diff options
| -rw-r--r-- | Documentation/devicetree/bindings/pwm/nxp,pca9685-pwm.txt | 27 | ||||
| -rw-r--r-- | drivers/pwm/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/pwm/Makefile | 1 | ||||
| -rw-r--r-- | drivers/pwm/pwm-pca9685.c | 298 |
4 files changed, 335 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/pwm/nxp,pca9685-pwm.txt b/Documentation/devicetree/bindings/pwm/nxp,pca9685-pwm.txt new file mode 100644 index 000000000000..1e3dfe7a4894 --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/nxp,pca9685-pwm.txt @@ -0,0 +1,27 @@ +NXP PCA9685 16-channel 12-bit PWM LED controller +================================================ + +Required properties: + - compatible: "nxp,pca9685-pwm" + - #pwm-cells: should be 2. The first cell specifies the per-chip index + of the PWM to use and the second cell is the period in nanoseconds. + The index 16 is the ALLCALL channel, that sets all PWM channels at the same + time. + +Optional properties: + - invert (bool): boolean to enable inverted logic + - open-drain (bool): boolean to configure outputs with open-drain structure; + if omitted use totem-pole structure + +Example: + +For LEDs that are directly connected to the PCA, the following setting is +applicable: + +pca: pca@41 { + compatible = "nxp,pca9685-pwm"; + #pwm-cells = <2>; + reg = <0x41>; + invert; + open-drain; +}; diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 115b64453493..d3fe3205d296 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -97,6 +97,15 @@ config PWM_MXS To compile this driver as a module, choose M here: the module will be called pwm-mxs. +config PWM_PCA9685 + tristate "NXP PCA9685 PWM driver" + depends on OF && REGMAP_I2C + help + Generic PWM framework driver for NXP PCA9685 LED controller. + + To compile this driver as a module, choose M here: the module + will be called pwm-pca9685. + config PWM_PUV3 tristate "PKUnity NetBook-0916 PWM support" depends on ARCH_PUV3 diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index 94ba21e24bd6..b3afc0a1800b 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -6,6 +6,7 @@ obj-$(CONFIG_PWM_IMX) += pwm-imx.o obj-$(CONFIG_PWM_JZ4740) += pwm-jz4740.o obj-$(CONFIG_PWM_LPC32XX) += pwm-lpc32xx.o obj-$(CONFIG_PWM_MXS) += pwm-mxs.o +obj-$(CONFIG_PWM_PCA9685) += pwm-pca9685.o obj-$(CONFIG_PWM_PUV3) += pwm-puv3.o obj-$(CONFIG_PWM_PXA) += pwm-pxa.o obj-$(CONFIG_PWM_SAMSUNG) += pwm-samsung.o diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c new file mode 100644 index 000000000000..2afc9043550a --- /dev/null +++ b/drivers/pwm/pwm-pca9685.c @@ -0,0 +1,298 @@ +/* + * Driver for PCA9685 16-channel 12-bit PWM LED controller + * + * Copyright (C) 2013 Steffen Trumtrar <s.trumtrar@pengutronix.de> + * + * based on the pwm-twl-led.c driver + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/pwm.h> +#include <linux/regmap.h> +#include <linux/slab.h> + +#define PCA9685_MODE1 0x00 +#define PCA9685_MODE2 0x01 +#define PCA9685_SUBADDR1 0x02 +#define PCA9685_SUBADDR2 0x03 +#define PCA9685_SUBADDR3 0x04 +#define PCA9685_ALLCALLADDR 0x05 +#define PCA9685_LEDX_ON_L 0x06 +#define PCA9685_LEDX_ON_H 0x07 +#define PCA9685_LEDX_OFF_L 0x08 +#define PCA9685_LEDX_OFF_H 0x09 + +#define PCA9685_ALL_LED_ON_L 0xFA +#define PCA9685_ALL_LED_ON_H 0xFB +#define PCA9685_ALL_LED_OFF_L 0xFC +#define PCA9685_ALL_LED_OFF_H 0xFD +#define PCA9685_PRESCALE 0xFE + +#define PCA9685_NUMREGS 0xFF +#define PCA9685_MAXCHAN 0x10 + +#define LED_FULL (1 << 4) +#define MODE1_SLEEP (1 << 4) +#define MODE2_INVRT (1 << 4) +#define MODE2_OUTDRV (1 << 2) + +#define LED_N_ON_H(N) (PCA9685_LEDX_ON_H + (4 * (N))) +#define LED_N_ON_L(N) (PCA9685_LEDX_ON_L + (4 * (N))) +#define LED_N_OFF_H(N) (PCA9685_LEDX_OFF_H + (4 * (N))) +#define LED_N_OFF_L(N) (PCA9685_LEDX_OFF_L + (4 * (N))) + +struct pca9685 { + struct pwm_chip chip; + struct regmap *regmap; + int active_cnt; +}; + +static inline struct pca9685 *to_pca(struct pwm_chip *chip) +{ + return container_of(chip, struct pca9685, chip); +} + +static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, + int duty_ns, int period_ns) +{ + struct pca9685 *pca = to_pca(chip); + unsigned long long duty; + unsigned int reg; + + if (duty_ns < 1) { + if (pwm->hwpwm >= PCA9685_MAXCHAN) + reg = PCA9685_ALL_LED_OFF_H; + else + reg = LED_N_OFF_H(pwm->hwpwm); + + regmap_write(pca->regmap, reg, LED_FULL); + + return 0; + } + + if (duty_ns == period_ns) { + if (pwm->hwpwm >= PCA9685_MAXCHAN) + reg = PCA9685_ALL_LED_ON_H; + else + reg = LED_N_ON_H(pwm->hwpwm); + + regmap_write(pca->regmap, reg, LED_FULL); + + return 0; + } + + duty = 4096 * (unsigned long long)duty_ns; + duty = DIV_ROUND_UP_ULL(duty, period_ns); + + if (pwm->hwpwm >= PCA9685_MAXCHAN) + reg = PCA9685_ALL_LED_OFF_L; + else + reg = LED_N_OFF_L(pwm->hwpwm); + + regmap_write(pca->regmap, reg, (int)duty & 0xff); + + if (pwm->hwpwm >= PCA9685_MAXCHAN) + reg = PCA9685_ALL_LED_OFF_H; + else + reg = LED_N_OFF_H(pwm->hwpwm); + + regmap_write(pca->regmap, reg, ((int)duty >> 8) & 0xf); + + return 0; +} + +static int pca9685_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct pca9685 *pca = to_pca(chip); + unsigned int reg; + + /* + * The PWM subsystem does not support a pre-delay. + * So, set the ON-timeout to 0 + */ + if (pwm->hwpwm >= PCA9685_MAXCHAN) + reg = PCA9685_ALL_LED_ON_L; + else + reg = LED_N_ON_L(pwm->hwpwm); + + regmap_write(pca->regmap, reg, 0); + + if (pwm->hwpwm >= PCA9685_MAXCHAN) + reg = PCA9685_ALL_LED_ON_H; + else + reg = LED_N_ON_H(pwm->hwpwm); + + regmap_write(pca->regmap, reg, 0); + + /* + * Clear the full-off bit. + * It has precedence over the others and must be off. + */ + if (pwm->hwpwm >= PCA9685_MAXCHAN) + reg = PCA9685_ALL_LED_OFF_H; + else + reg = LED_N_OFF_H(pwm->hwpwm); + + regmap_update_bits(pca->regmap, reg, LED_FULL, 0x0); + + return 0; +} + +static void pca9685_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct pca9685 *pca = to_pca(chip); + unsigned int reg; + + if (pwm->hwpwm >= PCA9685_MAXCHAN) + reg = PCA9685_ALL_LED_OFF_H; + else + reg = LED_N_OFF_H(pwm->hwpwm); + + regmap_write(pca->regmap, reg, LED_FULL); + + /* Clear the LED_OFF counter. */ + if (pwm->hwpwm >= PCA9685_MAXCHAN) + reg = PCA9685_ALL_LED_OFF_L; + else + reg = LED_N_OFF_L(pwm->hwpwm); + + regmap_write(pca->regmap, reg, 0x0); +} + +static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct pca9685 *pca = to_pca(chip); + + if (pca->active_cnt++ == 0) + return regmap_update_bits(pca->regmap, PCA9685_MODE1, + MODE1_SLEEP, 0x0); + + return 0; +} + +static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct pca9685 *pca = to_pca(chip); + + if (--pca->active_cnt == 0) + regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP, + 0x1); +} + +static const struct pwm_ops pca9685_pwm_ops = { + .enable = pca9685_pwm_enable, + .disable = pca9685_pwm_disable, + .config = pca9685_pwm_config, + .request = pca9685_pwm_request, + .free = pca9685_pwm_free, +}; + +static struct regmap_config pca9685_regmap_i2c_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = PCA9685_NUMREGS, + .cache_type = REGCACHE_NONE, +}; + +static int pca9685_pwm_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct device_node *np = client->dev.of_node; + struct pca9685 *pca; + int ret; + int mode2; + + pca = devm_kzalloc(&client->dev, sizeof(*pca), GFP_KERNEL); + if (!pca) + return -ENOMEM; + + pca->regmap = devm_regmap_init_i2c(client, &pca9685_regmap_i2c_config); + if (IS_ERR(pca->regmap)) { + ret = PTR_ERR(pca->regmap); + dev_err(&client->dev, "Failed to initialize register map: %d\n", + ret); + return ret; + } + + i2c_set_clientdata(client, pca); + + regmap_read(pca->regmap, PCA9685_MODE2, &mode2); + + if (of_property_read_bool(np, "invert")) + mode2 |= MODE2_INVRT; + else + mode2 &= ~MODE2_INVRT; + + if (of_property_read_bool(np, "open-drain")) + mode2 &= ~MODE2_OUTDRV; + else + mode2 |= MODE2_OUTDRV; + + regmap_write(pca->regmap, PCA9685_MODE2, mode2); + + /* clear all "full off" bits */ + regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_L, 0); + regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, 0); + + pca->chip.ops = &pca9685_pwm_ops; + /* add an extra channel for ALL_LED */ + pca->chip.npwm = PCA9685_MAXCHAN + 1; + + pca->chip.dev = &client->dev; + pca->chip.base = -1; + pca->chip.can_sleep = true; + + return pwmchip_add(&pca->chip); +} + +static int pca9685_pwm_remove(struct i2c_client *client) +{ + struct pca9685 *pca = i2c_get_clientdata(client); + + regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP, 0x1); + + return pwmchip_remove(&pca->chip); +} + +static const struct i2c_device_id pca9685_id[] = { + { "pca9685", 0 }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(i2c, pca9685_id); + +static const struct of_device_id pca9685_dt_ids[] = { + { .compatible = "nxp,pca9685-pwm", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, pca9685_dt_ids); + +static struct i2c_driver pca9685_i2c_driver = { + .driver = { + .name = "pca9685-pwm", + .owner = THIS_MODULE, + .of_match_table = pca9685_dt_ids, + }, + .probe = pca9685_pwm_probe, + .remove = pca9685_pwm_remove, + .id_table = pca9685_id, +}; + +module_i2c_driver(pca9685_i2c_driver); + +MODULE_AUTHOR("Steffen Trumtrar <s.trumtrar@pengutronix.de>"); +MODULE_DESCRIPTION("PWM driver for PCA9685"); +MODULE_LICENSE("GPL"); |