Em Tue, 15 Oct 2013 17:24:38 +0200
Dinesh Ram <dinesh.ram@xxxxxxx> escreveu:
> Checks have been introduced at several places in the code to test if an interrupt is set or not.
> For devices which do not use the interrupt, to get a valid response, within a specified timeout,
> the device is polled instead.
>
> Signed-off-by: Dinesh Ram <dinesh.ram@xxxxxxx>
> ---
> drivers/media/radio/si4713/si4713.c | 108 +++++++++++++++++++++--------------
> 1 file changed, 64 insertions(+), 44 deletions(-)
>
> diff --git a/drivers/media/radio/si4713/si4713.c b/drivers/media/radio/si4713/si4713.c
> index ac727e3..24ae41d 100644
> --- a/drivers/media/radio/si4713/si4713.c
> +++ b/drivers/media/radio/si4713/si4713.c
> @@ -27,11 +27,11 @@
> #include <linux/i2c.h>
> #include <linux/slab.h>
> #include <linux/gpio.h>
> -#include <linux/regulator/consumer.h>
> #include <linux/module.h>
> #include <media/v4l2-device.h>
> #include <media/v4l2-ioctl.h>
> #include <media/v4l2-common.h>
> +#include <linux/regulator/consumer.h>
>
> #include "si4713.h"
>
> @@ -213,6 +213,7 @@ static int si4713_send_command(struct si4713_device *sdev, const u8 command,
> u8 response[], const int respn, const int usecs)
> {
> struct i2c_client *client = v4l2_get_subdevdata(&sdev->sd);
> + unsigned long until_jiffies;
> u8 data1[MAX_ARGS + 1];
> int err;
>
> @@ -228,30 +229,39 @@ static int si4713_send_command(struct si4713_device *sdev, const u8 command,
> if (err != argn + 1) {
> v4l2_err(&sdev->sd, "Error while sending command 0x%02x\n",
> command);
> - return (err > 0) ? -EIO : err;
> + return err < 0 ? err : -EIO;
> }
>
> + until_jiffies = jiffies + usecs_to_jiffies(usecs) + 1;
> +
> /* Wait response from interrupt */
> - if (!wait_for_completion_timeout(&sdev->work,
> + if (client->irq) {
> + if (!wait_for_completion_timeout(&sdev->work,
> usecs_to_jiffies(usecs) + 1))
> - v4l2_warn(&sdev->sd,
> + v4l2_warn(&sdev->sd,
> "(%s) Device took too much time to answer.\n",
> __func__);
> -
> - /* Then get the response */
> - err = i2c_master_recv(client, response, respn);
> - if (err != respn) {
> - v4l2_err(&sdev->sd,
> - "Error while reading response for command 0x%02x\n",
> - command);
> - return (err > 0) ? -EIO : err;
> }
>
> - DBG_BUFFER(&sdev->sd, "Response", response, respn);
> - if (check_command_failed(response[0]))
> - return -EBUSY;
> + do {
> + err = i2c_master_recv(client, response, respn);
> + if (err != respn) {
> + v4l2_err(&sdev->sd,
> + "Error %d while reading response for command 0x%02x\n",
> + err, command);
> + return err < 0 ? err : -EIO;
> + }
> +
> + DBG_BUFFER(&sdev->sd, "Response", response, respn);
> + if (!check_command_failed(response[0]))
> + return 0;
>
> - return 0;
> + if (client->irq)
> + return -EBUSY;
> + msleep(1);
> + } while (jiffies <= until_jiffies);
This could result on an endless loop due to the limited space for jiffies.
You should, instead, use the proper macros (time_after, time_before, ...).
> +
> + return -EBUSY;
> }
>
> /*
> @@ -344,14 +354,15 @@ static int si4713_write_property(struct si4713_device *sdev, u16 prop, u16 val)
> */
> static int si4713_powerup(struct si4713_device *sdev)
> {
> + struct i2c_client *client = v4l2_get_subdevdata(&sdev->sd);
> int err;
> u8 resp[SI4713_PWUP_NRESP];
> /*
> * .First byte = Enabled interrupts and boot function
> * .Second byte = Input operation mode
> */
> - const u8 args[SI4713_PWUP_NARGS] = {
> - SI4713_PWUP_CTSIEN | SI4713_PWUP_GPO2OEN | SI4713_PWUP_FUNC_TX,
> + u8 args[SI4713_PWUP_NARGS] = {
> + SI4713_PWUP_GPO2OEN | SI4713_PWUP_FUNC_TX,
> SI4713_PWUP_OPMOD_ANALOG,
> };
>
> @@ -369,6 +380,9 @@ static int si4713_powerup(struct si4713_device *sdev)
> gpio_set_value(sdev->gpio_reset, 1);
> }
>
> + if (client->irq)
> + args[0] |= SI4713_PWUP_CTSIEN;
> +
> err = si4713_send_command(sdev, SI4713_CMD_POWER_UP,
> args, ARRAY_SIZE(args),
> resp, ARRAY_SIZE(resp),
> @@ -380,7 +394,8 @@ static int si4713_powerup(struct si4713_device *sdev)
> v4l2_dbg(1, debug, &sdev->sd, "Device in power up mode\n");
> sdev->power_state = POWER_ON;
>
> - err = si4713_write_property(sdev, SI4713_GPO_IEN,
> + if (client->irq)
> + err = si4713_write_property(sdev, SI4713_GPO_IEN,
> SI4713_STC_INT | SI4713_CTS);
> } else {
> if (gpio_is_valid(sdev->gpio_reset))
> @@ -465,33 +480,39 @@ static int si4713_checkrev(struct si4713_device *sdev)
> */
> static int si4713_wait_stc(struct si4713_device *sdev, const int usecs)
> {
> - int err;
> + struct i2c_client *client = v4l2_get_subdevdata(&sdev->sd);
> u8 resp[SI4713_GET_STATUS_NRESP];
> + unsigned long start_jiffies = jiffies;
> + int err;
>
> - /* Wait response from STC interrupt */
> - if (!wait_for_completion_timeout(&sdev->work,
> - usecs_to_jiffies(usecs) + 1))
> + if (client->irq &&
> + !wait_for_completion_timeout(&sdev->work, usecs_to_jiffies(usecs) + 1))
> v4l2_warn(&sdev->sd,
> - "%s: device took too much time to answer (%d usec).\n",
> - __func__, usecs);
> -
> - /* Clear status bits */
> - err = si4713_send_command(sdev, SI4713_CMD_GET_INT_STATUS,
> - NULL, 0,
> - resp, ARRAY_SIZE(resp),
> - DEFAULT_TIMEOUT);
> -
> - if (err < 0)
> - goto exit;
> -
> - v4l2_dbg(1, debug, &sdev->sd,
> - "%s: status bits: 0x%02x\n", __func__, resp[0]);
> -
> - if (!(resp[0] & SI4713_STC_INT))
> - err = -EIO;
> -
> -exit:
> - return err;
> + "(%s) Device took too much time to answer.\n", __func__);
> +
> + for (;;) {
> + /* Clear status bits */
> + err = si4713_send_command(sdev, SI4713_CMD_GET_INT_STATUS,
> + NULL, 0,
> + resp, ARRAY_SIZE(resp),
> + DEFAULT_TIMEOUT);
> + /* The USB device returns errors when it waits for the
> + * STC bit to be set. Hence polling */
> + if (err >= 0) {
> + v4l2_dbg(1, debug, &sdev->sd,
> + "%s: status bits: 0x%02x\n", __func__, resp[0]);
> +
> + if (resp[0] & SI4713_STC_INT)
> + return 0;
> + }
> + if (jiffies_to_usecs(jiffies - start_jiffies) > usecs)
Same here: use the proper macro to check time after/before.
> + return err < 0 ? err : -EIO;
> + /* We sleep here for 3 ms in order to avoid flooding the device
> + * with USB requests. The si4713 USB driver was developed
> + * by reverse engineering the Windows USB driver. The windows
> + * driver also has a ~2.5 ms delay between responses. */
> + msleep(3);
> + }
> }
>
> /*
> @@ -1024,7 +1045,6 @@ static int si4713_initialize(struct si4713_device *sdev)
> if (rval < 0)
> return rval;
>
> -
> sdev->frequency = DEFAULT_FREQUENCY;
> sdev->stereo = 1;
> sdev->tune_rnl = DEFAULT_TUNE_RNL;
--
Cheers,
Mauro
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