Em Sat, 16 Dec 2017 03:49:10 +0100
Philipp Rossak <embed3d@xxxxxxxxx> escreveu:
Hi Phillip,
This is not a full review of this patchset. I just want to point you
that you should keep supporting existing DT files.
> This patch updates the sunxi-ir driver to set the ir base clock from
> devicetree.
>
> This is neccessary since there are different ir recievers on the
> market, that operate with different frequencys. So this value needs to
> be set depending on the attached receiver.
Please don't break backward compatibility with old DT files. In this
specific case, it seems simple enough to be backward-compatible.
>
> Signed-off-by: Philipp Rossak <embed3d@xxxxxxxxx>
> ---
> drivers/media/rc/sunxi-cir.c | 20 +++++++++++---------
> 1 file changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/media/rc/sunxi-cir.c b/drivers/media/rc/sunxi-cir.c
> index 97f367b446c4..55b53d6463e9 100644
> --- a/drivers/media/rc/sunxi-cir.c
> +++ b/drivers/media/rc/sunxi-cir.c
> @@ -72,12 +72,6 @@
> /* CIR_REG register idle threshold */
> #define REG_CIR_ITHR(val) (((val) << 8) & (GENMASK(15, 8)))
>
> -/* Required frequency for IR0 or IR1 clock in CIR mode */
> -#define SUNXI_IR_BASE_CLK 8000000
> -/* Frequency after IR internal divider */
> -#define SUNXI_IR_CLK (SUNXI_IR_BASE_CLK / 64)
Keep those to definitions...
> -/* Sample period in ns */
> -#define SUNXI_IR_SAMPLE (1000000000ul / SUNXI_IR_CLK)
> /* Noise threshold in samples */
> #define SUNXI_IR_RXNOISE 1
> /* Idle Threshold in samples */
> @@ -122,7 +116,7 @@ static irqreturn_t sunxi_ir_irq(int irqno, void *dev_id)
> /* for each bit in fifo */
> dt = readb(ir->base + SUNXI_IR_RXFIFO_REG);
> rawir.pulse = (dt & 0x80) != 0;
> - rawir.duration = ((dt & 0x7f) + 1) * SUNXI_IR_SAMPLE;
> + rawir.duration = ((dt & 0x7f) + 1) * ir->rc->rx_resolution;
> ir_raw_event_store_with_filter(ir->rc, &rawir);
> }
> }
> @@ -148,6 +142,7 @@ static int sunxi_ir_probe(struct platform_device *pdev)
> struct device_node *dn = dev->of_node;
> struct resource *res;
> struct sunxi_ir *ir;
> + u32 b_clk_freq;
>
> ir = devm_kzalloc(dev, sizeof(struct sunxi_ir), GFP_KERNEL);
> if (!ir)
> @@ -172,6 +167,12 @@ static int sunxi_ir_probe(struct platform_device *pdev)
> return PTR_ERR(ir->clk);
> }
>
> + /* Required frequency for IR0 or IR1 clock in CIR mode */
> + if (of_property_read_u32(dn, "base-clk-frequency", &b_clk_freq)) {
> + dev_err(dev, "failed to get ir base clock frequency.\n");
> + return -ENODATA;
> + }
> +
And here, instead of returning an error, if the property can't be read,
it means it is an older DT file. Just default to SUNXI_IR_BASE_CLK.
This will make it backward-compatible with old DT files that don't have
such property.
Regards,
Mauro
> /* Reset (optional) */
> ir->rst = devm_reset_control_get_optional_exclusive(dev, NULL);
> if (IS_ERR(ir->rst))
> @@ -180,7 +181,7 @@ static int sunxi_ir_probe(struct platform_device *pdev)
> if (ret)
> return ret;
>
> - ret = clk_set_rate(ir->clk, SUNXI_IR_BASE_CLK);
> + ret = clk_set_rate(ir->clk, b_clk_freq);
> if (ret) {
> dev_err(dev, "set ir base clock failed!\n");
> goto exit_reset_assert;
> @@ -225,7 +226,8 @@ static int sunxi_ir_probe(struct platform_device *pdev)
> ir->rc->map_name = ir->map_name ?: RC_MAP_EMPTY;
> ir->rc->dev.parent = dev;
> ir->rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
> - ir->rc->rx_resolution = SUNXI_IR_SAMPLE;
> + /* Frequency after IR internal divider with sample period in ns */
> + ir->rc->rx_resolution = (1000000000ul / (b_clk_freq / 64));
> ir->rc->timeout = MS_TO_NS(SUNXI_IR_TIMEOUT);
> ir->rc->driver_name = SUNXI_IR_DEV;
>
Thanks,
Mauro
