summaryrefslogtreecommitdiffstats
path: root/drivers/pwm/pwm-pca9685.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2013-07-10 11:14:56 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-10 11:14:56 -0700
commit34ae0a6f05aee9f51fca17001b4a90703d434ae1 (patch)
tree3ccc8bedae647eb37f46e8ff9f39cdcd84a2f2ac /drivers/pwm/pwm-pca9685.c
parent7d3107d26b522a0fe92af6279256fa65fe3db771 (diff)
parentb388f15fd14c3ae62deb9a059464aa99b524ea4a (diff)
downloadop-kernel-dev-34ae0a6f05aee9f51fca17001b4a90703d434ae1.zip
op-kernel-dev-34ae0a6f05aee9f51fca17001b4a90703d434ae1.tar.gz
Merge tag 'for-3.11-rc1' of git://gitorious.org/linux-pwm/linux-pwm
Pull pwm changes from Thierry Reding: "A new driver supports driving PWM signals using the TPU unit found on various Renesas SoCs. Furthermore support is added for the NXP PCA9685 LED controller. Another big chunk is the sysfs interface which has been in the works for quite some time. The remaining patches are a random assortment of cleanups and fixes" * tag 'for-3.11-rc1' of git://gitorious.org/linux-pwm/linux-pwm: pwm: pwm-tiehrpwm: Use clk_enable/disable instead clk_prepare/unprepare. pwm: pca9685: Fix wrong argument to set MODE1_SLEEP bit pwm: renesas-tpu: Add MODULE_ALIAS to make module auto loading work pwm: renesas-tpu: fix return value check in tpu_probe() pwm: Add Renesas TPU PWM driver pwm: Add sysfs interface pwm: Fill in missing .owner fields pwm: add pca9685 driver pwm: atmel-tcb: prepare clk before calling enable pwm: devm: alloc correct pointer size pwm: mxs: Let device core handle pinctrl MAINTAINERS: Update PWM subsystem entry
Diffstat (limited to 'drivers/pwm/pwm-pca9685.c')
-rw-r--r--drivers/pwm/pwm-pca9685.c300
1 files changed, 300 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c
new file mode 100644
index 0000000..3fb775d
--- /dev/null
+++ b/drivers/pwm/pwm-pca9685.c
@@ -0,0 +1,300 @@
+/*
+ * 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,
+ MODE1_SLEEP);
+}
+
+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,
+ .owner = THIS_MODULE,
+};
+
+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,
+ MODE1_SLEEP);
+
+ 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");
OpenPOWER on IntegriCloud