[v3,9/9] auxdisplay: Add driver for MAX695x 7-segment LED controllers
Commit Message
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 | 194 +++++++++++++++++++++++++++++++++++
3 files changed, 209 insertions(+)
create mode 100644 drivers/auxdisplay/max6959.c
Comments
Hi Andy,
On Mon, Feb 19, 2024 at 6:03 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
> Add initial driver for the MAX6958 and MAX6959 7-segment LED
> controllers.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Thanks for your patch!
LGTM, so
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
> --- /dev/null
> +++ b/drivers/auxdisplay/max6959.c
> +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;
for (unsigned int i = 0; i < linedisp->num_chars; i++) { ... }
> +
> + regmap_bulk_write(priv->regmap, REG_DIGIT(0), buf, ARRAY_SIZE(buf));
linedisp->num_chars
> +}
> +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);
+ device_property_read_u32(dev, "display-width-chars", ...) handling.
Gr{oetje,eeting}s,
Geert
On Mon, Feb 26, 2024 at 05:01:46PM +0100, Geert Uytterhoeven wrote:
> On Mon, Feb 19, 2024 at 6:03 PM Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> > Add initial driver for the MAX6958 and MAX6959 7-segment LED
> > controllers.
> LGTM, so
> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Thanks, but see below.
..
> > + 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;
>
> for (unsigned int i = 0; i < linedisp->num_chars; i++) { ... }
>
> > +
> > + regmap_bulk_write(priv->regmap, REG_DIGIT(0), buf, ARRAY_SIZE(buf));
>
> linedisp->num_chars
Maybe, but then we probably want to synchronize the 4 there and here as we
can't have VLA on stack.
> > +}
..
> > + ret = linedisp_register(&priv->linedisp, dev, 4, &max6959_linedisp_ops);
>
> + device_property_read_u32(dev, "display-width-chars", ...) handling.
Not sure it should be part of this series.
Hi Andy,
On Mon, Feb 26, 2024 at 5:17 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
> On Mon, Feb 26, 2024 at 05:01:46PM +0100, Geert Uytterhoeven wrote:
> > On Mon, Feb 19, 2024 at 6:03 PM Andy Shevchenko
> > <andriy.shevchenko@linux.intel.com> wrote:
> > > Add initial driver for the MAX6958 and MAX6959 7-segment LED
> > > controllers.
>
> > LGTM, so
> > Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
>
> Thanks, but see below.
>
> ...
>
> > > + 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;
> >
> > for (unsigned int i = 0; i < linedisp->num_chars; i++) { ... }
> >
> > > +
> > > + regmap_bulk_write(priv->regmap, REG_DIGIT(0), buf, ARRAY_SIZE(buf));
> >
> > linedisp->num_chars
>
> Maybe, but then we probably want to synchronize the 4 there and here as we
> can't have VLA on stack.
You can still keep the maximum buf[4], so no VLA needed?
>
> > > +}
>
> ...
>
> > > + ret = linedisp_register(&priv->linedisp, dev, 4, &max6959_linedisp_ops);
> >
> > + device_property_read_u32(dev, "display-width-chars", ...) handling.
>
> Not sure it should be part of this series.
Fair enough, so please go ahead without.
Even "display-width-chars" might not cover all cases, as a board
may use any subset of the 4 DIGn signals, even in any order...
Gr{oetje,eeting}s,
Geert
On Mon, Feb 26, 2024 at 05:01:46PM +0100, Geert Uytterhoeven wrote:
> On Mon, Feb 19, 2024 at 6:03 PM Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> > Add initial driver for the MAX6958 and MAX6959 7-segment LED
> > controllers.
..
> LGTM, so
> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
As per discussion, let consider maximum digits as a next feature coming later
on. I'll take this tag, tell me if I shouldn't.
Thank you!
@@ -59,6 +59,20 @@ config LCD2S
is a simple single color character display. You have to connect it
to an I2C bus.
+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.
+
menuconfig PARPORT_PANEL
tristate "Parallel port LCD/Keypad Panel support"
depends on PARPORT
@@ -15,5 +15,6 @@ 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
new file mode 100644
@@ -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);