[PATCH v1 15/15] auxdisplay: Add driver for MAX695x 7-segment LED controllers

Andy Shevchenko
2024-02-08T18:49:40Z

Add initial driver for the MAX6958 and MAX6959 7-segment LED
controllers.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
drivers/auxdisplay/Kconfig | 14 +++
drivers/auxdisplay/Makefile | 1 +
drivers/auxdisplay/max6959.c | 200 +++++++++++++++++++++++++++++++++++
3 files changed, 215 insertions(+)
create mode 100644 drivers/auxdisplay/max6959.c

diff --git a/drivers/auxdisplay/Kconfig b/drivers/auxdisplay/Kconfig
index a34a9a52158f..079d58bb0293 100644
--- a/drivers/auxdisplay/Kconfig
+++ b/drivers/auxdisplay/Kconfig
@@ -187,6 +187,20 @@ config HT16K33
Say yes here to add support for Holtek HT16K33, RAM mapping 16*8
LED controller driver with keyscan.

+config MAX6959
+ tristate "Maxim MAX6958/6959 7-segment LED controller with keyscan"
+ depends on I2C
+ select REGMAP_I2C
+ select LINEDISP
+ help
+ If you say yes here you get support for the following Maxim chips
+ (I2C 7-segment LED display controller with keyscan):
+ - MAX6958
+ - MAX6959 (debounce support)
+
+ This driver can also be built as a module. If so, the module
+ will be called max6959.
+
config ARM_CHARLCD
bool "ARM Ltd. Character LCD Driver"
depends on PLAT_VERSATILE
diff --git a/drivers/auxdisplay/Makefile b/drivers/auxdisplay/Makefile
index 43bad850481c..f62a258809ef 100644
--- a/drivers/auxdisplay/Makefile
+++ b/drivers/auxdisplay/Makefile
@@ -12,5 +12,6 @@ obj-$(CONFIG_CFAG12864B) += cfag12864b.o cfag12864bfb.o
obj-$(CONFIG_LINEDISP) += line-display.o
obj-$(CONFIG_IMG_ASCII_LCD) += img-ascii-lcd.o
obj-$(CONFIG_HT16K33) += ht16k33.o
+obj-$(CONFIG_MAX6959) += max6959.o
obj-$(CONFIG_ARM_CHARLCD) += arm-charlcd.o
obj-$(CONFIG_PARPORT_PANEL) += panel.o
diff --git a/drivers/auxdisplay/max6959.c b/drivers/auxdisplay/max6959.c
new file mode 100644
index 000000000000..0c5cbd16c3fe
--- /dev/null
+++ b/drivers/auxdisplay/max6959.c
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MAX6958/6959 7-segment LED display controller with keyscan
+ * Datasheet:
+ * https://www.analog.com/media/en/technical-documentation/data-sheets/MAX6958-MAX6959.pdf
+ *
+ * Copyright (c) 2024, Intel Corporation.
+ * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ */
+#include <linux/array_size.h>
+#include <linux/bitrev.h>
+#include <linux/bits.h>
+#include <linux/container_of.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+
+#include <linux/map_to_7segment.h>
+
+#include "line-display.h"
+
+/* Registers */
+#define REG_DECODE_MODE 0x01
+#define REG_INTENSITY 0x02
+#define REG_SCAN_LIMIT 0x03
+#define REG_CONFIGURATION 0x04
+#define REG_CONFIGURATION_S_BIT BIT(0)
+
+#define REG_DIGIT(x) (0x20 + (x))
+#define REG_DIGIT0 0x20
+#define REG_DIGIT1 0x21
+#define REG_DIGIT2 0x22
+#define REG_DIGIT3 0x23
+
+#define REG_SEGMENTS 0x24
+#define REG_MAX REG_SEGMENTS
+
+/* Defines */
+#define MIN_BRIGHTNESS 0x01
+#define MAX_BRIGHTNESS 0x40
+
+struct max6959_priv {
+ struct linedisp linedisp;
+
+ struct delayed_work work;
+
+ struct regmap *regmap;
+};
+
+static void max6959_disp_update(struct work_struct *work)
+{
+ struct max6959_priv *priv = container_of(work, struct max6959_priv, work.work);
+ struct linedisp *linedisp = &priv->linedisp;
+ struct linedisp_map *map = linedisp->map;
+ char *s = linedisp->curr;
+ u8 buf[4];
+
+ /* Map segments according to datasheet */
+ buf[0] = bitrev8(map_to_seg7(&map->map.seg7, *s++)) >> 1;
+ buf[1] = bitrev8(map_to_seg7(&map->map.seg7, *s++)) >> 1;
+ buf[2] = bitrev8(map_to_seg7(&map->map.seg7, *s++)) >> 1;
+ buf[3] = bitrev8(map_to_seg7(&map->map.seg7, *s++)) >> 1;
+
+ regmap_bulk_write(priv->regmap, REG_DIGIT(0), buf, ARRAY_SIZE(buf));
+}
+
+static int max6959_linedisp_get_map_type(struct linedisp *linedisp)
+{
+ struct max6959_priv *priv = container_of(linedisp, struct max6959_priv, linedisp);
+
+ INIT_DELAYED_WORK(&priv->work, max6959_disp_update);
+ return LINEDISP_MAP_SEG7;
+}
+
+static void max6959_linedisp_update(struct linedisp *linedisp)
+{
+ struct max6959_priv *priv = container_of(linedisp, struct max6959_priv, linedisp);
+
+ schedule_delayed_work(&priv->work, 0);
+}
+
+static const struct linedisp_ops max6959_linedisp_ops = {
+ .get_map_type = max6959_linedisp_get_map_type,
+ .update = max6959_linedisp_update,
+};
+
+static int max6959_enable(struct max6959_priv *priv, bool enable)
+{
+ u8 mask = REG_CONFIGURATION_S_BIT;
+ u8 value = enable ? mask : 0;
+
+ return regmap_update_bits(priv->regmap, REG_CONFIGURATION, mask, value);
+}
+
+static void max6959_power_off(void *priv)
+{
+ max6959_enable(priv, false);
+}
+
+static int max6959_power_on(struct max6959_priv *priv)
+{
+ struct device *dev = regmap_get_device(priv->regmap);
+ int ret;
+
+ ret = max6959_enable(priv, true);
+ if (ret)
+ return ret;
+
+ return devm_add_action_or_reset(dev, max6959_power_off, priv);
+}
+
+static const struct regmap_config max6959_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+
+ .max_register = REG_MAX,
+ .cache_type = REGCACHE_MAPLE,
+};
+
+static int max6959_i2c_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct max6959_priv *priv;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->regmap = devm_regmap_init_i2c(client, &max6959_regmap_config);
+ if (IS_ERR(priv->regmap))
+ return PTR_ERR(priv->regmap);
+
+ ret = max6959_power_on(priv);
+ if (ret)
+ return ret;
+
+ ret = linedisp_register(&priv->linedisp, dev, 4, NULL, &max6959_linedisp_ops);
+ if (ret)
+ return ret;
+
+ i2c_set_clientdata(client, priv);
+
+ return 0;
+}
+
+static void max6959_i2c_remove(struct i2c_client *client)
+{
+ struct max6959_priv *priv = i2c_get_clientdata(client);
+
+ cancel_delayed_work_sync(&priv->work);
+ linedisp_unregister(&priv->linedisp);
+}
+
+static int max6959_suspend(struct device *dev)
+{
+ return max6959_enable(dev_get_drvdata(dev), false);
+}
+
+static int max6959_resume(struct device *dev)
+{
+ return max6959_enable(dev_get_drvdata(dev), true);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(max6959_pm_ops, max6959_suspend, max6959_resume);
+
+static const struct i2c_device_id max6959_i2c_id[] = {
+ { "max6959" },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, max6959_i2c_id);
+
+static const struct of_device_id max6959_of_table[] = {
+ { .compatible = "maxim,max6959" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, max6959_of_table);
+
+static struct i2c_driver max6959_i2c_driver = {
+ .driver = {
+ .name = "max6959",
+ .pm = pm_sleep_ptr(&max6959_pm_ops),
+ .of_match_table = max6959_of_table,
+ },
+ .probe = max6959_i2c_probe,
+ .remove = max6959_i2c_remove,
+ .id_table = max6959_i2c_id,
+};
+module_i2c_driver(max6959_i2c_driver);
+
+MODULE_DESCRIPTION("MAX6958/6959 7-segment LED controller with keyscan");
+MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(LINEDISP);
--
2.43.0.rc1.1.gbec44491f096