2011/8/9 Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>:
> On Mon, Aug 08, 2011 at 11:51:00PM -0700, Dmitry Torokhov wrote:
>
>> The issue I have with the ads7846 driver is that it still needs platform
>> code to supply the needed platform data structure to make the
>> driver/device usable. So I am not sure what the benefit DT matching code
>> brings to that driver.
>
> Oh, if that's the case the driver ought to have device tree bindings
> which replicate the platform data. Unless the platform data is
> sufficiently obscure for hardly anyone to want to use it I guess.
>
With the device tree binding in ads7846, we don't need spi_board_info
any more since we have
ts@0 {
compatible = "ti,ads7845";
reg = <0x0>;
spi-max-frequency = <31250>;
interrupts = <90>;
};
in dts.
I guess what Dmitry said is the big ads7846_platform_data structure.
struct ads7846_platform_data {
u16 model; /* 7843, 7845, 7846, 7873. */
u16 vref_delay_usecs; /* 0 for external vref; etc */
u16 vref_mv; /* external vref value, milliVolts
* ads7846: if 0, use internal vref */
bool keep_vref_on; /* set to keep vref on for differential
* measurements as well */
bool swap_xy; /* swap x and y axes */
/* Settling time of the analog signals; a function of Vcc and the
* capacitance on the X/Y drivers. If set to non-zero, two samples
* are taken with settle_delay us apart, and the second one is used.
* ~150 uSec with 0.01uF caps.
*/
u16 settle_delay_usecs;
/* If set to non-zero, after samples are taken this delay is applied
* and penirq is rechecked, to help avoid false events. This value
* is affected by the material used to build the touch layer.
*/
u16 penirq_recheck_delay_usecs;
u16 x_plate_ohms;
u16 y_plate_ohms;
u16 x_min, x_max;
u16 y_min, y_max;
u16 pressure_min, pressure_max;
u16 debounce_max; /* max number of additional readings
* per sample */
u16 debounce_tol; /* tolerance used for filtering */
u16 debounce_rep; /* additional consecutive good readings
* required after the first two */
int gpio_pendown; /* the GPIO used to decide the pendown
* state if get_pendown_state == NULL
*/
int (*get_pendown_state)(void);
int (*filter_init) (const struct ads7846_platform_data *pdata,
void **filter_data);
int (*filter) (void *filter_data, int data_idx, int *val);
void (*filter_cleanup)(void *filter_data);
void (*wait_for_sync)(void);
bool wakeup;
unsigned long irq_flags;
};
The structure even has some callbacks which can't be possible in dts.
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