On Fri, 22 Nov 2013, Thierry Reding wrote:
> From: Rhyland Klein <[email protected]>
>
> The EC has specific timing it requires. Add support for an optional delay
> after raising CS to fix timing issues. This is configurable based on
> a DT property "google,cros-ec-spi-msg-delay".
>
> If this property isn't set, then no delay will be added. However, if set
> it will cause a delay equal to the value passed to it to be inserted at
> the end of a transaction.
>
> Signed-off-by: Rhyland Klein <[email protected]>
> Reviewed-by: Bernie Thompson <[email protected]>
> Reviewed-by: Andrew Bresticker <[email protected]>
> Cc: Rob Herring <[email protected]>
> Cc: Pawel Moll <[email protected]>
> Cc: Mark Rutland <[email protected]>
> Cc: Ian Campbell <[email protected]>
> Signed-off-by: Thierry Reding <[email protected]>
> ---
> Changes in v2:
> - make property description more verbose
>
> Documentation/devicetree/bindings/mfd/cros-ec.txt | 9 +++++++
We need a DT dude to look over this.
> drivers/mfd/cros_ec_spi.c | 30
> +++++++++++++++++++++++
> 2 files changed, 39 insertions(+)
<snip>
> static void debug_packet(struct device *dev, const char *name, u8 *ptr,
> @@ -238,6 +242,17 @@ static int cros_ec_command_spi_xfer(struct
> cros_ec_device *ec_dev,
>
> /* turn off CS */
> spi_message_init(&msg);
> +
> + if (ec_spi->end_of_msg_delay) {
> + /*
> + * Add delay for last transaction, to ensure the rising edge
> + * doesn't come too soon after the end of the data.
> + */
> + memset(&trans, '\0', sizeof(trans));
Just use the usual 0 for the third parameter.
> +static void cros_ec_probe_spi_dt(struct cros_ec_spi *ec_spi, struct device
> *dev)
Traditionally we have 'probe' as the last word in the function name.
> +{
> + struct device_node *np = dev->of_node;
> + u32 val;
> + int ret;
> +
> + ret = of_property_read_u32(np, "google,cros-ec-spi-msg-delay", &val);
> + if (!ret)
> + ec_spi->end_of_msg_delay = val;
> +}
> +
> static int cros_ec_probe_spi(struct spi_device *spi)
Can you send a pre-patch to fix this too please:
static int cros_ec_spi_probe(struct spi_device *spi)
<snip>
> + /* Check for any DT properties */
> + if (IS_ENABLED(CONFIG_OF) && dev->of_node)
No need for the first check.
> + cros_ec_probe_spi_dt(ec_spi, dev);
> +
> spi_set_drvdata(spi, ec_dev);
> ec_dev->name = "SPI";
> ec_dev->dev = dev;
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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