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-rw-r--r--drivers/leds/leds-ti-lmu-common.c153
1 files changed, 153 insertions, 0 deletions
diff --git a/drivers/leds/leds-ti-lmu-common.c b/drivers/leds/leds-ti-lmu-common.c
new file mode 100644
index 000000000..d7f10ad72
--- /dev/null
+++ b/drivers/leds/leds-ti-lmu-common.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright 2015 Texas Instruments
+// Copyright 2018 Sebastian Reichel
+// Copyright 2018 Pavel Machek <pavel@ucw.cz>
+// TI LMU LED common framework, based on previous work from
+// Milo Kim <milo.kim@ti.com>
+
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/of_device.h>
+
+#include <linux/leds-ti-lmu-common.h>
+
+static const unsigned int ramp_table[16] = {2048, 262000, 524000, 1049000,
+ 2090000, 4194000, 8389000, 16780000, 33550000,
+ 41940000, 50330000, 58720000, 67110000,
+ 83880000, 100660000, 117440000};
+
+static int ti_lmu_common_update_brightness(struct ti_lmu_bank *lmu_bank,
+ int brightness)
+{
+ struct regmap *regmap = lmu_bank->regmap;
+ u8 reg, val;
+ int ret;
+
+ /*
+ * Brightness register update
+ *
+ * 11 bit dimming: update LSB bits and write MSB byte.
+ * MSB brightness should be shifted.
+ * 8 bit dimming: write MSB byte.
+ */
+ if (lmu_bank->max_brightness == MAX_BRIGHTNESS_11BIT) {
+ reg = lmu_bank->lsb_brightness_reg;
+ ret = regmap_update_bits(regmap, reg,
+ LMU_11BIT_LSB_MASK,
+ brightness);
+ if (ret)
+ return ret;
+
+ val = brightness >> LMU_11BIT_MSB_SHIFT;
+ } else {
+ val = brightness;
+ }
+
+ reg = lmu_bank->msb_brightness_reg;
+
+ return regmap_write(regmap, reg, val);
+}
+
+int ti_lmu_common_set_brightness(struct ti_lmu_bank *lmu_bank, int brightness)
+{
+ return ti_lmu_common_update_brightness(lmu_bank, brightness);
+}
+EXPORT_SYMBOL(ti_lmu_common_set_brightness);
+
+static unsigned int ti_lmu_common_convert_ramp_to_index(unsigned int usec)
+{
+ int size = ARRAY_SIZE(ramp_table);
+ int i;
+
+ if (usec <= ramp_table[0])
+ return 0;
+
+ if (usec > ramp_table[size - 1])
+ return size - 1;
+
+ for (i = 1; i < size; i++) {
+ if (usec == ramp_table[i])
+ return i;
+
+ /* Find an approximate index by looking up the table */
+ if (usec > ramp_table[i - 1] && usec < ramp_table[i]) {
+ if (usec - ramp_table[i - 1] < ramp_table[i] - usec)
+ return i - 1;
+ else
+ return i;
+ }
+ }
+
+ return 0;
+}
+
+int ti_lmu_common_set_ramp(struct ti_lmu_bank *lmu_bank)
+{
+ struct regmap *regmap = lmu_bank->regmap;
+ u8 ramp, ramp_up, ramp_down;
+
+ if (lmu_bank->ramp_up_usec == 0 && lmu_bank->ramp_down_usec == 0) {
+ ramp_up = 0;
+ ramp_down = 0;
+ } else {
+ ramp_up = ti_lmu_common_convert_ramp_to_index(lmu_bank->ramp_up_usec);
+ ramp_down = ti_lmu_common_convert_ramp_to_index(lmu_bank->ramp_down_usec);
+ }
+
+ ramp = (ramp_up << 4) | ramp_down;
+
+ return regmap_write(regmap, lmu_bank->runtime_ramp_reg, ramp);
+
+}
+EXPORT_SYMBOL(ti_lmu_common_set_ramp);
+
+int ti_lmu_common_get_ramp_params(struct device *dev,
+ struct fwnode_handle *child,
+ struct ti_lmu_bank *lmu_data)
+{
+ int ret;
+
+ ret = fwnode_property_read_u32(child, "ramp-up-us",
+ &lmu_data->ramp_up_usec);
+ if (ret)
+ dev_warn(dev, "ramp-up-us property missing\n");
+
+
+ ret = fwnode_property_read_u32(child, "ramp-down-us",
+ &lmu_data->ramp_down_usec);
+ if (ret)
+ dev_warn(dev, "ramp-down-us property missing\n");
+
+ return 0;
+}
+EXPORT_SYMBOL(ti_lmu_common_get_ramp_params);
+
+int ti_lmu_common_get_brt_res(struct device *dev, struct fwnode_handle *child,
+ struct ti_lmu_bank *lmu_data)
+{
+ int ret;
+
+ ret = device_property_read_u32(dev, "ti,brightness-resolution",
+ &lmu_data->max_brightness);
+ if (ret)
+ ret = fwnode_property_read_u32(child,
+ "ti,brightness-resolution",
+ &lmu_data->max_brightness);
+ if (lmu_data->max_brightness <= 0) {
+ lmu_data->max_brightness = MAX_BRIGHTNESS_8BIT;
+ return ret;
+ }
+
+ if (lmu_data->max_brightness > MAX_BRIGHTNESS_11BIT)
+ lmu_data->max_brightness = MAX_BRIGHTNESS_11BIT;
+
+
+ return 0;
+}
+EXPORT_SYMBOL(ti_lmu_common_get_brt_res);
+
+MODULE_DESCRIPTION("TI LMU common LED framework");
+MODULE_AUTHOR("Sebastian Reichel");
+MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("ti-lmu-led-common");