Re: [PATCH 3/3] max7359_keypad: implement DT bindings

Evgeniy Dushistov
2015-05-17T16:55:25Z

On Fri, May 15, 2015 at 11:00:02PM +0200, Dmitry Torokhov wrote:
> On Thu, May 14, 2015 at 05:38:03AM +0300, Evgeniy Dushistov wrote:
> > + maxim,debounce_reg = /bits/ 8 <0x5F>;
> > + maxim,ports_reg = /bits/ 8 <0xFF>;
>
> Specifying exact size for properties is quite uncommon; I think the
> usual recommendation is is to use the "standard" u32 and validate the
> range in parser function.
>

Using of u8 has advantages, it is possible on compilation stage
(dts->dtb) check that you enter right value, but
because of DT validation tools are not part of mainline,
I replace u8 with u32 as you suggest, see patch bellow.

> > + MATRIX_KEY(0, 7, KEY_RESERVED)
> > + ...
>
>
> Indent one more level? Also, maybe fill with something other than
> KEY_RESERVED?
>

Fixed, see patch bellow.

>
>

> > dev_dbg(&client->dev, "keys FIFO is 0x%02x\n", ret);
> > + if (!keymap_data) {
> > + error = max7359_parse_dt(&client->dev, &init_state);
> > + if (error) {
> > + dev_err(&client->dev, "platform data null, and no DT data\n");
> > + return error;
>
> Both debounce and ports values are optional and we'll fail building
> keymap if there are no platform data nor device tree data, so I would
> drop this check and the stub for max7359_parse_dt() as well - we have
> stubs for property parsing anyway.
>

Because of u32/u8 check at now max7359_parse_dt can return not 0.

> --
> Dmitry
>

Thanks, for review.

Please add me to CC, because of I'm not the part
of any mailing list (too huge traffic for me).
Here patch with fixes mentioned above:

max7359_keypad: implement DT bindings

Signed-off-by: Evgeniy A. Dushistov <dushistov@mail.ru>
---
.../devicetree/bindings/input/max7359-keypad.txt | 33 ++++++++++
drivers/input/keyboard/max7359_keypad.c | 70 +++++++++++++++++++++-
2 files changed, 100 insertions(+), 3 deletions(-)
create mode 100644 Documentation/devicetree/bindings/input/max7359-keypad.txt

diff --git a/Documentation/devicetree/bindings/input/max7359-keypad.txt b/Documentation/devicetree/bindings/input/max7359-keypad.txt
new file mode 100644
index 0000000..5bd4a4f
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/max7359-keypad.txt
@@ -0,0 +1,33 @@
+* MAX7359 keypda device tree bindings
+
+Required Properties:
+- compatible: Should be "maxim,max7359"
+- linux,keymap: The definition can be found at
+ bindings/input/matrix-keymap.txt
+
+Optional Properties:
+- maxim,debounce_reg: u32, in short allow control debounce,
+see max7359 datasheet for details
+- maxim,ports_reg: u32, in short allow control what pin used,
+and what pins should be configured as GPIO
+
+Example:
+max7359_keypad@38 {
+ compatible = "maxim,max7359";
+ reg = <0x38>;
+ interrupts = <28 IRQ_TYPE_LEVEL_LOW>;/*gpio_156*/
+ interrupt-parent = <&gpio5>;
+ maxim,debounce_reg = <0x5F>;
+ maxim,ports_reg = <0xFF>;
+ linux,keymap = <
+ MATRIX_KEY(0, 0, KEY_F1)
+ MATRIX_KEY(0, 1, KEY_RESERVED)
+ MATRIX_KEY(0, 2, KEY_F2)
+ MATRIX_KEY(0, 3, KEY_RESERVED)
+ MATRIX_KEY(0, 4, KEY_M)
+ MATRIX_KEY(0, 5, KEY_L)
+ MATRIX_KEY(0, 6, KEY_P)
+ MATRIX_KEY(0, 7, KEY_ESC)
+ ...
+ >;
+};
diff --git a/drivers/input/keyboard/max7359_keypad.c b/drivers/input/keyboard/max7359_keypad.c
index 5091133..60b4d29 100644
--- a/drivers/input/keyboard/max7359_keypad.c
+++ b/drivers/input/keyboard/max7359_keypad.c
@@ -20,6 +20,7 @@
#include <linux/pm.h>
#include <linux/input.h>
#include <linux/input/matrix_keypad.h>
+#include <linux/of.h>

#define MAX7359_MAX_KEY_ROWS 8
#define MAX7359_MAX_KEY_COLS 8
@@ -64,6 +65,11 @@ struct max7359_keypad {
struct i2c_client *client;
};

+struct max7359_initial_state {
+ u8 debounce_val;
+ u8 ports_val;
+};
+
static int max7359_write_reg(struct i2c_client *client, u8 reg, u8 val)
{
int ret = i2c_smbus_write_byte_data(client, reg, val);
@@ -143,24 +149,64 @@ static void max7359_close(struct input_dev *dev)
max7359_fall_deepsleep(keypad->client);
}

-static void max7359_initialize(struct i2c_client *client)
+static void max7359_initialize(struct i2c_client *client,
+ const struct max7359_initial_state *init_state)
{
max7359_write_reg(client, MAX7359_REG_CONFIG,
MAX7359_CFG_KEY_RELEASE | /* Key release enable */
MAX7359_CFG_WAKEUP); /* Key press wakeup enable */

/* Full key-scan functionality */
- max7359_write_reg(client, MAX7359_REG_DEBOUNCE, 0x1F);
+ max7359_write_reg(client, MAX7359_REG_DEBOUNCE,
+ init_state->debounce_val);

/* nINT asserts every debounce cycles */
max7359_write_reg(client, MAX7359_REG_INTERRUPT, 0x01);
+ max7359_write_reg(client, MAX7359_REG_PORTS, init_state->ports_val);

max7359_fall_deepsleep(client);
}

+#ifdef CONFIG_OF
+static int max7359_parse_dt(struct device *dev,
+ struct max7359_initial_state *init_state)
+{
+ struct device_node *np = dev->of_node;
+ u32 prop;
+
+ if (!of_property_read_u32(np, "maxim,debounce_reg", &prop)) {
+ if (prop > 0xFF) {
+ dev_err(dev, "expect 8bit value for maxim,debounce_reg\n");
+ return -EINVAL;
+ }
+ init_state->debounce_val = prop;
+ }
+
+ if (!of_property_read_u32(np, "maxim,ports_reg", &prop)) {
+ if (prop > 0xFF) {
+ dev_err(dev, "expect 8bit value for maxim,ports_reg\n");
+ return -EINVAL;
+ }
+ init_state->ports_val = prop;
+ }
+
+ return 0;
+}
+#else
+static inline int max7359_parse_dt(struct device *dev,
+ struct max7359_initial_state *init_state)
+{
+ return -EINVAL;
+}
+#endif
+
static int max7359_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
+ struct max7359_initial_state init_state = {
+ .debounce_val = 0x1F,
+ .ports_val = 0xFE,
+ };
const struct matrix_keymap_data *keymap_data =
dev_get_platdata(&client->dev);
struct max7359_keypad *keypad;
@@ -181,6 +227,15 @@ static int max7359_probe(struct i2c_client *client,
}

dev_dbg(&client->dev, "keys FIFO is 0x%02x\n", ret);
+ if (!keymap_data) {
+ error = max7359_parse_dt(&client->dev, &init_state);
+ if (error) {
+ dev_err(&client->dev, "Invalid DT data\n");
+ return error;
+ }
+ dev_dbg(&client->dev, "Init vals: debounce %X, ports %X\n",
+ init_state.debounce_val, init_state.ports_val);
+ }

keypad = devm_kzalloc(&client->dev, sizeof(struct max7359_keypad),
GFP_KERNEL);
@@ -239,7 +294,7 @@ static int max7359_probe(struct i2c_client *client,
}

/* Initialize MAX7359 */
- max7359_initialize(client);
+ max7359_initialize(client, &init_state);

i2c_set_clientdata(client, keypad);
device_init_wakeup(&client->dev, 1);
@@ -282,10 +337,19 @@ static const struct i2c_device_id max7359_ids[] = {
};
MODULE_DEVICE_TABLE(i2c, max7359_ids);

+#ifdef CONFIG_OF
+static const struct of_device_id max7359_dt_match[] = {
+ { .compatible = "maxim,max7359" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, max7359_dt_match);
+#endif
+
static struct i2c_driver max7359_i2c_driver = {
.driver = {
.name = "max7359",
.pm = &max7359_pm,
+ .of_match_table = of_match_ptr(max7359_dt_match),
},
.probe = max7359_probe,
.id_table = max7359_ids,
--
2.3.6

--
/Evgeniy