CHn_CMD_XFER_COUNT);
> +		c->command->pio_words[0] |=
> +				   BF(msg->len + 1, I2C_CTRL0_XFER_COUNT);
> +		if (stop)
> +			c->command->pio_words[0] |=
> +				   BM_I2C_CTRL0_POST_SEND_STOP;
> +		dev->bufv[0] = msg->addr | I2C_SMBUS_WRITE;
> +		memcpy(dev->bufv + 1, msg->buf, msg->len);
> +	}
> +
> +	stmp3xxx_dma_go(dev->dma, c, 1);
> +
> +	err = wait_for_completion_interruptible_timeout(&dev->cmd_complete,
> +							msecs_to_jiffies(1000));
> +
> +	if (err < 0) {
> +		dev_dbg(dev->dev, "controler is timed out\n");
> +		return -ETIMEDOUT;
> +	}
> +	if (!dev->cmd_err && (msg->flags & I2C_M_RD))
> +		memcpy(msg->buf, dev->bufv + 1, msg->len);
> +
> +	dev_dbg(dev->dev, "done with err=%d\n", dev->cmd_err);
> +
> +	return dev->cmd_err;
> +}
> +
> +
> +static int
> +stmp378x_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
> +{
> +	int i;
> +	int err;
> +
> +	if (!msgs->len)
> +		return -EINVAL;
> +
> +	for (i = 0; i < num; i++) {
> +		err = stmp378x_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
> +		if (err)
> +			return err;
> +	}
> +	return num;
> +}
> +
> +static u32
> +stmp378x_i2c_func(struct i2c_adapter *adap)
> +{
> +	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
> +}
> +
> +#define I2C_IRQ_MASK 0x000000FF
> +static irqreturn_t
> +stmp378x_i2c_isr(int this_irq, void *dev_id)
> +{
> +	struct stmp378x_i2c_dev *dev = dev_id;
> +	u32 stat;
> +	u32 done_mask = BM_I2C_CTRL1_DATA_ENGINE_CMPLT_IRQ |
> +			BM_I2C_CTRL1_BUS_FREE_IRQ ;
> +
> +	stat = readl(HW_I2C_CTRL1 + dev->io) & I2C_IRQ_MASK;
> +	if (!stat)
> +		return IRQ_NONE;
> +
> +	if (stat & BM_I2C_CTRL1_NO_SLAVE_ACK_IRQ) {
> +		dev->cmd_err = -EREMOTEIO;
> +
> +		/*
> +		 * Stop DMA
> +		 * Clear NAK
> +		 */
> +		stmp3xxx_setl(BM_I2C_CTRL1_CLR_GOT_A_NAK,
> +			      HW_I2C_CTRL1 + dev->io);
> +		stmp3xxx_dma_reset_channel(dev->dma);
> +		stmp3xxx_dma_clear_interrupt(dev->dma);
> +
> +		complete(&dev->cmd_complete);
> +
> +		goto done;
> +	}
> +
> +	/* Don't care about  BM_I2C_CTRL1_OVERSIZE_XFER_TERM_IRQ */
> +	if (stat & (BM_I2C_CTRL1_EARLY_TERM_IRQ |
> +		    BM_I2C_CTRL1_MASTER_LOSS_IRQ |
> +		    BM_I2C_CTRL1_SLAVE_STOP_IRQ |
> +		    BM_I2C_CTRL1_SLAVE_IRQ)) {
> +		dev->cmd_err = -EIO;
> +		complete(&dev->cmd_complete);
> +		goto done;
> +	}
> +
> +	if ((stat & done_mask) == done_mask)
> +		complete(&dev->cmd_complete);
> +
> +done:
> +	stmp3xxx_clearl(stat, dev->io + HW_I2C_CTRL1);
> +	return IRQ_HANDLED;
> +}
> +
> +static const struct i2c_algorithm stmp378x_i2c_algo = {
> +	.master_xfer	= stmp378x_i2c_xfer,
> +	.functionality	= stmp378x_i2c_func,
> +};
> +
> +
> +static int __devinit
> +stmp378x_i2c_probe(struct platform_device *pdev)
> +{
> +	struct stmp378x_i2c_dev	*dev;
> +	struct i2c_adapter	*adap;
> +	struct resource		*mem, *dma;
> +	int err = 0;
> +
> +	dev = kzalloc(sizeof(struct stmp378x_i2c_dev), GFP_KERNEL);
> +	if (!dev) {
> +		dev_err(&pdev->dev, "no mem \n");
> +		return -ENOMEM;
> +	}
> +
> +	dev->irq = platform_get_irq(pdev, 0); /* Error */
> +	if (dev->irq < 0) {
> +		dev_err(&pdev->dev, "no err_irq resource\n");
> +		err = dev->irq;
> +		goto nores;
> +	}
> +
> +	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!mem) {
> +		dev_err(&pdev->dev, "no memory window\n");
> +		err = -ENODEV;
> +		goto nores;
> +	}
> +
> +	dma = platform_get_resource(pdev, IORESOURCE_DMA, 0);
> +	if (!dma) {
> +		dev_err(&pdev->dev, "no dma channel\n");
> +		err = -ENODEV;
> +		goto nores;
> +	}
> +	dev->dma = dma->start;
> +
> +	dev->dev = &pdev->dev;
> +	dev->io = ioremap(mem->start, resource_size(mem));
> +	if (!dev->io) {
> +		dev_err(&pdev->dev, "cannot ioremap\n");
> +		err = -ENXIO;
> +		goto nores;
> +	}
> +
> +	err = request_irq(dev->irq, stmp378x_i2c_isr, 0, pdev->name, dev);
> +	if (err) {
> +		dev_err(&pdev->dev, "Can't get IRQ\n");
> +		goto no_err_irq;
> +	}
> +
> +	err = stmp378x_i2c_init(dev);
> +	if (err) {
> +		dev_err(&pdev->dev, "HW Init failed\n");
> +		goto init_failed;
> +	}
> +
> +	stmp3xxx_setl(0xFF00, dev->io + HW_I2C_CTRL1);
> +
> +	adap = &dev->adapter;
> +	i2c_set_adapdata(adap, dev);
> +	adap->owner = THIS_MODULE;
> +	adap->class = I2C_CLASS_TV_DIGITAL;
> +	strncpy(adap->name, "378x I2C adapter", sizeof(adap->name));
> +	adap->algo = &stmp378x_i2c_algo;
> +	adap->dev.parent = &pdev->dev;
> +
> +	adap->nr = pdev->id;
> +	err = i2c_add_numbered_adapter(adap);
> +	if (err) {
> +		dev_err(&pdev->dev, "Failed to add adapter\n");
> +		goto no_i2c_adapter;
> +
> +	}
> +
> +	return 0;
> +
> +no_i2c_adapter:
> +	stmp378x_i2c_release(dev);
> +init_failed:
> +	free_irq(dev->irq, dev);
> +no_err_irq:
> +	iounmap(dev->io);
> +nores:
> +	kfree(dev);
> +	return err;
> +}
> +
> +static int __devexit
> +stmp378x_i2c_remove(struct platform_device *pdev)
> +{
> +	struct stmp378x_i2c_dev	*dev = platform_get_drvdata(pdev);
> +	int res;
> +
> +	res = i2c_del_adapter(&dev->adapter);
> +	if (res)
> +		return -EBUSY;
> +
> +	stmp378x_i2c_release(dev);
> +
> +	platform_set_drvdata(pdev, NULL);
> +
> +	free_irq(dev->irq, dev);
> +	iounmap(dev->io);
> +
> +	kfree(dev);
> +	return 0;
> +}
> +
> +static struct platform_driver stmp378x_i2c_driver = {
> +	.probe		= stmp378x_i2c_probe,
> +	.remove		= __devexit_p(stmp378x_i2c_remove),
> +	.driver		= {
> +		.name	= "i2c_stmp3xxx",
> +		.owner	= THIS_MODULE,
> +	},
> +};
> +
> +static int __init stmp378x_i2c_init_driver(void)
> +{
> +	return platform_driver_register(&stmp378x_i2c_driver);
> +}
> +module_init(stmp378x_i2c_init_driver);
> +
> +static void __exit stmp378x_i2c_exit_driver(void)
> +{
> +	platform_driver_unregister(&stmp378x_i2c_driver);
> +}
> +module_exit(stmp378x_i2c_exit_driver);
> +
> +MODULE_AUTHOR("d.frasenyak-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org");
> +MODULE_DESCRIPTION("I2C for Freescale STMP378x");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:i2c_stmp3xxx");
> 
> 
> --
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> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
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-- 
Ben (ben-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org, http://www.fluff.org/)

  'a smiley only costs 4 bytes'

Re: [PATCH, RFC] Freescale STMP: i2c driver

[dmitry pervushin]

On Mon, 2009-06-22 at 01:47 +0100, Ben Dooks wrote:
> On Tue, Jun 16, 2009 at 08:31:53PM +0400, dmitry pervushin wrote:
> > On Mon, 2009-06-15 at 09:19 +0100, Ben Dooks wrote:
> > > any chance of an reply or update driver for inclusion?
> > Here it is:
> >
> > From: Dmitrij Frasenyak <d.frasenyak-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
> > Signed-off-by: dmitry pervushin <dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
> > 
> > Add I2C driver for Freescale STMP boards

From: Dmitrij Frasenyak <d.frasenyak-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
Signed-off-by: Dmitrij Frasenyak <d.frasenyak-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
Signed-off-by: dmitry pervushin <dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>


>  
> > ---
> >  drivers/i2c/busses/Kconfig        |    7 
> >  drivers/i2c/busses/Makefile       |    1 
> >  drivers/i2c/busses/i2c-stmp378x.c |  448 ++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 456 insertions(+)
> > 
> > Index: linux-2.6-arm/drivers/i2c/busses/Kconfig
> > ===================================================================
> > --- linux-2.6-arm.orig/drivers/i2c/busses/Kconfig
> > +++ linux-2.6-arm/drivers/i2c/busses/Kconfig
> > @@ -513,6 +513,13 @@ config I2C_SIMTEC
> >  	  This driver can also be built as a module. If so, the module
> >  	  will be called i2c-simtec.
> >  
> > +config I2C_STMP378X
> > +	tristate "STMP378x I2C adapter"
> > +	depends on ARCH_STMP378X
> > +	help
> > +	  Include support of I2C adapter on Freescale STMP378x board; to build
> > +	  the driver as a module, say M here - module will be called i2c-stmp378x.
> > +
> >  config I2C_VERSATILE
> >  	tristate "ARM Versatile/Realview I2C bus support"
> >  	depends on ARCH_VERSATILE || ARCH_REALVIEW
> > Index: linux-2.6-arm/drivers/i2c/busses/Makefile
> > ===================================================================
> > --- linux-2.6-arm.orig/drivers/i2c/busses/Makefile
> > +++ linux-2.6-arm/drivers/i2c/busses/Makefile
> > @@ -48,6 +48,7 @@ obj-$(CONFIG_I2C_S6000)		+= i2c-s6000.o
> >  obj-$(CONFIG_I2C_SH7760)	+= i2c-sh7760.o
> >  obj-$(CONFIG_I2C_SH_MOBILE)	+= i2c-sh_mobile.o
> >  obj-$(CONFIG_I2C_SIMTEC)	+= i2c-simtec.o
> > +obj-$(CONFIG_I2C_STMP378X)	+= i2c-stmp378x.o
> >  obj-$(CONFIG_I2C_VERSATILE)	+= i2c-versatile.o
> >  
> >  # External I2C/SMBus adapter drivers
> > Index: linux-2.6-arm/drivers/i2c/busses/i2c-stmp378x.c
> > ===================================================================
> > --- /dev/null
> > +++ linux-2.6-arm/drivers/i2c/busses/i2c-stmp378x.c
> > @@ -0,0 +1,448 @@
> > +/*
> > + * Freescale STMP378X I2C bus driver
> > + *
> > + * Author: Dmitrij Frasenyak <sed-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
> > + *
> > + * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
> > + * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
> > + */
> > +
> > +/*
> > + * The code contained herein is licensed under the GNU General Public
> > + * License. You may obtain a copy of the GNU General Public License
> > + * Version 2 or later at the following locations:
> > + *
> > + * http://www.opensource.org/licenses/gpl-license.html
> > + * http://www.gnu.org/copyleft/gpl.html
> > + */
> > +#include <linux/module.h>
> > +#include <linux/delay.h>
> > +#include <linux/i2c.h>
> > +#include <linux/err.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/completion.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/clk.h>
> > +#include <linux/io.h>
> > +#include <linux/dma-mapping.h>
> > +
> > +#include <mach/platform.h>
> > +#include <mach/stmp3xxx.h>
> > +#include <mach/dma.h>
> > +#include <mach/regs-i2c.h>
> > +#include <mach/regs-apbx.h>
> > +
> > +static const struct stmp3xxx_dma_command cmd_i2c_select = {
> > +	.cmd =	BF(1, APBX_CHn_CMD_XFER_COUNT)	|
> > +		BF(1, APBX_CHn_CMD_CMDWORDS)	|
> > +		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
> > +		BM_APBX_CHn_CMD_CHAIN		|
> > +		BF(BV_APBX_CHn_CMD_COMMAND__DMA_READ, APBX_CHn_CMD_COMMAND),
> > +	.pio_words = {
> > +		[0] = 	BM_I2C_CTRL0_RETAIN_CLOCK   |
> > +			BM_I2C_CTRL0_PRE_SEND_START |
> > +			BM_I2C_CTRL0_MASTER_MODE    |
> > +			BM_I2C_CTRL0_DIRECTION      |
> > +			BF(1, I2C_CTRL0_XFER_COUNT),
> > +	},
> > +};
> > +
> > +static const struct stmp3xxx_dma_command cmd_i2c_write = {
> > +	.cmd =	BM_APBX_CHn_CMD_SEMAPHORE	|
> > +		BF(1, APBX_CHn_CMD_CMDWORDS)	|
> > +		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
> > +		BM_APBX_CHn_CMD_IRQONCMPLT	|
> > +		BF(BV_APBX_CHn_CMD_COMMAND__DMA_READ, APBX_CHn_CMD_COMMAND),
> > +	.pio_words = {
> > +		[0] =	BM_I2C_CTRL0_PRE_SEND_START |
> > +			BM_I2C_CTRL0_MASTER_MODE    |
> > +			BM_I2C_CTRL0_DIRECTION,
> > +	},
> > +};
> > +
> > +static const struct stmp3xxx_dma_command cmd_i2c_read = {
> > +	.cmd =	BM_APBX_CHn_CMD_SEMAPHORE	|
> > +		BF(1, APBX_CHn_CMD_CMDWORDS)	|
> > +		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
> > +		BM_APBX_CHn_CMD_IRQONCMPLT	|
> > +		BF(BV_APBX_CHn_CMD_COMMAND__DMA_WRITE, APBX_CHn_CMD_COMMAND),
> > +	.pio_words = {
> > +		[0] =	BM_I2C_CTRL0_SEND_NAK_ON_LAST	|
> > +			BM_I2C_CTRL0_MASTER_MODE,
> > +	},
> > +};
> > +
> > +/**
> > + * struct stmp378x_i2c_dev - STMP3xxx I2C adapter data
> > + * @dev: the associated platform_device
> > + * @cmd_complete: the completion structure indicating that message has been
> > + * 	transferred
> > + * @cmd_err: current error code
> > + * @adapter: the adapter we implement
> > + * @io: io address
> > + * @irq: irq number
> > + * @dma: dma channel
> > + * @bufv: pointer to the dma buffer
> > + * @bufp: physical address of the dma buffer
> > + * @i2c_dma_read: "read" dma chain (read request and then write)
> > + * @i2c_dma_write: "write" dma chain (the single combined write request)
> > + */
> > +struct stmp378x_i2c_dev {
> > +	struct device		*dev;
> > +	int			irq;
> > +	struct completion	cmd_complete;
> > +	u32			cmd_err;
> > +	struct i2c_adapter	adapter;
> > +	void __iomem 		*io;
> > +	unsigned		dma;
> > +
> > +	dma_addr_t		bufp;
> > +	unsigned char		*bufv;
> > +
> > +	struct stmp3xxx_dma_descriptor i2c_dma_read[2],
> > +				       i2c_dma_write;
> > +};
> > +
> > +static int stmp378x_i2c_init(struct stmp378x_i2c_dev *dev)
> > +{
> > +	int err;
> > +
> > +	err = stmp3xxx_dma_request(dev->dma, dev->dev, dev_name(dev->dev));
> > +	if (err)
> > +		goto out;
> > +	stmp3xxx_reset_block(dev->io, true);
> > +
> > +	dev->bufv = dma_alloc_coherent(dev->dev, PAGE_SIZE,
> > +				       &dev->bufp, GFP_KERNEL);
> > +	if (!dev->bufv)
> > +		goto out_dma;
> > +
> > +	err = stmp3xxx_request_pin_group(dev->dev->platform_data,
> > +			dev_name(dev->dev));
> > +	if (err)
> > +		goto out_free;
> > +
> > +	err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_read[0]);
> > +	if (err)
> > +		goto out_rd0;
> > +	err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_read[1]);
> > +	if (err)
> > +		goto out_rd1;
> > +	err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_write);
> > +	if (err)
> > +		goto out_wr;
> > +
> > +	stmp3xxx_dma_reset_channel(dev->dma);
> > +	stmp3xxx_dma_clear_interrupt(dev->dma);
> > +	stmp3xxx_dma_enable_interrupt(dev->dma);
> > +
> > +	return 0;
> > +/*
> > +	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_write);
> > +*/
> > +out_wr:
> > +	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[1]);
> > +out_rd1:
> > +	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[0]);
> > +out_rd0:
> > +	stmp3xxx_release_pin_group(dev->dev->platform_data, dev_name(dev->dev));
> > +out_free:
> > +	dma_free_coherent(dev->dev, PAGE_SIZE, dev->bufv, dev->bufp);
> > +out_dma:
> > +	stmp3xxx_dma_release(dev->dma);
> > +out:
> > +	return err;
> > +}
> > +
> > +static void stmp378x_i2c_release(struct stmp378x_i2c_dev *dev)
> > +{
> > +	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_write);
> > +	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[1]);
> > +	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[0]);
> > +	dma_free_coherent(dev->dev, PAGE_SIZE, dev->bufv, dev->bufp);
> > +	stmp3xxx_release_pin_group(dev->dev->platform_data, dev_name(dev->dev));
> > +	stmp3xxx_dma_release(dev->dma);
> > +}
> > +/*
> > + * Low level master read/write transaction.
> > + */
> > +static int stmp378x_i2c_xfer_msg(struct i2c_adapter *adap,
> > +				 struct i2c_msg *msg, int stop)
> > +{
> > +	struct stmp378x_i2c_dev *dev = i2c_get_adapdata(adap);
> > +	int err;
> > +	struct stmp3xxx_dma_descriptor *c, *r;
> > +
> > +	init_completion(&dev->cmd_complete);
> > +	dev->cmd_err = 0;
> > +
> > +	if ((msg->len == 0) || (msg->len > (PAGE_SIZE - 1)))
> > +		return -EINVAL;
> > +
> > +	if (msg->flags & I2C_M_RD) {
> > +
> > +		c = &dev->i2c_dma_read[0];
> > +		r = &dev->i2c_dma_read[1];
> > +
> > +		/* first, setup the SELECT command */
> > +		memcpy(c->command, &cmd_i2c_select, sizeof(cmd_i2c_select));
> > +		c->command->buf_ptr = dev->bufp;
> > +		dev->bufv[0] = msg->addr | I2C_SMBUS_READ;
> > +
> > +		/* then, setup the READ command */
> > +		memcpy(r->command, &cmd_i2c_read, sizeof(cmd_i2c_read));
> > +		r->command->cmd |= BF(msg->len, APBX_CHn_CMD_XFER_COUNT);
> > +		r->command->pio_words[0] |= BF(msg->len, I2C_CTRL0_XFER_COUNT);
> > +		if (stop)
> > +			r->command->pio_words[0] |= BM_I2C_CTRL0_POST_SEND_STOP;
> > +		/*
> > +		 * yes, STMP controller can DMA transfer the data from any
> > +		 * byte boundary
> > +		 */
> > +		r->command->buf_ptr = dev->bufp + 1;
> > +
> > +		/* and chain them together */
> > +		c->command->next = r->handle;
> > +
> > +	} else {
> > +
> > +		c = &dev->i2c_dma_write;
> > +		memcpy(c->command, &cmd_i2c_write, sizeof(cmd_i2c_write));
> > +		c->command->cmd |= BF(msg->len + 1, APBX_CHn_CMD_XFER_COUNT);
> > +		c->command->pio_words[0] |=
> > +				   BF(msg->len + 1, I2C_CTRL0_XFER_COUNT);
> > +		if (stop)
> > +			c->command->pio_words[0] |=
> > +				   BM_I2C_CTRL0_POST_SEND_STOP;
> > +		dev->bufv[0] = msg->addr | I2C_SMBUS_WRITE;
> > +		memcpy(dev->bufv + 1, msg->buf, msg->len);
> > +	}
> > +
> > +	stmp3xxx_dma_go(dev->dma, c, 1);
> > +
> > +	err = wait_for_completion_interruptible_timeout(&dev->cmd_complete,
> > +							msecs_to_jiffies(1000));
> > +
> > +	if (err < 0) {
> > +		dev_dbg(dev->dev, "controler is timed out\n");
> > +		return -ETIMEDOUT;
> > +	}
> > +	if (!dev->cmd_err && (msg->flags & I2C_M_RD))
> > +		memcpy(msg->buf, dev->bufv + 1, msg->len);
> > +
> > +	dev_dbg(dev->dev, "done with err=%d\n", dev->cmd_err);
> > +
> > +	return dev->cmd_err;
> > +}
> > +
> > +
> > +static int
> > +stmp378x_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
> > +{
> > +	int i;
> > +	int err;
> > +
> > +	if (!msgs->len)
> > +		return -EINVAL;
> > +
> > +	for (i = 0; i < num; i++) {
> > +		err = stmp378x_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
> > +		if (err)
> > +			return err;
> > +	}
> > +	return num;
> > +}
> > +
> > +static u32
> > +stmp378x_i2c_func(struct i2c_adapter *adap)
> > +{
> > +	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
> > +}
> > +
> > +#define I2C_IRQ_MASK 0x000000FF
> > +static irqreturn_t
> > +stmp378x_i2c_isr(int this_irq, void *dev_id)
> > +{
> > +	struct stmp378x_i2c_dev *dev = dev_id;
> > +	u32 stat;
> > +	u32 done_mask = BM_I2C_CTRL1_DATA_ENGINE_CMPLT_IRQ |
> > +			BM_I2C_CTRL1_BUS_FREE_IRQ ;
> > +
> > +	stat = readl(HW_I2C_CTRL1 + dev->io) & I2C_IRQ_MASK;
> > +	if (!stat)
> > +		return IRQ_NONE;
> > +
> > +	if (stat & BM_I2C_CTRL1_NO_SLAVE_ACK_IRQ) {
> > +		dev->cmd_err = -EREMOTEIO;
> > +
> > +		/*
> > +		 * Stop DMA
> > +		 * Clear NAK
> > +		 */
> > +		stmp3xxx_setl(BM_I2C_CTRL1_CLR_GOT_A_NAK,
> > +			      HW_I2C_CTRL1 + dev->io);
> > +		stmp3xxx_dma_reset_channel(dev->dma);
> > +		stmp3xxx_dma_clear_interrupt(dev->dma);
> > +
> > +		complete(&dev->cmd_complete);
> > +
> > +		goto done;
> > +	}
> > +
> > +	/* Don't care about  BM_I2C_CTRL1_OVERSIZE_XFER_TERM_IRQ */
> > +	if (stat & (BM_I2C_CTRL1_EARLY_TERM_IRQ |
> > +		    BM_I2C_CTRL1_MASTER_LOSS_IRQ |
> > +		    BM_I2C_CTRL1_SLAVE_STOP_IRQ |
> > +		    BM_I2C_CTRL1_SLAVE_IRQ)) {
> > +		dev->cmd_err = -EIO;
> > +		complete(&dev->cmd_complete);
> > +		goto done;
> > +	}
> > +
> > +	if ((stat & done_mask) == done_mask)
> > +		complete(&dev->cmd_complete);
> > +
> > +done:
> > +	stmp3xxx_clearl(stat, dev->io + HW_I2C_CTRL1);
> > +	return IRQ_HANDLED;
> > +}
> > +
> > +static const struct i2c_algorithm stmp378x_i2c_algo = {
> > +	.master_xfer	= stmp378x_i2c_xfer,
> > +	.functionality	= stmp378x_i2c_func,
> > +};
> > +
> > +
> > +static int __devinit
> > +stmp378x_i2c_probe(struct platform_device *pdev)
> > +{
> > +	struct stmp378x_i2c_dev	*dev;
> > +	struct i2c_adapter	*adap;
> > +	struct resource		*mem, *dma;
> > +	int err = 0;
> > +
> > +	dev = kzalloc(sizeof(struct stmp378x_i2c_dev), GFP_KERNEL);
> > +	if (!dev) {
> > +		dev_err(&pdev->dev, "no mem \n");
> > +		return -ENOMEM;
> > +	}
> > +
> > +	dev->irq = platform_get_irq(pdev, 0); /* Error */
> > +	if (dev->irq < 0) {
> > +		dev_err(&pdev->dev, "no err_irq resource\n");
> > +		err = dev->irq;
> > +		goto nores;
> > +	}
> > +
> > +	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +	if (!mem) {
> > +		dev_err(&pdev->dev, "no memory window\n");
> > +		err = -ENODEV;
> > +		goto nores;
> > +	}
> > +
> > +	dma = platform_get_resource(pdev, IORESOURCE_DMA, 0);
> > +	if (!dma) {
> > +		dev_err(&pdev->dev, "no dma channel\n");
> > +		err = -ENODEV;
> > +		goto nores;
> > +	}
> > +	dev->dma = dma->start;
> > +
> > +	dev->dev = &pdev->dev;
> > +	dev->io = ioremap(mem->start, resource_size(mem));
> > +	if (!dev->io) {
> > +		dev_err(&pdev->dev, "cannot ioremap\n");
> > +		err = -ENXIO;
> > +		goto nores;
> > +	}
> > +
> > +	err = request_irq(dev->irq, stmp378x_i2c_isr, 0, pdev->name, dev);
> > +	if (err) {
> > +		dev_err(&pdev->dev, "Can't get IRQ\n");
> > +		goto no_err_irq;
> > +	}
> > +
> > +	err = stmp378x_i2c_init(dev);
> > +	if (err) {
> > +		dev_err(&pdev->dev, "HW Init failed\n");
> > +		goto init_failed;
> > +	}
> > +
> > +	stmp3xxx_setl(0xFF00, dev->io + HW_I2C_CTRL1);
> > +
> > +	adap = &dev->adapter;
> > +	i2c_set_adapdata(adap, dev);
> > +	adap->owner = THIS_MODULE;
> > +	adap->class = I2C_CLASS_TV_DIGITAL;
> > +	strncpy(adap->name, "378x I2C adapter", sizeof(adap->name));
> > +	adap->algo = &stmp378x_i2c_algo;
> > +	adap->dev.parent = &pdev->dev;
> > +
> > +	adap->nr = pdev->id;
> > +	err = i2c_add_numbered_adapter(adap);
> > +	if (err) {
> > +		dev_err(&pdev->dev, "Failed to add adapter\n");
> > +		goto no_i2c_adapter;
> > +
> > +	}
> > +
> > +	return 0;
> > +
> > +no_i2c_adapter:
> > +	stmp378x_i2c_release(dev);
> > +init_failed:
> > +	free_irq(dev->irq, dev);
> > +no_err_irq:
> > +	iounmap(dev->io);
> > +nores:
> > +	kfree(dev);
> > +	return err;
> > +}
> > +
> > +static int __devexit
> > +stmp378x_i2c_remove(struct platform_device *pdev)
> > +{
> > +	struct stmp378x_i2c_dev	*dev = platform_get_drvdata(pdev);
> > +	int res;
> > +
> > +	res = i2c_del_adapter(&dev->adapter);
> > +	if (res)
> > +		return -EBUSY;
> > +
> > +	stmp378x_i2c_release(dev);
> > +
> > +	platform_set_drvdata(pdev, NULL);
> > +
> > +	free_irq(dev->irq, dev);
> > +	iounmap(dev->io);
> > +
> > +	kfree(dev);
> > +	return 0;
> > +}
> > +
> > +static struct platform_driver stmp378x_i2c_driver = {
> > +	.probe		= stmp378x_i2c_probe,
> > +	.remove		= __devexit_p(stmp378x_i2c_remove),
> > +	.driver		= {
> > +		.name	= "i2c_stmp3xxx",
> > +		.owner	= THIS_MODULE,
> > +	},
> > +};
> > +
> > +static int __init stmp378x_i2c_init_driver(void)
> > +{
> > +	return platform_driver_register(&stmp378x_i2c_driver);
> > +}
> > +module_init(stmp378x_i2c_init_driver);
> > +
> > +static void __exit stmp378x_i2c_exit_driver(void)
> > +{
> > +	platform_driver_unregister(&stmp378x_i2c_driver);
> > +}
> > +module_exit(stmp378x_i2c_exit_driver);
> > +
> > +MODULE_AUTHOR("d.frasenyak-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org");
> > +MODULE_DESCRIPTION("I2C for Freescale STMP378x");
> > +MODULE_LICENSE("GPL");
> > +MODULE_ALIAS("platform:i2c_stmp3xxx");
> > 
> > 
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
> > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

Re: [PATCH, RFC] Freescale STMP: i2c driver, updated with correct signed-off lines

[dmitry pervushin]

On Mon, 2009-06-22 at 01:47 +0100, Ben Dooks wrote:
> On Tue, Jun 16, 2009 at 08:31:53PM +0400, dmitry pervushin wrote:
> > On Mon, 2009-06-15 at 09:19 +0100, Ben Dooks wrote:
> > > any chance of an reply or update driver for inclusion?
> > Here it is:

Add I2C driver for Freescale STMP boards

From: Dmitrij Frasenyak <d.frasenyak-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org> 
Signed-off-by: Dmitrij Frasenyak <d.frasenyak-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
Signed-off-by: dmitry pervushin <dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>

---
 drivers/i2c/busses/Kconfig        |    7 
 drivers/i2c/busses/Makefile       |    1 
 drivers/i2c/busses/i2c-stmp378x.c |  450 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 458 insertions(+)

Index: linux-2.6-arm/drivers/i2c/busses/Kconfig
===================================================================
--- linux-2.6-arm.orig/drivers/i2c/busses/Kconfig
+++ linux-2.6-arm/drivers/i2c/busses/Kconfig
@@ -513,6 +513,13 @@ config I2C_SIMTEC
 	  This driver can also be built as a module. If so, the module
 	  will be called i2c-simtec.
 
+config I2C_STMP378X
+	tristate "STMP378x I2C adapter"
+	depends on ARCH_STMP378X
+	help
+	  Include support of I2C adapter on Freescale STMP378x board; to build
+	  the driver as a module, say M here - module will be called i2c-stmp378x.
+
 config I2C_VERSATILE
 	tristate "ARM Versatile/Realview I2C bus support"
 	depends on ARCH_VERSATILE || ARCH_REALVIEW
Index: linux-2.6-arm/drivers/i2c/busses/Makefile
===================================================================
--- linux-2.6-arm.orig/drivers/i2c/busses/Makefile
+++ linux-2.6-arm/drivers/i2c/busses/Makefile
@@ -48,6 +48,7 @@ obj-$(CONFIG_I2C_S6000)		+= i2c-s6000.o
 obj-$(CONFIG_I2C_SH7760)	+= i2c-sh7760.o
 obj-$(CONFIG_I2C_SH_MOBILE)	+= i2c-sh_mobile.o
 obj-$(CONFIG_I2C_SIMTEC)	+= i2c-simtec.o
+obj-$(CONFIG_I2C_STMP378X)	+= i2c-stmp378x.o
 obj-$(CONFIG_I2C_VERSATILE)	+= i2c-versatile.o
 
 # External I2C/SMBus adapter drivers
Index: linux-2.6-arm/drivers/i2c/busses/i2c-stmp378x.c
===================================================================
--- /dev/null
+++ linux-2.6-arm/drivers/i2c/busses/i2c-stmp378x.c
@@ -0,0 +1,450 @@
+/*
+ * Freescale STMP378X I2C bus driver
+ *
+ * Author: Dmitrij Frasenyak <sed-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
+ *
+ * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/completion.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
+
+#include <mach/platform.h>
+#include <mach/stmp3xxx.h>
+#include <mach/dma.h>
+#include <mach/regs-i2c.h>
+#include <mach/regs-apbx.h>
+
+static const struct stmp3xxx_dma_command cmd_i2c_select = {
+	.cmd =	(1 << BP_APBX_CHn_CMD_XFER_COUNT)	|
+		(1 << BP_APBX_CHn_CMD_CMDWORDS)	|
+		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
+		BM_APBX_CHn_CMD_CHAIN		|
+		(BV_APBX_CHn_CMD_COMMAND__DMA_READ << BP_APBX_CHn_CMD_COMMAND),
+	.pio_words = {
+		[0] = 	BM_I2C_CTRL0_RETAIN_CLOCK   |
+			BM_I2C_CTRL0_PRE_SEND_START |
+			BM_I2C_CTRL0_MASTER_MODE    |
+			BM_I2C_CTRL0_DIRECTION      |
+			(1 << BP_I2C_CTRL0_XFER_COUNT),
+	},
+};
+
+static const struct stmp3xxx_dma_command cmd_i2c_write = {
+	.cmd =	BM_APBX_CHn_CMD_SEMAPHORE	|
+		(1 << BP_APBX_CHn_CMD_CMDWORDS)	|
+		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
+		BM_APBX_CHn_CMD_IRQONCMPLT	|
+		(BV_APBX_CHn_CMD_COMMAND__DMA_READ << BP_APBX_CHn_CMD_COMMAND),
+	.pio_words = {
+		[0] =	BM_I2C_CTRL0_PRE_SEND_START |
+			BM_I2C_CTRL0_MASTER_MODE    |
+			BM_I2C_CTRL0_DIRECTION,
+	},
+};
+
+static const struct stmp3xxx_dma_command cmd_i2c_read = {
+	.cmd =	BM_APBX_CHn_CMD_SEMAPHORE	|
+		(1 << BP_APBX_CHn_CMD_CMDWORDS)	|
+		BM_APBX_CHn_CMD_WAIT4ENDCMD	|
+		BM_APBX_CHn_CMD_IRQONCMPLT	|
+		(BV_APBX_CHn_CMD_COMMAND__DMA_WRITE << BP_APBX_CHn_CMD_COMMAND),
+	.pio_words = {
+		[0] =	BM_I2C_CTRL0_SEND_NAK_ON_LAST	|
+			BM_I2C_CTRL0_MASTER_MODE,
+	},
+};
+
+/**
+ * struct stmp378x_i2c_dev - STMP3xxx I2C adapter data
+ * @dev: the associated platform_device
+ * @cmd_complete: the completion structure indicating that message has been
+ * 	transferred
+ * @cmd_err: current error code
+ * @adapter: the adapter we implement
+ * @io: io address
+ * @irq: irq number
+ * @dma: dma channel
+ * @bufv: pointer to the dma buffer
+ * @bufp: physical address of the dma buffer
+ * @i2c_dma_read: "read" dma chain (read request and then write)
+ * @i2c_dma_write: "write" dma chain (the single combined write request)
+ */
+struct stmp378x_i2c_dev {
+	struct device		*dev;
+	int			irq;
+	struct completion	cmd_complete;
+	u32			cmd_err;
+	struct i2c_adapter	adapter;
+	void __iomem 		*io;
+	unsigned		dma;
+
+	dma_addr_t		bufp;
+	unsigned char		*bufv;
+
+	struct stmp3xxx_dma_descriptor i2c_dma_read[2],
+				       i2c_dma_write;
+};
+
+static int stmp378x_i2c_init(struct stmp378x_i2c_dev *dev)
+{
+	int err;
+
+	err = stmp3xxx_dma_request(dev->dma, dev->dev, dev_name(dev->dev));
+	if (err)
+		goto out;
+	stmp3xxx_reset_block(dev->io, true);
+
+	dev->bufv = dma_alloc_coherent(dev->dev, PAGE_SIZE,
+				       &dev->bufp, GFP_KERNEL);
+	if (!dev->bufv)
+		goto out_dma;
+
+	err = stmp3xxx_request_pin_group(dev->dev->platform_data,
+			dev_name(dev->dev));
+	if (err)
+		goto out_free;
+
+	err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_read[0]);
+	if (err)
+		goto out_rd0;
+	err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_read[1]);
+	if (err)
+		goto out_rd1;
+	err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_write);
+	if (err)
+		goto out_wr;
+
+	stmp3xxx_dma_reset_channel(dev->dma);
+	stmp3xxx_dma_clear_interrupt(dev->dma);
+	stmp3xxx_dma_enable_interrupt(dev->dma);
+
+	return 0;
+/*
+	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_write);
+*/
+out_wr:
+	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[1]);
+out_rd1:
+	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[0]);
+out_rd0:
+	stmp3xxx_release_pin_group(dev->dev->platform_data, dev_name(dev->dev));
+out_free:
+	dma_free_coherent(dev->dev, PAGE_SIZE, dev->bufv, dev->bufp);
+out_dma:
+	stmp3xxx_dma_release(dev->dma);
+out:
+	return err;
+}
+
+static void stmp378x_i2c_release(struct stmp378x_i2c_dev *dev)
+{
+	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_write);
+	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[1]);
+	stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[0]);
+	dma_free_coherent(dev->dev, PAGE_SIZE, dev->bufv, dev->bufp);
+	stmp3xxx_release_pin_group(dev->dev->platform_data, dev_name(dev->dev));
+	stmp3xxx_dma_release(dev->dma);
+}
+/*
+ * Low level master read/write transaction.
+ */
+static int stmp378x_i2c_xfer_msg(struct i2c_adapter *adap,
+				 struct i2c_msg *msg, int stop)
+{
+	struct stmp378x_i2c_dev *dev = i2c_get_adapdata(adap);
+	int err;
+	struct stmp3xxx_dma_descriptor *c, *r;
+
+	init_completion(&dev->cmd_complete);
+	dev->cmd_err = 0;
+
+	if ((msg->len == 0) || (msg->len > (PAGE_SIZE - 1)))
+		return -EINVAL;
+
+	if (msg->flags & I2C_M_RD) {
+
+		c = &dev->i2c_dma_read[0];
+		r = &dev->i2c_dma_read[1];
+
+		/* first, setup the SELECT command */
+		memcpy(c->command, &cmd_i2c_select, sizeof(cmd_i2c_select));
+		c->command->buf_ptr = dev->bufp;
+		dev->bufv[0] = msg->addr | I2C_SMBUS_READ;
+
+		/* then, setup the READ command */
+		memcpy(r->command, &cmd_i2c_read, sizeof(cmd_i2c_read));
+		r->command->cmd |= (msg->len << BP_APBX_CHn_CMD_XFER_COUNT);
+		r->command->pio_words[0] |=
+				(msg->len << BP_I2C_CTRL0_XFER_COUNT);
+		if (stop)
+			r->command->pio_words[0] |= BM_I2C_CTRL0_POST_SEND_STOP;
+		/*
+		 * yes, STMP controller can DMA transfer the data from any
+		 * byte boundary
+		 */
+		r->command->buf_ptr = dev->bufp + 1;
+
+		/* and chain them together */
+		c->command->next = r->handle;
+
+	} else {
+
+		c = &dev->i2c_dma_write;
+		memcpy(c->command, &cmd_i2c_write, sizeof(cmd_i2c_write));
+		c->command->cmd |=
+				((msg->len + 1) << BP_APBX_CHn_CMD_XFER_COUNT);
+		c->command->pio_words[0] |=
+				((msg->len + 1) << BP_I2C_CTRL0_XFER_COUNT);
+		if (stop)
+			c->command->pio_words[0] |=
+				   BM_I2C_CTRL0_POST_SEND_STOP;
+		dev->bufv[0] = msg->addr | I2C_SMBUS_WRITE;
+		memcpy(dev->bufv + 1, msg->buf, msg->len);
+	}
+
+	stmp3xxx_dma_go(dev->dma, c, 1);
+
+	err = wait_for_completion_interruptible_timeout(&dev->cmd_complete,
+							msecs_to_jiffies(1000));
+
+	if (err < 0) {
+		dev_dbg(dev->dev, "controler is timed out\n");
+		return -ETIMEDOUT;
+	}
+	if (!dev->cmd_err && (msg->flags & I2C_M_RD))
+		memcpy(msg->buf, dev->bufv + 1, msg->len);
+
+	dev_dbg(dev->dev, "done with err=%d\n", dev->cmd_err);
+
+	return dev->cmd_err;
+}
+
+
+static int
+stmp378x_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
+{
+	int i;
+	int err;
+
+	if (!msgs->len)
+		return -EINVAL;
+
+	for (i = 0; i < num; i++) {
+		err = stmp378x_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
+		if (err)
+			return err;
+	}
+	return num;
+}
+
+static u32
+stmp378x_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+}
+
+#define I2C_IRQ_MASK 0x000000FF
+static irqreturn_t
+stmp378x_i2c_isr(int this_irq, void *dev_id)
+{
+	struct stmp378x_i2c_dev *dev = dev_id;
+	u32 stat;
+	u32 done_mask = BM_I2C_CTRL1_DATA_ENGINE_CMPLT_IRQ |
+			BM_I2C_CTRL1_BUS_FREE_IRQ ;
+
+	stat = readl(HW_I2C_CTRL1 + dev->io) & I2C_IRQ_MASK;
+	if (!stat)
+		return IRQ_NONE;
+
+	if (stat & BM_I2C_CTRL1_NO_SLAVE_ACK_IRQ) {
+		dev->cmd_err = -EREMOTEIO;
+
+		/*
+		 * Stop DMA
+		 * Clear NAK
+		 */
+		stmp3xxx_setl(BM_I2C_CTRL1_CLR_GOT_A_NAK,
+			      HW_I2C_CTRL1 + dev->io);
+		stmp3xxx_dma_reset_channel(dev->dma);
+		stmp3xxx_dma_clear_interrupt(dev->dma);
+
+		complete(&dev->cmd_complete);
+
+		goto done;
+	}
+
+	/* Don't care about  BM_I2C_CTRL1_OVERSIZE_XFER_TERM_IRQ */
+	if (stat & (BM_I2C_CTRL1_EARLY_TERM_IRQ |
+		    BM_I2C_CTRL1_MASTER_LOSS_IRQ |
+		    BM_I2C_CTRL1_SLAVE_STOP_IRQ |
+		    BM_I2C_CTRL1_SLAVE_IRQ)) {
+		dev->cmd_err = -EIO;
+		complete(&dev->cmd_complete);
+		goto done;
+	}
+
+	if ((stat & done_mask) == done_mask)
+		complete(&dev->cmd_complete);
+
+done:
+	stmp3xxx_clearl(stat, dev->io + HW_I2C_CTRL1);
+	return IRQ_HANDLED;
+}
+
+static const struct i2c_algorithm stmp378x_i2c_algo = {
+	.master_xfer	= stmp378x_i2c_xfer,
+	.functionality	= stmp378x_i2c_func,
+};
+
+
+static int __devinit
+stmp378x_i2c_probe(struct platform_device *pdev)
+{
+	struct stmp378x_i2c_dev	*dev;
+	struct i2c_adapter	*adap;
+	struct resource		*mem, *dma;
+	int err = 0;
+
+	dev = kzalloc(sizeof(struct stmp378x_i2c_dev), GFP_KERNEL);
+	if (!dev) {
+		dev_err(&pdev->dev, "no mem \n");
+		return -ENOMEM;
+	}
+
+	dev->irq = platform_get_irq(pdev, 0); /* Error */
+	if (dev->irq < 0) {
+		dev_err(&pdev->dev, "no err_irq resource\n");
+		err = dev->irq;
+		goto nores;
+	}
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mem) {
+		dev_err(&pdev->dev, "no memory window\n");
+		err = -ENODEV;
+		goto nores;
+	}
+
+	dma = platform_get_resource(pdev, IORESOURCE_DMA, 0);
+	if (!dma) {
+		dev_err(&pdev->dev, "no dma channel\n");
+		err = -ENODEV;
+		goto nores;
+	}
+	dev->dma = dma->start;
+
+	dev->dev = &pdev->dev;
+	dev->io = ioremap(mem->start, resource_size(mem));
+	if (!dev->io) {
+		dev_err(&pdev->dev, "cannot ioremap\n");
+		err = -ENXIO;
+		goto nores;
+	}
+
+	err = request_irq(dev->irq, stmp378x_i2c_isr, 0, pdev->name, dev);
+	if (err) {
+		dev_err(&pdev->dev, "Can't get IRQ\n");
+		goto no_err_irq;
+	}
+
+	err = stmp378x_i2c_init(dev);
+	if (err) {
+		dev_err(&pdev->dev, "HW Init failed\n");
+		goto init_failed;
+	}
+
+	stmp3xxx_setl(0xFF00, dev->io + HW_I2C_CTRL1);
+
+	adap = &dev->adapter;
+	i2c_set_adapdata(adap, dev);
+	adap->owner = THIS_MODULE;
+	adap->class = I2C_CLASS_TV_DIGITAL;
+	strncpy(adap->name, "378x I2C adapter", sizeof(adap->name));
+	adap->algo = &stmp378x_i2c_algo;
+	adap->dev.parent = &pdev->dev;
+
+	adap->nr = pdev->id;
+	err = i2c_add_numbered_adapter(adap);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to add adapter\n");
+		goto no_i2c_adapter;
+
+	}
+
+	return 0;
+
+no_i2c_adapter:
+	stmp378x_i2c_release(dev);
+init_failed:
+	free_irq(dev->irq, dev);
+no_err_irq:
+	iounmap(dev->io);
+nores:
+	kfree(dev);
+	return err;
+}
+
+static int __devexit
+stmp378x_i2c_remove(struct platform_device *pdev)
+{
+	struct stmp378x_i2c_dev	*dev = platform_get_drvdata(pdev);
+	int res;
+
+	res = i2c_del_adapter(&dev->adapter);
+	if (res)
+		return -EBUSY;
+
+	stmp378x_i2c_release(dev);
+
+	platform_set_drvdata(pdev, NULL);
+
+	free_irq(dev->irq, dev);
+	iounmap(dev->io);
+
+	kfree(dev);
+	return 0;
+}
+
+static struct platform_driver stmp378x_i2c_driver = {
+	.probe		= stmp378x_i2c_probe,
+	.remove		= __devexit_p(stmp378x_i2c_remove),
+	.driver		= {
+		.name	= "i2c_stmp3xxx",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init stmp378x_i2c_init_driver(void)
+{
+	return platform_driver_register(&stmp378x_i2c_driver);
+}
+module_init(stmp378x_i2c_init_driver);
+
+static void __exit stmp378x_i2c_exit_driver(void)
+{
+	platform_driver_unregister(&stmp378x_i2c_driver);
+}
+module_exit(stmp378x_i2c_exit_driver);
+
+MODULE_AUTHOR("d.frasenyak-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org");
+MODULE_DESCRIPTION("I2C for Freescale STMP378x");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:i2c_stmp3xxx");