auxdisplay: Add driver for MAX695x 7-segment LED controllers

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

Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

diff --git a/drivers/auxdisplay/Kconfig b/drivers/auxdisplay/Kconfig
index d944d5298eca822215c21d8a902766495d11c83b..d4be0a3695ceb96b8770b4f3dd12710e8a764397 100644 (file)
--- a/drivers/auxdisplay/Kconfig
+++ b/drivers/auxdisplay/Kconfig
@@ -177,6 +177,20 @@ 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"
+       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):
+         - MAX6958
+         - MAX6959 (input support)
+
+         This driver can also be built as a module. If so, the module
+         will be called max6959.
+
 config LCD2S
        tristate "lcd2s 20x4 character display over I2C console"
        depends on I2C

diff --git a/drivers/auxdisplay/Makefile b/drivers/auxdisplay/Makefile
index 6968ed4d3f0a89300e1d77df7b462a589ce05165..a725010ca6514078ab9d617bd58a6745406b2274 100644 (file)
--- a/drivers/auxdisplay/Makefile
+++ b/drivers/auxdisplay/Makefile
@@ -14,3 +14,4 @@ obj-$(CONFIG_HT16K33)         += ht16k33.o
 obj-$(CONFIG_PARPORT_PANEL)    += panel.o
 obj-$(CONFIG_LCD2S)            += lcd2s.o
 obj-$(CONFIG_LINEDISP)         += line-display.o
+obj-$(CONFIG_MAX6959)          += max6959.o

diff --git a/drivers/auxdisplay/max6959.c b/drivers/auxdisplay/max6959.c
new file mode 100644 (file)
index 0000000..5519c01
--- /dev/null
+++ b/drivers/auxdisplay/max6959.c
@@ -0,0 +1,194 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MAX6958/6959 7-segment LED display controller
+ * 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
+
+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->buf;
+       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, &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");
+MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(LINEDISP);