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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
mfd: lp87565: Handle optional reset pin
Optionally handle the NRST pin (active low reset) in order to start from a
known state during boot and to shut down the chip when rebooting.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
authored by
Luca Ceresoli
and committed by
Lee Jones
50e4d7a2
4700ef32
+28
+27
drivers/mfd/lp87565.c
+27
drivers/mfd/lp87565.c
···
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* Author: Keerthy <j-keerthy@ti.com>
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*/
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#include <linux/gpio/consumer.h>
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#include <linux/interrupt.h>
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#include <linux/mfd/core.h>
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#include <linux/module.h>
···
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return ret;
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}
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lp87565->reset_gpio = devm_gpiod_get_optional(lp87565->dev, "reset",
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GPIOD_OUT_LOW);
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if (IS_ERR(lp87565->reset_gpio)) {
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ret = PTR_ERR(lp87565->reset_gpio);
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if (ret == -EPROBE_DEFER)
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return ret;
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}
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if (lp87565->reset_gpio) {
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gpiod_set_value_cansleep(lp87565->reset_gpio, 1);
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/* The minimum assertion time is undocumented, just guess */
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usleep_range(2000, 4000);
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gpiod_set_value_cansleep(lp87565->reset_gpio, 0);
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/* Min 1.2 ms before first I2C transaction */
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usleep_range(1500, 3000);
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}
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ret = regmap_read(lp87565->regmap, LP87565_REG_OTP_REV, &otpid);
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if (ret) {
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dev_err(lp87565->dev, "Failed to read OTP ID\n");
···
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NULL, 0, NULL);
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}
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static void lp87565_shutdown(struct i2c_client *client)
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{
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struct lp87565 *lp87565 = i2c_get_clientdata(client);
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gpiod_set_value_cansleep(lp87565->reset_gpio, 1);
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}
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static const struct i2c_device_id lp87565_id_table[] = {
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{ "lp87565-q1", 0 },
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{ },
···
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.of_match_table = of_lp87565_match_table,
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},
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.probe = lp87565_probe,
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.shutdown = lp87565_shutdown,
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.id_table = lp87565_id_table,
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};
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module_i2c_driver(lp87565_driver);