On Wed, Aug 17, 2016 at 03:06:39PM -0400, Olimpiu Dejeu wrote:
> This is the driver for the Arctic Sand Technologies Inc. ARCXCNN LED
> backlight IC family.
>
> Signed-off-by: Olimpiu Dejeu <olimpiu@xxxxxxxxxxxxxx>
> ---
> drivers/video/backlight/Kconfig | 7 +
> drivers/video/backlight/Makefile | 1 +
> drivers/video/backlight/arcxcnn_bl.c | 499 +++++++++++++++++++++++++++++++++++
> include/linux/i2c/arcxcnn.h | 41 +++
> 4 files changed, 547 insertions(+)
> create mode 100644 drivers/video/backlight/arcxcnn_bl.c
> create mode 100644 include/linux/i2c/arcxcnn.h
This is a one-patch series with no binding, yet the code below adds a new
compatible string ("arc,arcxcnn"), and DT parsing code assuming
uncommon, non-trivial properties.
You must write a device tree binding document for this.
Please see Documentation/devicetree/bindings/submitting-patches.txt.
> +static int arcxcnn_parse_dt(struct arcxcnn *lp)
> +{
> + struct device *dev = lp->dev;
> + struct device_node *node = dev->of_node;
> + u32 prog_length;
> +
> + if (!node) {
> + dev_err(dev, "no platform data\n");
> + return -EINVAL;
> + }
> +
> + of_property_read_string(node, "bl-name", &lp->pdata->name);
> + of_property_read_u16(node, "init-brt", &lp->pdata->initial_brightness);
> + of_property_read_u32(node, "pwm-period", &lp->pdata->period_ns);
> +
> + if (lp->pdata->initial_brightness > MAX_BRIGHTNESS)
> + lp->pdata->initial_brightness = MAX_BRIGHTNESS;
> +
> + /* Fill program from platform data if defined
> + */
> + lp->pdata->prog_entries = 0;
> + prog_length = of_get_child_count(node);
> + if (prog_length > 0) {
> + struct device_node *child;
> + u32 i = 0;
> +
> + for_each_child_of_node(node, child) {
> + if (i >= ARCXCNN_MAX_PROGENTRIES)
> + break;
> + of_property_read_u8(child, "prg-addr", &lp->pdata->prog_addr[i]);
> + of_property_read_u8(child, "prg-data", &lp->pdata->prog_data[i]);
Don't bother using u8. The DTB is padded to u32 boundaries anyway, so this
just adds an additional burden on DT authors to use /bits/ 8
consistently, which inevitably someone will get wrong.
> +static int arcxcnn_probe(struct i2c_client *cl, const struct i2c_device_id *id)
> +{
> + struct arcxcnn *lp;
> + int ret;
> + u32 i;
> + u8 regval;
> + u16 chipid;
> +
> + if (!i2c_check_functionality(cl->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
> + return -EIO;
> +
> + lp = devm_kzalloc(&cl->dev, sizeof(struct arcxcnn), GFP_KERNEL);
Nit: sizeof(*lp) is the preferred style.
> +static const struct of_device_id arcxcnn_dt_ids[] = {
> + { .compatible = "arc,arcxcnn", },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, arcxcnn_dt_ids);
Thanks,
Mark.
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