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SubjectRe: [PATCH v6 3/3] Input: cyttsp - add support for Cypress TTSP touchscreen SPI bus interface
On Tue, Oct 18, 2011 at 10:27 AM, Shubhrajyoti Datta
<omaplinuxkernel@gmail.com> wrote:
>
>
> On Sun, Oct 16, 2011 at 12:07 AM, <martinez.javier@gmail.com> wrote:
>>
>> From: Javier Martinez Canillas <martinez.javier@gmail.com>
>>
>> The driver is composed of a core driver that process the data sent by
>> the contacts and a set of bus specific interface modules.
>>
>> This patch add supports for the Cypress TTSP SPI bus interface.
>>
>> Signed-off-by: Javier Martinez Canillas <martinez.javier@gmail.com>
>> ---
>>
>> v2: Fix issues called out by Dmitry Torokhov
>>     - Extract the IRQ from the spi client data and pass to
>> cyttsp_core_init()
>>     - Remove the extra retries and limit the retries to the cyttsp_core.c
>>       read/write block functions.
>>     - Cleanup cyttsp_spi_xfer(), check ACK in write operation and fix
>> special
>>       EIO case to show its meaning.
>>
>> v3: Fix issues called out by Henrik Rydberg and Mohan Pallaka
>>    - Remove bus type info since it is not used.
>>
>>  drivers/input/touchscreen/cyttsp/cyttsp_spi.c |  295
>> +++++++++++++++++++++++++
>>  1 files changed, 295 insertions(+), 0 deletions(-)
>>  create mode 100644 drivers/input/touchscreen/cyttsp/cyttsp_spi.c
>>
>> diff --git a/drivers/input/touchscreen/cyttsp/cyttsp_spi.c
>> b/drivers/input/touchscreen/cyttsp/cyttsp_spi.c
>> new file mode 100644
>> index 0000000..66d6dc3
>> --- /dev/null
>> +++ b/drivers/input/touchscreen/cyttsp/cyttsp_spi.c
>> @@ -0,0 +1,295 @@
>> +/*
>> + * Source for:
>> + * Cypress TrueTouch(TM) Standard Product (TTSP) SPI touchscreen driver.
>> + * For use with Cypress Txx3xx parts.
>> + * Supported parts include:
>> + * CY8CTST341
>> + * CY8CTMA340
>> + *
>> + * Copyright (C) 2009, 2010, 2011 Cypress Semiconductor, Inc.
>> + * Copyright (C) 2011 Javier Martinez Canillas
>> <martinez.javier@gmail.com>
>> + *
>> + * Multi-touch protocol type B support and cleanups by Javier Martinez
>> Canillas
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License
>> + * version 2, and only version 2, as published by the
>> + * Free Software Foundation.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> along
>> + * with this program; if not, write to the Free Software Foundation,
>> Inc.,
>> + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
>> + *
>> + * Contact Cypress Semiconductor at www.cypress.com <kev@cypress.com>
>> + *
>> + */
>> +
>> +#include "cyttsp_core.h"
>> +
>> +#include <linux/spi/spi.h>
>> +#include <linux/delay.h>
>> +
>> +#define CY_SPI_WR_OP      0x00 /* r/~w */
>> +#define CY_SPI_RD_OP      0x01
>> +#define CY_SPI_CMD_BYTES  4
>> +#define CY_SPI_SYNC_BYTE  2
>> +#define CY_SPI_SYNC_ACK1  0x62 /* from protocol v.2 */
>> +#define CY_SPI_SYNC_ACK2  0x9D /* from protocol v.2 */
>> +#define CY_SPI_DATA_SIZE  128
>> +#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 bus_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 int cyttsp_spi_xfer(u8 op, struct cyttsp_spi *ts,
>> +                          u8 reg, u8 *buf, int length)
>> +{
>> +       struct spi_message msg;
>> +       struct spi_transfer xfer[2];
>> +       u8 *wr_buf = ts->wr_buf;
>> +       u8 *rd_buf = ts->rd_buf;
>> +       int retval;
>> +
>> +       if (length > CY_SPI_DATA_SIZE) {
>> +               dev_dbg(ts->bus_ops.dev,
>> +                       "%s: length %d is too big.\n",
>> +                       __func__, length);
>> +               return -EINVAL;
>> +       }
>> +
>> +       memset(wr_buf, 0, CY_SPI_DATA_BUF_SIZE);
>> +       memset(rd_buf, 0, CY_SPI_DATA_BUF_SIZE);
>> +
>> +       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);
>> +
>> +       memset((void *)xfer, 0, sizeof(xfer));
>> +       spi_message_init(&msg);
>> +
>> +       /*
>> +         We set both TX and RX buffers because Cypress TTSP
>> +         requires full duplex operation.
>> +       */
>> +       xfer[0].tx_buf = wr_buf;
>> +       xfer[0].rx_buf = rd_buf;
>> +       if (op == CY_SPI_WR_OP) {
>> +               xfer[0].len = length + CY_SPI_CMD_BYTES;
>> +               spi_message_add_tail(&xfer[0], &msg);
>> +       } else if (op == CY_SPI_RD_OP) {
>> +               xfer[0].len = CY_SPI_CMD_BYTES;
>> +               spi_message_add_tail(&xfer[0], &msg);
>> +
>> +               xfer[1].rx_buf = buf;
>> +               xfer[1].len = length;
>> +               spi_message_add_tail(&xfer[1], &msg);
>> +       }
>> +
>> +       retval = spi_sync(ts->spi_client, &msg);
>> +       if (retval < 0) {
>> +               dev_dbg(ts->bus_ops.dev,
>> +                       "%s: spi_sync() error %d, len=%d, op=%d\n",
>> +                       __func__, retval, xfer[1].len, op);
>> +
>> +               /*
>> +                * do not return here since was a bad ACK sequence
>> +                * let the following ACK check handle any errors and
>> +                * allow silent retries
>> +                */
>> +       }
>> +
>> +       if ((rd_buf[CY_SPI_SYNC_BYTE] == CY_SPI_SYNC_ACK1) &&
>> +           (rd_buf[CY_SPI_SYNC_BYTE+1] == CY_SPI_SYNC_ACK2))
>> +               retval = 0;
>> +       else {
>> +               int i;
>> +               for (i = 0; i < (CY_SPI_CMD_BYTES); i++)
>> +                       dev_dbg(ts->bus_ops.dev,
>> +                               "%s: test rd_buf[%d]:0x%02x\n",
>> +                               __func__, i, rd_buf[i]);
>> +               for (i = 0; i < (length); i++)
>> +                       dev_dbg(ts->bus_ops.dev,
>> +                               "%s: test buf[%d]:0x%02x\n",
>> +                               __func__, i, buf[i]);
>> +
>> +               /* signal ACK error so silent retry */
>> +               retval = 1;
>> +       }
>> +
>> +       return retval;
>> +}
>> +
>> +static s32 ttsp_spi_read_block_data(void *handle, u8 addr,
>> +                                   u8 length, void *data)
>> +{
>> +       struct cyttsp_spi *ts =
>> +               container_of(handle, struct cyttsp_spi, bus_ops);
>> +       int retval;
>> +
>> +       retval = cyttsp_spi_xfer(CY_SPI_RD_OP, ts, addr, data, length);
>> +       if (retval < 0)
>> +               pr_err("%s: ttsp_spi_read_block_data failed\n",
>> +                      __func__);
>> +
>> +       /*
>> +        * 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.
>> +        */
>> +       if (retval > 0)
>> +               retval = -EIO;  /* 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)
>> +{
>> +       struct cyttsp_spi *ts =
>> +               container_of(handle, struct cyttsp_spi, bus_ops);
>> +       int retval;
>> +
>> +       retval = cyttsp_spi_xfer(CY_SPI_WR_OP, ts, addr, (void *)data,
>> length);
>> +       if (retval < 0)
>> +               pr_err("%s: ttsp_spi_write_block_data failed\n",
>> +                      __func__);
>> +
>> +       /*
>> +        * 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.
>> +        */
>> +       if (retval > 0)
>> +               retval = -EIO;  /* now signal fail; so retry can be done
>> */
>> +
>> +       return retval;
>> +}
>> +
>> +static s32 ttsp_spi_tch_ext(void *handle, void *values)
>> +{
>> +       struct cyttsp_spi *ts =
>> +               container_of(handle, struct cyttsp_spi, bus_ops);
>> +       int retval = 0;
>> +
>> +       /*
>> +        * TODO: Add custom touch extension handling code here
>> +        * 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
>> +        */
>> +
>
> This is an empty function and could be removed?
>
>

Hi Shubhrajyoti,

Yes, I'll remove it and also fix the other issues called out by you
and resend the patch-set as v7.

Thanks a lot for the review and best regards,

--
Javier Martínez Canillas
(+34) 682 39 81 69
Barcelona, Spain
--
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