RE: [PATCH] i2c: cyttsp i2c and spi touchscreen driver init submit

["Kevin McNeely" <Kevin.McNeely@cypress.com>]

Hi Trilok,

> -----Original Message-----
> From: Trilok Soni [mailto:tsoni@codeaurora.org]
> Sent: Friday, August 06, 2010 2:07 AM
> To: Kevin McNeely
> Cc: Dmitry Torokhov; David Brown; Samuel Ortiz; Eric Miao; Ben Dooks;
> Simtec Linux Team; Todd Fischer; Arnaud Patard; Sascha Hauer; Henrik
> Rydberg; linux-input@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH] i2c: cyttsp i2c and spi touchscreen driver init
> submit
> 
> Hi Kevin,
> 
> Review for SPI code.
> 
> > diff --git a/drivers/input/touchscreen/cyttsp_spi.c
> b/drivers/input/touchscreen/cyttsp_spi.c
> > new file mode 100755
> 
> 
> > +#include <linux/init.h>
> > +#include <linux/module.h>
> > +#include <linux/spi/spi.h>
> > +#include <linux/delay.h>
> > +#include <linux/cyttsp.h>
> > +#include "cyttsp_core.h"
> > +
> > +#define DBG(x)
> > +
> > +#define CY_SPI_WR_OP      0x00 /* r/~w */
> > +#define CY_SPI_RD_OP      0x01
> > +#define CY_SPI_CMD_BYTES  4
> > +#define CY_SPI_SYNC_BYTES 2
> > +#define CY_SPI_SYNC_ACK1  0x62 /* from protocol v.2 */
> > +#define CY_SPI_SYNC_ACK2  0x9D /* from protocol v.2 */
> > +#define CY_SPI_SYNC_NACK  0x69
> > +#define CY_SPI_DATA_SIZE  64
> > +#define CY_SPI_DATA_BUF_SIZE (CY_SPI_CMD_BYTES + CY_SPI_DATA_SIZE)
> > +#define CY_SPI_BITS_PER_WORD 8
> > +
> > +struct cyttsp_spi {
> > +	struct cyttsp_bus_ops ops;
> > +	struct spi_device *spi_client;
> > +	void *ttsp_client;
> > +	u8 wr_buf[CY_SPI_DATA_BUF_SIZE];
> > +	u8 rd_buf[CY_SPI_DATA_BUF_SIZE];
> > +};
> > +
> > +static void spi_complete(void *arg)
> > +{
> > +	complete(arg);
> 
> We don't need anything here on completion?

No, nothing needed.

> 
> > +}
> > +
> > +static int spi_sync_tmo(struct spi_device *spi, struct spi_message
> *message)
> > +{
> > +	DECLARE_COMPLETION_ONSTACK(done);
> > +	int status;
> > +	DBG(printk(KERN_INFO"%s: Enter\n", __func__);)
> 
> No need.

Will remove.

> 
> > +
> > +	message->complete = spi_complete;
> > +	message->context = &done;
> > +	status = spi_async(spi, message);
> > +	if (status == 0) {
> > +		int ret =
wait_for_completion_interruptible_timeout(&done,
> HZ);
> > +		if (!ret) {
> > +			printk(KERN_ERR "%s: timeout\n", __func__);
> > +			status = -EIO;
> > +		} else
> > +			status = message->status;
> > +	}
> > +	message->context = NULL;
> > +	return status;
> > +}
> > +
> > +static int cyttsp_spi_xfer_(u8 op, struct cyttsp_spi *ts_spi,
> > +			    u8 reg, u8 *buf, int length)
> > +{
> > +	struct spi_message msg;
> > +	struct spi_transfer xfer = { 0 };
> > +	u8 *wr_buf = ts_spi->wr_buf;
> > +	u8 *rd_buf = ts_spi->rd_buf;
> > +	int retval;
> > +	int i;
> > +	DBG(printk(KERN_INFO "%s: Enter\n", __func__);)
> 
> No need.

Will remove.

> 
> > +
> > +	if (length > CY_SPI_DATA_SIZE) {
> > +		printk(KERN_ERR "%s: length %d is too big.\n",
> > +			__func__, length);
> > +		return -EINVAL;
> > +	}
> > +	DBG(printk(KERN_INFO "%s: OP=%s length=%d\n", __func__,
> > +		   op == CY_SPI_RD_OP ? "Read" : "Write", length);)
> 
> dev_dbg if really needed.

Will use dev_dbg where needed.

> 
> > +
> > +	wr_buf[0] = 0x00; /* header byte 0 */
> > +	wr_buf[1] = 0xFF; /* header byte 1 */
> > +	wr_buf[2] = reg;  /* reg index */
> > +	wr_buf[3] = op;   /* r/~w */
> > +	if (op == CY_SPI_WR_OP)
> > +		memcpy(wr_buf + CY_SPI_CMD_BYTES, buf, length);
> > +	DBG(
> > +	if (op == CY_SPI_RD_OP)
> > +		memset(rd_buf, CY_SPI_SYNC_NACK, CY_SPI_DATA_BUF_SIZE);)
> > +	DBG(
> > +	for (i = 0; i < (length + CY_SPI_CMD_BYTES); i++) {
> > +		if ((op == CY_SPI_RD_OP) && (i < CY_SPI_CMD_BYTES))
> > +			printk(KERN_INFO "%s: wr[%d]:0x%02x\n",
> > +				__func__, i, wr_buf[i]);
> > +		if (op == CY_SPI_WR_OP)
> > +			printk(KERN_INFO "%s: wr[%d]:0x%02x\n",
> > +				__func__, i, wr_buf[i]);
> > +	})
> 
> Let remove such things.

Will do.

> 
> > +
> > +	xfer.tx_buf = wr_buf;
> > +	xfer.rx_buf = rd_buf;
> > +	xfer.len = length + CY_SPI_CMD_BYTES;
> > +
> > +	if ((op == CY_SPI_RD_OP) && (xfer.len < 32))
> > +		xfer.len += 1;
> > +
> > +	spi_message_init(&msg);
> > +	spi_message_add_tail(&xfer, &msg);
> > +	retval = spi_sync_tmo(ts_spi->spi_client, &msg);
> > +	if (retval < 0) {
> > +		printk(KERN_ERR "%s: spi_sync_tmo() error %d\n",
> > +			__func__, retval);
> > +		retval = 0;
> > +	}
> > +	if (op == CY_SPI_RD_OP) {
> > +		DBG(
> > +		for (i = 0; i < (length + CY_SPI_CMD_BYTES); i++)
> > +			printk(KERN_INFO "%s: rd[%d]:0x%02x\n",
> > +				__func__, i, rd_buf[i]);)
> > +
> > +		for (i = 0; i < (length + CY_SPI_CMD_BYTES - 1); i++) {
> > +			if ((rd_buf[i] != CY_SPI_SYNC_ACK1) ||
> > +				(rd_buf[i + 1] != CY_SPI_SYNC_ACK2)) {
> > +				continue;
> > +			}
> > +			if (i <= (CY_SPI_CMD_BYTES - 1)) {
> > +				memcpy(buf, (rd_buf + i +
CY_SPI_SYNC_BYTES),
> > +					length);
> > +				return 0;
> > +			}
> > +		}
> > +		DBG(printk(KERN_INFO "%s: byte sync error\n",
__func__);)
> 
> dev_err if you really need to print for debugging purpose or
> pr_err(...)
> 
> > +		retval = 1;
> > +	}
> > +	return retval;
> > +}
> > +
> > +static int cyttsp_spi_xfer(u8 op, struct cyttsp_spi *ts,
> > +			    u8 reg, u8 *buf, int length)
> > +{
> > +	int tries;
> > +	int retval;
> > +	DBG(printk(KERN_INFO "%s: Enter\n", __func__);)
> 
> No need.

Will remove.

> 
> > +
> > +	if (op == CY_SPI_RD_OP) {
> > +		for (tries = CY_NUM_RETRY; tries; tries--) {
> > +			retval = cyttsp_spi_xfer_(op, ts, reg, buf,
length);
> > +			if (retval == 0)
> > +				break;
> > +			else
> > +				msleep(10);
> > +		}
> > +	} else {
> > +		retval = cyttsp_spi_xfer_(op, ts, reg, buf, length);
> > +	}
> > +	return retval;
> > +}
> > +
> > +static s32 ttsp_spi_read_block_data(void *handle, u8 addr,
> > +				    u8 length, void *data)
> > +{
> > +	int retval;
> > +	struct cyttsp_spi *ts = container_of(handle, struct cyttsp_spi,
> ops);
> > +
> > +	DBG(printk(KERN_INFO "%s: Enter\n", __func__);)
> 
> No need.

Will remove.

> 
> > +
> > +	retval = cyttsp_spi_xfer(CY_SPI_RD_OP, ts, addr, data, length);
> > +	if (retval < 0)
> > +		printk(KERN_ERR "%s: ttsp_spi_read_block_data failed\n",
> > +			__func__);
> 
> dev_err(...)
> 
> > +
> > +	/* Do not print the above error if the data sync bytes were not
> found.
> > +	   This is a normal condition for the bootloader loader startup
> and need
> > +	   to retry until data sync bytes are found. */
> 
> Use kernel style for multi-line comments.
> 
> 
> /*
>  * You should use this format
>  * for multi-line commenting
>  */
>

Will do for all.
 
> 
> 
> > +	if (retval > 0)
> > +		retval = -1;	/* now signal fail; so retry can be done
> */
> > +
> > +	return retval;
> > +}
> > +
> > +static s32 ttsp_spi_write_block_data(void *handle, u8 addr,
> > +				     u8 length, const void *data)
> > +{
> > +	int retval;
> > +	struct cyttsp_spi *ts = container_of(handle, struct cyttsp_spi,
> ops);
> > +
> > +	DBG(printk(KERN_INFO "%s: Enter\n", __func__);)
> 
> No need.

Will remove.

> 
> > +
> > +	retval = cyttsp_spi_xfer(CY_SPI_WR_OP, ts, addr, (void *)data,
> length);
> > +	if (retval < 0)
> > +		printk(KERN_ERR "%s: ttsp_spi_write_block_data
failed\n",
> > +			__func__);
> > +
> > +	if (retval == -EIO)
> > +		return 0;
> > +	else
> > +		return retval;
> > +}
> > +
> > +static s32 ttsp_spi_tch_ext(void *handle, void *values)
> > +{
> > +	int retval = 0;
> > +	struct cyttsp_spi *ts = container_of(handle, struct cyttsp_spi,
> ops);
> > +
> > +	DBG(printk(KERN_INFO "%s: Enter\n", __func__);)
> 
> No need.

Will remove.

> 
> > +
> > +	/* Add custom touch extension handling code here */
> 
> You may want to add this as "TODO".
> 
> > +	/* set: retval < 0 for any returned system errors,
> > +		retval = 0 if normal touch handling is required,
> > +		retval > 0 if normal touch handling is *not* required */
> > +	if (!ts || !values)
> > +		retval = -EIO;
> > +
> > +	return retval;
> > +}
> > +
> > +static int __devinit cyttsp_spi_probe(struct spi_device *spi)
> > +{
> > +	struct cyttsp_spi *ts_spi;
> > +	int retval;
> > +	DBG(printk(KERN_INFO"%s: Enter\n", __func__);)
> 
> Un-necessary printk.

Will remove.

> 
> > +
> > +	/* Set up SPI*/
> > +	spi->bits_per_word = CY_SPI_BITS_PER_WORD;
> > +	spi->mode = SPI_MODE_0;
> > +	retval = spi_setup(spi);
> > +	if (retval < 0) {
> > +		printk(KERN_ERR "%s: SPI setup error %d\n", __func__,
> retval);
> 
> dev_err(...)

Will replace all printk with appropriate dev_xxx(...).

> 
> > +		return retval;
> > +	}
> > +	ts_spi = kzalloc(sizeof(*ts_spi), GFP_KERNEL);
> > +	if (ts_spi == NULL) {
> > +		printk(KERN_ERR "%s: Error, kzalloc\n", __func__);
> 
> dev_err(...)

Will replace.

> 
> > +		retval = -ENOMEM;
> > +		goto error_alloc_data_failed;
> > +	}
> > +	ts_spi->spi_client = spi;
> > +	dev_set_drvdata(&spi->dev, ts_spi);
> > +	ts_spi->ops.write = ttsp_spi_write_block_data;
> > +	ts_spi->ops.read = ttsp_spi_read_block_data;
> > +	ts_spi->ops.ext = ttsp_spi_tch_ext;
> > +
> > +	ts_spi->ttsp_client = cyttsp_core_init(&ts_spi->ops, &spi->dev);
> > +	if (!ts_spi->ttsp_client)
> > +		goto ttsp_core_err;
> > +	printk(KERN_INFO "%s: Successful registration %s\n",
> > +	       __func__, CY_SPI_NAME);
> 
> 
> > +
> > +	return 0;
> > +
> > +ttsp_core_err:
> > +	kfree(ts_spi);
> > +error_alloc_data_failed:
> > +	return retval;
> > +}
> > +
> > +/* registered in driver struct */
> 
> No need.

Sorry, this is unclear.

> 
> > +static int __devexit cyttsp_spi_remove(struct spi_device *spi)
> > +{
> > +	struct cyttsp_spi *ts_spi = dev_get_drvdata(&spi->dev);
> > +	DBG(printk(KERN_INFO"%s: Enter\n", __func__);)
> 
> Remove this printk.

Will do.

> 
> > +	cyttsp_core_release(ts_spi->ttsp_client);
> > +	kfree(ts_spi);
> > +	return 0;
> > +}
> > +
> > +#ifdef CONFIG_PM
> > +static int cyttsp_spi_suspend(struct spi_device *spi, pm_message_t
> message)
> > +{
> > +	return cyttsp_suspend(dev_get_drvdata(&spi->dev));
> > +}
> > +
> > +static int cyttsp_spi_resume(struct spi_device *spi)
> > +{
> > +	return cyttsp_resume(dev_get_drvdata(&spi->dev));
> > +}
> > +#endif
> > +
> > +static struct spi_driver cyttsp_spi_driver = {
> > +	.driver = {
> > +		.name = CY_SPI_NAME,
> > +		.bus = &spi_bus_type,
> > +		.owner = THIS_MODULE,
> > +	},
> > +	.probe = cyttsp_spi_probe,
> > +	.remove = __devexit_p(cyttsp_spi_remove),
> > +#ifdef CONFIG_PM
> > +	.suspend = cyttsp_spi_suspend,
> > +	.resume = cyttsp_spi_resume,
> > +#endif
> > +};
> > +
> > +static int __init cyttsp_spi_init(void)
> > +{
> > +	int err;
> > +
> > +	err = spi_register_driver(&cyttsp_spi_driver);
> > +	printk(KERN_INFO "%s: Cypress TrueTouch(R) Standard Product SPI
"
> > +		"Touchscreen Driver (Built %s @ %s) returned %d\n",
> > +		 __func__, __DATE__, __TIME__, err);
> 
> As Dmitry mentioned on another e-mail, remove such printks. They
create
> un-necessary noise.

Will remove.

> 
> > +
> > +	return err;
> > +}
> > +module_init(cyttsp_spi_init);
> > +
> > +static void __exit cyttsp_spi_exit(void)
> > +{
> > +	spi_unregister_driver(&cyttsp_spi_driver);
> > +	printk(KERN_INFO "%s: module exit\n", __func__);
> 
> Ditto.

Will remove.

> 
> > +}
> > +module_exit(cyttsp_spi_exit);
> > +
> > +MODULE_ALIAS("spi:cyttsp");
> > +MODULE_LICENSE("GPL");
> > +MODULE_DESCRIPTION("Cypress TrueTouch(R) Standard Product (TTSP)
SPI
> driver");
> > +MODULE_AUTHOR("Cypress");
> > +
> > diff --git a/include/linux/cyttsp.h b/include/linux/cyttsp.h
> > new file mode 100755
> > index 0000000..b2a289b
> > --- /dev/null
> > +++ b/include/linux/cyttsp.h
> 
> You may want to move this to include/linux/input/cyttsp.h

Will do.


Thank you for your review Trilok.

> 
> ---Trilok Soni
> 
> --
> Sent by a consultant of the Qualcomm Innovation Center, Inc.
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
> Forum.

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