[2/3] lirc_zilog: z8 on usb doesn't like back-to-back i2c_master_send
Commit Message
Both the HD-PVR and HVR-1950, driven by the hdpvr and pvrusb2 drivers
respectively, have a zilog z8 chip exposed via i2c. These are both
usb-connected devices, and on both of them, back-to-back i2c_master_send
calls that work fine with a z8 on a pci card fail with a -EIO, as the
chip isn't yet ready from the prior command. To cope with that, add a
delay and retry loop where necessary.
Signed-off-by: Jarod Wilson <jarod@redhat.com>
---
drivers/staging/lirc/lirc_zilog.c | 32 ++++++++++++++++++++++++++------
1 files changed, 26 insertions(+), 6 deletions(-)
Comments
On Thu, 2011-01-20 at 23:30 -0500, Jarod Wilson wrote:
> Both the HD-PVR and HVR-1950, driven by the hdpvr and pvrusb2 drivers
> respectively, have a zilog z8 chip exposed via i2c. These are both
> usb-connected devices, and on both of them, back-to-back i2c_master_send
> calls that work fine with a z8 on a pci card fail with a -EIO, as the
> chip isn't yet ready from the prior command. To cope with that, add a
> delay and retry loop where necessary.
>
> Signed-off-by: Jarod Wilson <jarod@redhat.com>
I haven't tested it, but it looks good.
Acked-by: Andy Walls <awalls@md.metrocast.net>
> ---
> drivers/staging/lirc/lirc_zilog.c | 32 ++++++++++++++++++++++++++------
> 1 files changed, 26 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/staging/lirc/lirc_zilog.c b/drivers/staging/lirc/lirc_zilog.c
> index 3fe5f41..0aad0d7 100644
> --- a/drivers/staging/lirc/lirc_zilog.c
> +++ b/drivers/staging/lirc/lirc_zilog.c
> @@ -495,7 +495,7 @@ static int send_data_block(struct IR_tx *tx, unsigned char *data_block)
> /* send boot data to the IR TX device */
> static int send_boot_data(struct IR_tx *tx)
> {
> - int ret;
> + int ret, i;
> unsigned char buf[4];
>
> /* send the boot block */
> @@ -503,7 +503,7 @@ static int send_boot_data(struct IR_tx *tx)
> if (ret != 0)
> return ret;
>
> - /* kick it off? */
> + /* Hit the go button to activate the new boot data */
> buf[0] = 0x00;
> buf[1] = 0x20;
> ret = i2c_master_send(tx->c, buf, 2);
> @@ -511,7 +511,19 @@ static int send_boot_data(struct IR_tx *tx)
> zilog_error("i2c_master_send failed with %d\n", ret);
> return ret < 0 ? ret : -EFAULT;
> }
> - ret = i2c_master_send(tx->c, buf, 1);
> +
> + /*
> + * Wait for zilog to settle after hitting go post boot block upload.
> + * Without this delay, the HD-PVR and HVR-1950 both return an -EIO
> + * upon attempting to get firmware revision, and tx probe thus fails.
> + */
> + for (i = 0; i < 10; i++) {
> + ret = i2c_master_send(tx->c, buf, 1);
> + if (ret == 1)
> + break;
> + udelay(100);
> + }
> +
> if (ret != 1) {
> zilog_error("i2c_master_send failed with %d\n", ret);
> return ret < 0 ? ret : -EFAULT;
> @@ -523,8 +535,8 @@ static int send_boot_data(struct IR_tx *tx)
> zilog_error("i2c_master_recv failed with %d\n", ret);
> return 0;
> }
> - if (buf[0] != 0x80) {
> - zilog_error("unexpected IR TX response: %02x\n", buf[0]);
> + if ((buf[0] != 0x80) && (buf[0] != 0xa0)) {
> + zilog_error("unexpected IR TX init response: %02x\n", buf[0]);
> return 0;
> }
> zilog_notify("Zilog/Hauppauge IR blaster firmware version "
> @@ -827,7 +839,15 @@ static int send_code(struct IR_tx *tx, unsigned int code, unsigned int key)
> zilog_error("i2c_master_send failed with %d\n", ret);
> return ret < 0 ? ret : -EFAULT;
> }
> - ret = i2c_master_send(tx->c, buf, 1);
> +
> + /* Give the z8 a moment to process data block */
> + for (i = 0; i < 10; i++) {
> + ret = i2c_master_send(tx->c, buf, 1);
> + if (ret == 1)
> + break;
> + udelay(100);
> + }
> +
> if (ret != 1) {
> zilog_error("i2c_master_send failed with %d\n", ret);
> return ret < 0 ? ret : -EFAULT;
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@@ -495,7 +495,7 @@ static int send_data_block(struct IR_tx *tx, unsigned char *data_block)
/* send boot data to the IR TX device */
static int send_boot_data(struct IR_tx *tx)
{
- int ret;
+ int ret, i;
unsigned char buf[4];
/* send the boot block */
@@ -503,7 +503,7 @@ static int send_boot_data(struct IR_tx *tx)
if (ret != 0)
return ret;
- /* kick it off? */
+ /* Hit the go button to activate the new boot data */
buf[0] = 0x00;
buf[1] = 0x20;
ret = i2c_master_send(tx->c, buf, 2);
@@ -511,7 +511,19 @@ static int send_boot_data(struct IR_tx *tx)
zilog_error("i2c_master_send failed with %d\n", ret);
return ret < 0 ? ret : -EFAULT;
}
- ret = i2c_master_send(tx->c, buf, 1);
+
+ /*
+ * Wait for zilog to settle after hitting go post boot block upload.
+ * Without this delay, the HD-PVR and HVR-1950 both return an -EIO
+ * upon attempting to get firmware revision, and tx probe thus fails.
+ */
+ for (i = 0; i < 10; i++) {
+ ret = i2c_master_send(tx->c, buf, 1);
+ if (ret == 1)
+ break;
+ udelay(100);
+ }
+
if (ret != 1) {
zilog_error("i2c_master_send failed with %d\n", ret);
return ret < 0 ? ret : -EFAULT;
@@ -523,8 +535,8 @@ static int send_boot_data(struct IR_tx *tx)
zilog_error("i2c_master_recv failed with %d\n", ret);
return 0;
}
- if (buf[0] != 0x80) {
- zilog_error("unexpected IR TX response: %02x\n", buf[0]);
+ if ((buf[0] != 0x80) && (buf[0] != 0xa0)) {
+ zilog_error("unexpected IR TX init response: %02x\n", buf[0]);
return 0;
}
zilog_notify("Zilog/Hauppauge IR blaster firmware version "
@@ -827,7 +839,15 @@ static int send_code(struct IR_tx *tx, unsigned int code, unsigned int key)
zilog_error("i2c_master_send failed with %d\n", ret);
return ret < 0 ? ret : -EFAULT;
}
- ret = i2c_master_send(tx->c, buf, 1);
+
+ /* Give the z8 a moment to process data block */
+ for (i = 0; i < 10; i++) {
+ ret = i2c_master_send(tx->c, buf, 1);
+ if (ret == 1)
+ break;
+ udelay(100);
+ }
+
if (ret != 1) {
zilog_error("i2c_master_send failed with %d\n", ret);
return ret < 0 ? ret : -EFAULT;