pwm: add pca9685 driver
Add pwm driver for the NXP pca9685 16 channel pwm-led controller. The driver is really barebones at this stage. E.g. the OE' pin and therefore the corresponding registers are not supported. The driver was tested on a HW where this pin is tied to GND. Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de> [thierry.reding@gmail.com: style and whitespace cleanups] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
This commit is contained in:
Steffen Trumtrar
Thierry Reding
Родитель
8796f9c565
Коммит
88b613e623
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@ -0,0 +1,27 @@
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NXP PCA9685 16-channel 12-bit PWM LED controller
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================================================
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Required properties:
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- compatible: "nxp,pca9685-pwm"
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- #pwm-cells: should be 2. The first cell specifies the per-chip index
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of the PWM to use and the second cell is the period in nanoseconds.
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The index 16 is the ALLCALL channel, that sets all PWM channels at the same
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time.
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Optional properties:
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- invert (bool): boolean to enable inverted logic
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- open-drain (bool): boolean to configure outputs with open-drain structure;
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if omitted use totem-pole structure
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Example:
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For LEDs that are directly connected to the PCA, the following setting is
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applicable:
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pca: pca@41 {
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compatible = "nxp,pca9685-pwm";
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#pwm-cells = <2>;
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reg = <0x41>;
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invert;
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open-drain;
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};
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@ -97,6 +97,15 @@ config PWM_MXS
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To compile this driver as a module, choose M here: the module
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will be called pwm-mxs.
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config PWM_PCA9685
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tristate "NXP PCA9685 PWM driver"
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depends on OF && REGMAP_I2C
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help
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Generic PWM framework driver for NXP PCA9685 LED controller.
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To compile this driver as a module, choose M here: the module
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will be called pwm-pca9685.
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config PWM_PUV3
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tristate "PKUnity NetBook-0916 PWM support"
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depends on ARCH_PUV3
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@ -6,6 +6,7 @@ obj-$(CONFIG_PWM_IMX) += pwm-imx.o
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obj-$(CONFIG_PWM_JZ4740) += pwm-jz4740.o
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obj-$(CONFIG_PWM_LPC32XX) += pwm-lpc32xx.o
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obj-$(CONFIG_PWM_MXS) += pwm-mxs.o
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obj-$(CONFIG_PWM_PCA9685) += pwm-pca9685.o
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obj-$(CONFIG_PWM_PUV3) += pwm-puv3.o
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obj-$(CONFIG_PWM_PXA) += pwm-pxa.o
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obj-$(CONFIG_PWM_SAMSUNG) += pwm-samsung.o
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@ -0,0 +1,298 @@
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/*
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* Driver for PCA9685 16-channel 12-bit PWM LED controller
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*
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* Copyright (C) 2013 Steffen Trumtrar <s.trumtrar@pengutronix.de>
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*
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* based on the pwm-twl-led.c driver
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/i2c.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/pwm.h>
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#include <linux/regmap.h>
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#include <linux/slab.h>
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#define PCA9685_MODE1 0x00
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#define PCA9685_MODE2 0x01
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#define PCA9685_SUBADDR1 0x02
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#define PCA9685_SUBADDR2 0x03
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#define PCA9685_SUBADDR3 0x04
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#define PCA9685_ALLCALLADDR 0x05
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#define PCA9685_LEDX_ON_L 0x06
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#define PCA9685_LEDX_ON_H 0x07
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#define PCA9685_LEDX_OFF_L 0x08
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#define PCA9685_LEDX_OFF_H 0x09
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#define PCA9685_ALL_LED_ON_L 0xFA
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#define PCA9685_ALL_LED_ON_H 0xFB
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#define PCA9685_ALL_LED_OFF_L 0xFC
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#define PCA9685_ALL_LED_OFF_H 0xFD
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#define PCA9685_PRESCALE 0xFE
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#define PCA9685_NUMREGS 0xFF
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#define PCA9685_MAXCHAN 0x10
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#define LED_FULL (1 << 4)
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#define MODE1_SLEEP (1 << 4)
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#define MODE2_INVRT (1 << 4)
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#define MODE2_OUTDRV (1 << 2)
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#define LED_N_ON_H(N) (PCA9685_LEDX_ON_H + (4 * (N)))
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#define LED_N_ON_L(N) (PCA9685_LEDX_ON_L + (4 * (N)))
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#define LED_N_OFF_H(N) (PCA9685_LEDX_OFF_H + (4 * (N)))
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#define LED_N_OFF_L(N) (PCA9685_LEDX_OFF_L + (4 * (N)))
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struct pca9685 {
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struct pwm_chip chip;
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struct regmap *regmap;
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int active_cnt;
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};
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static inline struct pca9685 *to_pca(struct pwm_chip *chip)
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{
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return container_of(chip, struct pca9685, chip);
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}
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static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
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int duty_ns, int period_ns)
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{
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struct pca9685 *pca = to_pca(chip);
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unsigned long long duty;
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unsigned int reg;
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if (duty_ns < 1) {
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if (pwm->hwpwm >= PCA9685_MAXCHAN)
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reg = PCA9685_ALL_LED_OFF_H;
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else
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reg = LED_N_OFF_H(pwm->hwpwm);
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regmap_write(pca->regmap, reg, LED_FULL);
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return 0;
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}
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if (duty_ns == period_ns) {
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if (pwm->hwpwm >= PCA9685_MAXCHAN)
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reg = PCA9685_ALL_LED_ON_H;
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else
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reg = LED_N_ON_H(pwm->hwpwm);
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regmap_write(pca->regmap, reg, LED_FULL);
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return 0;
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}
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duty = 4096 * (unsigned long long)duty_ns;
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duty = DIV_ROUND_UP_ULL(duty, period_ns);
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if (pwm->hwpwm >= PCA9685_MAXCHAN)
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reg = PCA9685_ALL_LED_OFF_L;
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else
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reg = LED_N_OFF_L(pwm->hwpwm);
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regmap_write(pca->regmap, reg, (int)duty & 0xff);
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if (pwm->hwpwm >= PCA9685_MAXCHAN)
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reg = PCA9685_ALL_LED_OFF_H;
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else
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reg = LED_N_OFF_H(pwm->hwpwm);
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regmap_write(pca->regmap, reg, ((int)duty >> 8) & 0xf);
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return 0;
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}
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static int pca9685_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct pca9685 *pca = to_pca(chip);
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unsigned int reg;
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/*
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* The PWM subsystem does not support a pre-delay.
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* So, set the ON-timeout to 0
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*/
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if (pwm->hwpwm >= PCA9685_MAXCHAN)
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reg = PCA9685_ALL_LED_ON_L;
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else
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reg = LED_N_ON_L(pwm->hwpwm);
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regmap_write(pca->regmap, reg, 0);
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if (pwm->hwpwm >= PCA9685_MAXCHAN)
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reg = PCA9685_ALL_LED_ON_H;
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else
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reg = LED_N_ON_H(pwm->hwpwm);
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regmap_write(pca->regmap, reg, 0);
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/*
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* Clear the full-off bit.
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* It has precedence over the others and must be off.
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*/
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if (pwm->hwpwm >= PCA9685_MAXCHAN)
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reg = PCA9685_ALL_LED_OFF_H;
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else
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reg = LED_N_OFF_H(pwm->hwpwm);
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regmap_update_bits(pca->regmap, reg, LED_FULL, 0x0);
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return 0;
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}
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static void pca9685_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct pca9685 *pca = to_pca(chip);
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unsigned int reg;
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if (pwm->hwpwm >= PCA9685_MAXCHAN)
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reg = PCA9685_ALL_LED_OFF_H;
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else
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reg = LED_N_OFF_H(pwm->hwpwm);
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regmap_write(pca->regmap, reg, LED_FULL);
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/* Clear the LED_OFF counter. */
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if (pwm->hwpwm >= PCA9685_MAXCHAN)
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reg = PCA9685_ALL_LED_OFF_L;
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else
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reg = LED_N_OFF_L(pwm->hwpwm);
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regmap_write(pca->regmap, reg, 0x0);
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}
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static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct pca9685 *pca = to_pca(chip);
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if (pca->active_cnt++ == 0)
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return regmap_update_bits(pca->regmap, PCA9685_MODE1,
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MODE1_SLEEP, 0x0);
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return 0;
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}
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static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct pca9685 *pca = to_pca(chip);
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if (--pca->active_cnt == 0)
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regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP,
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0x1);
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}
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static const struct pwm_ops pca9685_pwm_ops = {
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.enable = pca9685_pwm_enable,
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.disable = pca9685_pwm_disable,
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.config = pca9685_pwm_config,
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.request = pca9685_pwm_request,
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.free = pca9685_pwm_free,
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};
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static struct regmap_config pca9685_regmap_i2c_config = {
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.reg_bits = 8,
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.val_bits = 8,
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.max_register = PCA9685_NUMREGS,
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.cache_type = REGCACHE_NONE,
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};
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static int pca9685_pwm_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct device_node *np = client->dev.of_node;
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struct pca9685 *pca;
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int ret;
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int mode2;
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pca = devm_kzalloc(&client->dev, sizeof(*pca), GFP_KERNEL);
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if (!pca)
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return -ENOMEM;
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pca->regmap = devm_regmap_init_i2c(client, &pca9685_regmap_i2c_config);
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if (IS_ERR(pca->regmap)) {
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ret = PTR_ERR(pca->regmap);
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dev_err(&client->dev, "Failed to initialize register map: %d\n",
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ret);
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return ret;
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}
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i2c_set_clientdata(client, pca);
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regmap_read(pca->regmap, PCA9685_MODE2, &mode2);
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if (of_property_read_bool(np, "invert"))
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mode2 |= MODE2_INVRT;
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else
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mode2 &= ~MODE2_INVRT;
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if (of_property_read_bool(np, "open-drain"))
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mode2 &= ~MODE2_OUTDRV;
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else
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mode2 |= MODE2_OUTDRV;
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regmap_write(pca->regmap, PCA9685_MODE2, mode2);
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/* clear all "full off" bits */
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regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_L, 0);
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regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, 0);
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pca->chip.ops = &pca9685_pwm_ops;
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/* add an extra channel for ALL_LED */
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pca->chip.npwm = PCA9685_MAXCHAN + 1;
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pca->chip.dev = &client->dev;
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pca->chip.base = -1;
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pca->chip.can_sleep = true;
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return pwmchip_add(&pca->chip);
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}
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static int pca9685_pwm_remove(struct i2c_client *client)
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{
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struct pca9685 *pca = i2c_get_clientdata(client);
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regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP, 0x1);
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return pwmchip_remove(&pca->chip);
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}
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static const struct i2c_device_id pca9685_id[] = {
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{ "pca9685", 0 },
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{ /* sentinel */ },
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};
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MODULE_DEVICE_TABLE(i2c, pca9685_id);
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static const struct of_device_id pca9685_dt_ids[] = {
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{ .compatible = "nxp,pca9685-pwm", },
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{ /* sentinel */ }
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};
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MODULE_DEVICE_TABLE(of, pca9685_dt_ids);
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static struct i2c_driver pca9685_i2c_driver = {
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.driver = {
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.name = "pca9685-pwm",
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.owner = THIS_MODULE,
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.of_match_table = pca9685_dt_ids,
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},
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.probe = pca9685_pwm_probe,
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.remove = pca9685_pwm_remove,
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.id_table = pca9685_id,
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};
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module_i2c_driver(pca9685_i2c_driver);
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MODULE_AUTHOR("Steffen Trumtrar <s.trumtrar@pengutronix.de>");
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MODULE_DESCRIPTION("PWM driver for PCA9685");
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MODULE_LICENSE("GPL");
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