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Subject[RFC/RFT PATCH 1/3] Input: ad7879 - convert to use regmap
Date
Instead of rolling our own infrastructure to provide uniform access to I2C
and SPI buses, let's switch to using regmap.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---

Michael,

I am a bit (actually a lot) confused how this driver was working with SPI
and Blackfin, which is, as far as I understand, little-endian, because from
my reading of the spec the data on wire is big-endian. If this is not
correct we need to change spi regmap config to be:

static const struct regmap_config ad7879_spi_regmap_config = {
.reg_bits = 16,
.val_bits = 16,
.max_register = 15,
.read_flag_mask = AD7879_CMD_MAGIC | AD7879_CMD_READ,
.write_flag_mask = AD7879_CMD_MAGIC,
.reg_format_endian_default = REGMAP_ENDIAN_LITTLE,
.val_format_endian_default = REGMAP_ENDIAN_LITTLE,
};

Also, the original ad7879_spi_xfer was funky to tell the least. We
allocated n+2 spi_transfer structures, then smashed the beginning of the
first one with u16 command, then basically "restored" it???

Anyway, if you could try it out (and fix ;) ), that would be great.

Thanks.

drivers/input/touchscreen/ad7879-i2c.c | 50 ++++-----------
drivers/input/touchscreen/ad7879-spi.c | 112 ++++++---------------------------
drivers/input/touchscreen/ad7879.c | 46 +++++++++-----
drivers/input/touchscreen/ad7879.h | 12 +---
4 files changed, 63 insertions(+), 157 deletions(-)

diff --git a/drivers/input/touchscreen/ad7879-i2c.c b/drivers/input/touchscreen/ad7879-i2c.c
index 58f72e0246ab..25aa9b89a6aa 100644
--- a/drivers/input/touchscreen/ad7879-i2c.c
+++ b/drivers/input/touchscreen/ad7879-i2c.c
@@ -12,53 +12,23 @@
#include <linux/types.h>
#include <linux/of.h>
#include <linux/pm.h>
+#include <linux/regmap.h>

#include "ad7879.h"

#define AD7879_DEVID 0x79 /* AD7879-1/AD7889-1 */

-/* All registers are word-sized.
- * AD7879 uses a high-byte first convention.
- */
-static int ad7879_i2c_read(struct device *dev, u8 reg)
-{
- struct i2c_client *client = to_i2c_client(dev);
-
- return i2c_smbus_read_word_swapped(client, reg);
-}
-
-static int ad7879_i2c_multi_read(struct device *dev,
- u8 first_reg, u8 count, u16 *buf)
-{
- struct i2c_client *client = to_i2c_client(dev);
- u8 idx;
-
- i2c_smbus_read_i2c_block_data(client, first_reg, count * 2, (u8 *)buf);
-
- for (idx = 0; idx < count; ++idx)
- buf[idx] = swab16(buf[idx]);
-
- return 0;
-}
-
-static int ad7879_i2c_write(struct device *dev, u8 reg, u16 val)
-{
- struct i2c_client *client = to_i2c_client(dev);
-
- return i2c_smbus_write_word_swapped(client, reg, val);
-}
-
-static const struct ad7879_bus_ops ad7879_i2c_bus_ops = {
- .bustype = BUS_I2C,
- .read = ad7879_i2c_read,
- .multi_read = ad7879_i2c_multi_read,
- .write = ad7879_i2c_write,
+static const struct regmap_config ad7879_i2c_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 16,
+ .max_register = 15,
};

static int ad7879_i2c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct ad7879 *ts;
+ struct regmap *regmap;

if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_WORD_DATA)) {
@@ -66,8 +36,12 @@ static int ad7879_i2c_probe(struct i2c_client *client,
return -EIO;
}

- ts = ad7879_probe(&client->dev, AD7879_DEVID, client->irq,
- &ad7879_i2c_bus_ops);
+ regmap = devm_regmap_init_i2c(client, &ad7879_i2c_regmap_config);
+ if (IS_ERR(regmap))
+ return PTR_ERR(regmap);
+
+ ts = ad7879_probe(&client->dev, regmap, client->irq,
+ BUS_I2C, AD7879_DEVID);
if (IS_ERR(ts))
return PTR_ERR(ts);

diff --git a/drivers/input/touchscreen/ad7879-spi.c b/drivers/input/touchscreen/ad7879-spi.c
index d42b6b9af191..e9535aacaabf 100644
--- a/drivers/input/touchscreen/ad7879-spi.c
+++ b/drivers/input/touchscreen/ad7879-spi.c
@@ -11,109 +11,29 @@
#include <linux/spi/spi.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/regmap.h>

#include "ad7879.h"

#define AD7879_DEVID 0x7A /* AD7879/AD7889 */

#define MAX_SPI_FREQ_HZ 5000000
-#define AD7879_CMD_MAGIC 0xE000
-#define AD7879_CMD_READ (1 << 10)
-#define AD7879_CMD(reg) (AD7879_CMD_MAGIC | ((reg) & 0xF))
-#define AD7879_WRITECMD(reg) (AD7879_CMD(reg))
-#define AD7879_READCMD(reg) (AD7879_CMD(reg) | AD7879_CMD_READ)
-
-/*
- * ad7879_read/write are only used for initial setup and for sysfs controls.
- * The main traffic is done in ad7879_collect().
- */
-
-static int ad7879_spi_xfer(struct spi_device *spi,
- u16 cmd, u8 count, u16 *tx_buf, u16 *rx_buf)
-{
- struct spi_message msg;
- struct spi_transfer *xfers;
- void *spi_data;
- u16 *command;
- u16 *_rx_buf = _rx_buf; /* shut gcc up */
- u8 idx;
- int ret;
-
- xfers = spi_data = kzalloc(sizeof(*xfers) * (count + 2), GFP_KERNEL);
- if (!spi_data)
- return -ENOMEM;
-
- spi_message_init(&msg);
-
- command = spi_data;
- command[0] = cmd;
- if (count == 1) {
- /* ad7879_spi_{read,write} gave us buf on stack */
- command[1] = *tx_buf;
- tx_buf = &command[1];
- _rx_buf = rx_buf;
- rx_buf = &command[2];
- }
-
- ++xfers;
- xfers[0].tx_buf = command;
- xfers[0].len = 2;
- spi_message_add_tail(&xfers[0], &msg);
- ++xfers;
-
- for (idx = 0; idx < count; ++idx) {
- if (rx_buf)
- xfers[idx].rx_buf = &rx_buf[idx];
- if (tx_buf)
- xfers[idx].tx_buf = &tx_buf[idx];
- xfers[idx].len = 2;
- spi_message_add_tail(&xfers[idx], &msg);
- }
-
- ret = spi_sync(spi, &msg);
-
- if (count == 1)
- _rx_buf[0] = command[2];
-
- kfree(spi_data);
-
- return ret;
-}

-static int ad7879_spi_multi_read(struct device *dev,
- u8 first_reg, u8 count, u16 *buf)
-{
- struct spi_device *spi = to_spi_device(dev);
-
- return ad7879_spi_xfer(spi, AD7879_READCMD(first_reg), count, NULL, buf);
-}
-
-static int ad7879_spi_read(struct device *dev, u8 reg)
-{
- struct spi_device *spi = to_spi_device(dev);
- u16 ret, dummy;
-
- return ad7879_spi_xfer(spi, AD7879_READCMD(reg), 1, &dummy, &ret) ? : ret;
-}
-
-static int ad7879_spi_write(struct device *dev, u8 reg, u16 val)
-{
- struct spi_device *spi = to_spi_device(dev);
- u16 dummy;
-
- return ad7879_spi_xfer(spi, AD7879_WRITECMD(reg), 1, &val, &dummy);
-}
-
-static const struct ad7879_bus_ops ad7879_spi_bus_ops = {
- .bustype = BUS_SPI,
- .read = ad7879_spi_read,
- .multi_read = ad7879_spi_multi_read,
- .write = ad7879_spi_write,
+#define AD7879_CMD_MAGIC 0xE000
+#define AD7879_CMD_READ BIT(10)
+
+static const struct regmap_config ad7879_spi_regmap_config = {
+ .reg_bits = 16,
+ .val_bits = 16,
+ .max_register = 15,
+ .read_flag_mask = AD7879_CMD_MAGIC | AD7879_CMD_READ,
+ .write_flag_mask = AD7879_CMD_MAGIC,
};

static int ad7879_spi_probe(struct spi_device *spi)
{
struct ad7879 *ts;
+ struct regmap *regmap;
int err;

/* don't exceed max specified SPI CLK frequency */
@@ -125,11 +45,15 @@ static int ad7879_spi_probe(struct spi_device *spi)
spi->bits_per_word = 16;
err = spi_setup(spi);
if (err) {
- dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n");
- return err;
+ dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n");
+ return err;
}

- ts = ad7879_probe(&spi->dev, AD7879_DEVID, spi->irq, &ad7879_spi_bus_ops);
+ regmap = devm_regmap_init_spi(spi, &ad7879_spi_regmap_config);
+ if (IS_ERR(regmap))
+ return PTR_ERR(regmap);
+
+ ts = ad7879_probe(&spi->dev, regmap, spi->irq, BUS_SPI, AD7879_DEVID);
if (IS_ERR(ts))
return PTR_ERR(ts);

diff --git a/drivers/input/touchscreen/ad7879.c b/drivers/input/touchscreen/ad7879.c
index e16a44667da7..6465db7a1b20 100644
--- a/drivers/input/touchscreen/ad7879.c
+++ b/drivers/input/touchscreen/ad7879.c
@@ -26,9 +26,8 @@
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
+#include <linux/regmap.h>
#include <linux/slab.h>
-#include <linux/spi/spi.h>
-#include <linux/i2c.h>
#include <linux/gpio.h>

#include <linux/input/touchscreen.h>
@@ -106,8 +105,7 @@ enum {
#define TS_PEN_UP_TIMEOUT msecs_to_jiffies(50)

struct ad7879 {
- const struct ad7879_bus_ops *bops;
-
+ struct regmap *regmap;
struct device *dev;
struct input_dev *input;
struct timer_list timer;
@@ -137,17 +135,32 @@ struct ad7879 {

static int ad7879_read(struct ad7879 *ts, u8 reg)
{
- return ts->bops->read(ts->dev, reg);
-}
+ unsigned int val;
+ int error;

-static int ad7879_multi_read(struct ad7879 *ts, u8 first_reg, u8 count, u16 *buf)
-{
- return ts->bops->multi_read(ts->dev, first_reg, count, buf);
+ error = regmap_read(ts->regmap, reg, &val);
+ if (error) {
+ dev_err(ts->dev, "failed to read register %#02x: %d\n",
+ reg, error);
+ return error;
+ }
+
+ return val;
}

static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
{
- return ts->bops->write(ts->dev, reg, val);
+ int error;
+
+ error = regmap_write(ts->regmap, reg, val);
+ if (error) {
+ dev_err(ts->dev,
+ "failed to write %#04x to register %#02x: %d\n",
+ val, reg, error);
+ return error;
+ }
+
+ return 0;
}

static int ad7879_report(struct ad7879 *ts)
@@ -234,7 +247,8 @@ static irqreturn_t ad7879_irq(int irq, void *handle)
{
struct ad7879 *ts = handle;

- ad7879_multi_read(ts, AD7879_REG_XPLUS, AD7879_NR_SENSE, ts->conversion_data);
+ regmap_bulk_read(ts->regmap, AD7879_REG_XPLUS,
+ ts->conversion_data, AD7879_NR_SENSE);

if (!ad7879_report(ts))
mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
@@ -511,8 +525,8 @@ static int ad7879_parse_dt(struct device *dev, struct ad7879 *ts)
return 0;
}

-struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
- const struct ad7879_bus_ops *bops)
+struct ad7879 *ad7879_probe(struct device *dev, struct regmap *regmap,
+ int irq, u16 bustype, u8 devid)
{
struct ad7879_platform_data *pdata = dev_get_platdata(dev);
struct ad7879 *ts;
@@ -520,7 +534,7 @@ struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
int err;
u16 revid;

- if (!irq) {
+ if (irq <= 0) {
dev_err(dev, "No IRQ specified\n");
return ERR_PTR(-EINVAL);
}
@@ -553,10 +567,10 @@ struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
return ERR_PTR(-ENOMEM);
}

- ts->bops = bops;
ts->dev = dev;
ts->input = input_dev;
ts->irq = irq;
+ ts->regmap = regmap;

setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
@@ -564,7 +578,7 @@ struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
input_dev->name = "AD7879 Touchscreen";
input_dev->phys = ts->phys;
input_dev->dev.parent = dev;
- input_dev->id.bustype = bops->bustype;
+ input_dev->id.bustype = bustype;

input_dev->open = ad7879_open;
input_dev->close = ad7879_close;
diff --git a/drivers/input/touchscreen/ad7879.h b/drivers/input/touchscreen/ad7879.h
index 6fd13c48d373..1131f8aa118b 100644
--- a/drivers/input/touchscreen/ad7879.h
+++ b/drivers/input/touchscreen/ad7879.h
@@ -13,18 +13,12 @@

struct ad7879;
struct device;
-
-struct ad7879_bus_ops {
- u16 bustype;
- int (*read)(struct device *dev, u8 reg);
- int (*multi_read)(struct device *dev, u8 first_reg, u8 count, u16 *buf);
- int (*write)(struct device *dev, u8 reg, u16 val);
-};
+struct regmap;

extern const struct dev_pm_ops ad7879_pm_ops;

-struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned irq,
- const struct ad7879_bus_ops *bops);
+struct ad7879 *ad7879_probe(struct device *dev, struct regmap *regmap,
+ int irq, u16 bustype, u8 devid);
void ad7879_remove(struct ad7879 *);

#endif
--
2.11.0.483.g087da7b7c-goog
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