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

Kevin McNeely
2010-08-10T00:51:23Z

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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