Re: [PATCH v2] eeprom/at24: use device_property_*() functions instead of of_get_property()

From: Andy Shevchenko
Date: Thu Feb 09 2017 - 11:20:37 EST


On Thu, Feb 9, 2017 at 5:33 PM, Ben Gardner <gardner.ben@xxxxxxxxx> wrote:
> Allow the at24 driver to get configuration information from both OF and
> ACPI by using the more generic device_property functions.
> This change was inspired by the at25.c driver.
>
> I have a custom board with a ST M24C02 EEPROM attached to an I2C bus.
> With the following ACPI construct, this patch instantiates a working
> instance of the driver.
>
> Device (EEP0) {
> Name (_HID, "PRP0001")
> Name (_DSD, Package () {
> ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
> Package () {
> Package () {"compatible", Package () {"st,24c02"}},
> Package () {"size", 256},
> Package () {"pagesize", 16},
> },
> })
> Name (_CRS, ResourceTemplate () {
> I2cSerialBus (
> 0x0057, ControllerInitiated, 400000,
> AddressingMode7Bit, "\\_SB.PCI0.I2C3", 0x00,
> ResourceConsumer,,)
> })
> }
>
> Note: Matching the driver to the I2C device requires another patch.
> http://www.spinics.net/lists/linux-acpi/msg71914.html
>

Still couple of comments.

> @@ -19,7 +19,6 @@
> #include <linux/log2.h>
> #include <linux/bitops.h>
> #include <linux/jiffies.h>

> -#include <linux/of.h>

I suppose
+ #include <linux/property.h>
?

> +static void at24_get_pdata(struct device *dev,
> + struct at24_platform_data *chip)

Now it fits one line.

> + u32 val;
> +
> + if (device_property_present(dev, "read-only"))
> + chip->flags |= AT24_FLAG_READONLY;
> +
> + if (device_property_read_u32(dev, "pagesize", &val) == 0) {

' == 0' looks awkward.

And I think

ret = x();
if (ret)
...
else
...

pattern would look slightly better.

> + chip->page_size = val;
> + } else {
> + /*
> + * This is slow, but we can't know all eeproms, so we better
> + * play safe. Specifying custom eeprom-types via platform_data
> + * is recommended anyhow.
> + */
> + chip.page_size = 1;

--
With Best Regards,
Andy Shevchenko