[RFC 19/25] leds: tm1628: Add 7-segment display support
From: Andreas FÃrber
Date: Wed Dec 11 2019 - 22:41:09 EST
Detect DT child nodes covering more than one LED component and implement
a text to 7-segment display mapping.
Signed-off-by: Andreas FÃrber <afaerber@xxxxxxx>
---
drivers/leds/leds-tm1628.c | 230 ++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 229 insertions(+), 1 deletion(-)
diff --git a/drivers/leds/leds-tm1628.c b/drivers/leds/leds-tm1628.c
index 8a8fd1562853..e2c2a5d91596 100644
--- a/drivers/leds/leds-tm1628.c
+++ b/drivers/leds/leds-tm1628.c
@@ -47,6 +47,15 @@ struct tm1628_info {
int default_pwm;
};
+struct tm1628_segment {
+ u32 grid;
+ u32 seg;
+};
+
+struct tm1628_display {
+ struct tm1628_segment segments[8];
+};
+
struct tm1628_led {
struct led_classdev leddev;
struct tm1628 *ctrl;
@@ -62,6 +71,8 @@ struct tm1628 {
int mode_index;
int pwm_index;
u8 data[14];
+ unsigned int num_displays;
+ struct tm1628_display *displays;
unsigned int num_leds;
struct tm1628_led leds[];
};
@@ -253,6 +264,215 @@ static int tm1628_register_led(struct tm1628 *s,
return devm_led_classdev_register_ext(dev, &led->leddev, &init_data);
}
+#define SSD_TOP BIT(0)
+#define SSD_TOP_RIGHT BIT(1)
+#define SSD_BOTTOM_RIGHT BIT(2)
+#define SSD_BOTTOM BIT(3)
+#define SSD_BOTTOM_LEFT BIT(4)
+#define SSD_TOP_LEFT BIT(5)
+#define SSD_MIDDLE BIT(6)
+#define SSD_DOT BIT(7)
+
+struct tm1628_ssd_char {
+ char ch;
+ u8 segs;
+};
+
+static const struct tm1628_ssd_char tm1628_char_ssd_map[] = {
+ { '0', SSD_TOP | SSD_TOP_LEFT | SSD_TOP_RIGHT |
+ SSD_BOTTOM_LEFT | SSD_BOTTOM_RIGHT | SSD_BOTTOM },
+ { '1', SSD_TOP_RIGHT | SSD_BOTTOM_RIGHT },
+ { '2', SSD_TOP | SSD_TOP_RIGHT | SSD_MIDDLE | SSD_BOTTOM_LEFT | SSD_BOTTOM },
+ { '3', SSD_TOP | SSD_TOP_RIGHT | SSD_MIDDLE | SSD_BOTTOM_RIGHT | SSD_BOTTOM },
+ { '4', SSD_TOP_LEFT | SSD_TOP_RIGHT | SSD_MIDDLE | SSD_BOTTOM_RIGHT },
+ { '5', SSD_TOP | SSD_TOP_LEFT | SSD_MIDDLE | SSD_BOTTOM_RIGHT | SSD_BOTTOM },
+ { '6', SSD_TOP | SSD_TOP_LEFT | SSD_MIDDLE | SSD_BOTTOM_LEFT | SSD_BOTTOM_RIGHT | SSD_BOTTOM },
+ { '7', SSD_TOP | SSD_TOP_RIGHT | SSD_BOTTOM_RIGHT },
+ { '8', SSD_TOP | SSD_TOP_LEFT | SSD_TOP_RIGHT | SSD_MIDDLE |
+ SSD_BOTTOM_LEFT | SSD_BOTTOM_RIGHT | SSD_BOTTOM },
+ { '9', SSD_TOP | SSD_TOP_LEFT | SSD_TOP_RIGHT | SSD_MIDDLE |
+ SSD_BOTTOM_RIGHT | SSD_BOTTOM },
+ { 'A', SSD_TOP | SSD_TOP_LEFT | SSD_TOP_RIGHT | SSD_MIDDLE |
+ SSD_BOTTOM_LEFT | SSD_BOTTOM_RIGHT },
+ { 'B', SSD_TOP | SSD_TOP_LEFT | SSD_TOP_RIGHT | SSD_MIDDLE |
+ SSD_BOTTOM_LEFT | SSD_BOTTOM_RIGHT | SSD_BOTTOM },
+ { 'C', SSD_TOP | SSD_TOP_LEFT | SSD_BOTTOM_LEFT | SSD_BOTTOM },
+ { 'D', SSD_TOP | SSD_TOP_LEFT | SSD_TOP_RIGHT |
+ SSD_BOTTOM_LEFT | SSD_BOTTOM_RIGHT | SSD_BOTTOM },
+ { 'E', SSD_TOP | SSD_TOP_LEFT | SSD_MIDDLE | SSD_BOTTOM_LEFT | SSD_BOTTOM },
+ { 'F', SSD_TOP | SSD_TOP_LEFT | SSD_MIDDLE | SSD_BOTTOM_LEFT },
+ { 'G', SSD_TOP | SSD_TOP_LEFT | SSD_BOTTOM_LEFT | SSD_BOTTOM | SSD_BOTTOM_RIGHT },
+ { 'H', SSD_TOP_LEFT | SSD_TOP_RIGHT | SSD_MIDDLE |
+ SSD_BOTTOM_LEFT | SSD_BOTTOM_RIGHT },
+ { 'I', SSD_TOP_LEFT | SSD_BOTTOM_LEFT },
+ { 'J', SSD_TOP | SSD_TOP_RIGHT | SSD_BOTTOM_RIGHT | SSD_BOTTOM },
+ { 'K', SSD_TOP_LEFT | SSD_TOP_RIGHT | SSD_MIDDLE |
+ SSD_BOTTOM_LEFT | SSD_BOTTOM_RIGHT },
+ { 'L', SSD_TOP_LEFT | SSD_BOTTOM_LEFT | SSD_BOTTOM },
+ { 'O', SSD_TOP | SSD_TOP_LEFT | SSD_TOP_RIGHT |
+ SSD_BOTTOM_LEFT | SSD_BOTTOM_RIGHT | SSD_BOTTOM },
+ { 'P', SSD_TOP | SSD_TOP_LEFT | SSD_TOP_RIGHT | SSD_MIDDLE |
+ SSD_BOTTOM_LEFT },
+ { 'Q', SSD_TOP | SSD_TOP_LEFT | SSD_TOP_RIGHT |
+ SSD_BOTTOM_LEFT | SSD_BOTTOM_RIGHT | SSD_BOTTOM },
+ { 'R', SSD_TOP | SSD_TOP_LEFT | SSD_TOP_RIGHT | SSD_MIDDLE |
+ SSD_BOTTOM_LEFT | SSD_BOTTOM_RIGHT },
+ { 'S', SSD_TOP | SSD_TOP_LEFT | SSD_MIDDLE | SSD_BOTTOM_RIGHT | SSD_BOTTOM },
+ { 'T', SSD_TOP | SSD_TOP_LEFT | SSD_BOTTOM_LEFT },
+ { 'U', SSD_TOP_LEFT | SSD_BOTTOM_LEFT | SSD_BOTTOM | SSD_BOTTOM_RIGHT | SSD_TOP_RIGHT },
+ { 'V', SSD_TOP_LEFT | SSD_BOTTOM_LEFT | SSD_BOTTOM | SSD_BOTTOM_RIGHT | SSD_TOP_RIGHT },
+ { 'W', SSD_TOP_LEFT | SSD_BOTTOM_LEFT | SSD_BOTTOM | SSD_BOTTOM_RIGHT | SSD_TOP_RIGHT },
+ { 'Z', SSD_TOP | SSD_TOP_RIGHT | SSD_MIDDLE | SSD_BOTTOM_LEFT | SSD_BOTTOM },
+ { 'b', SSD_TOP_LEFT | SSD_MIDDLE | SSD_BOTTOM_LEFT | SSD_BOTTOM | SSD_BOTTOM_RIGHT },
+ { 'l', SSD_TOP_LEFT | SSD_BOTTOM_LEFT },
+ { 'o', SSD_MIDDLE | SSD_BOTTOM_LEFT | SSD_BOTTOM | SSD_BOTTOM_RIGHT },
+ { 't', SSD_TOP_LEFT | SSD_MIDDLE | SSD_BOTTOM_LEFT | SSD_BOTTOM },
+ { 'u', SSD_BOTTOM_LEFT | SSD_BOTTOM | SSD_BOTTOM_RIGHT },
+ { 'v', SSD_BOTTOM_LEFT | SSD_BOTTOM | SSD_BOTTOM_RIGHT },
+ { 'w', SSD_BOTTOM_LEFT | SSD_BOTTOM | SSD_BOTTOM_RIGHT },
+ { '-', SSD_MIDDLE },
+ { '_', SSD_BOTTOM },
+ { '.', SSD_DOT },
+};
+
+static u8 tm1628_get_char_ssd_map(char ch)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(tm1628_char_ssd_map); i++) {
+ if (tm1628_char_ssd_map[i].ch == ch)
+ return tm1628_char_ssd_map[i].segs;
+ }
+
+ return 0x0;
+}
+
+static int tm1628_display_apply_map(struct tm1628 *s,
+ struct tm1628_display *display, u8 map)
+{
+ struct tm1628_segment *segment;
+ int i;
+
+ for (i = 0; i < 8; i++) {
+ segment = &display->segments[i];
+ tm1628_set_led(s, segment->grid, segment->seg, map & BIT(i));
+ }
+
+ return 0;
+}
+
+static ssize_t text_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ struct tm1628 *s = dev_get_drvdata(dev);
+ size_t offset, len = count;
+ u8 map;
+ int i, ret;
+
+ if (len > 0 && buf[len - 1] == '\n')
+ len--;
+
+ for (i = 0, offset = 0; i < s->num_displays; i++) {
+ if (offset < len) {
+ map = tm1628_get_char_ssd_map(buf[offset]);
+ offset++;
+ } else
+ map = 0x0;
+
+ tm1628_display_apply_map(s, &s->displays[i], map);
+ }
+
+ ret = tm1628_set_address(s->spi, 0x0);
+ if (ret)
+ return ret;
+
+ ret = tm1628_write_data(s->spi, s->data, 14);
+ if (ret)
+ return ret;
+
+ return count;
+}
+
+static struct device_attribute tm1628_attr =
+ __ATTR_WO(text);
+
+static int tm1628_register_display(struct tm1628 *s,
+ struct fwnode_handle *node)
+{
+ struct device *dev = &s->spi->dev;
+ struct tm1628_display *display;
+ u32 *reg;
+ u32 grid, seg;
+ int i, j, ret, reg_count;
+
+ reg_count = fwnode_property_count_u32(node, "reg");
+ if (reg_count < 0)
+ return reg_count;
+
+ if (reg_count % 2) {
+ dev_warn(dev, "Ignoring extra cell in %s reg property\n",
+ fwnode_get_name(node));
+ reg_count--;
+ }
+
+ if (s->displays) {
+ dev_warn(dev, "Only one display supported\n");
+ return -EINVAL;
+ }
+
+ s->num_displays = reg_count >> 1;
+
+ reg = devm_kzalloc(dev, reg_count * sizeof(*reg), GFP_KERNEL);
+ if (!reg)
+ return -ENOMEM;
+
+ ret = fwnode_property_read_u32_array(node, "reg", reg, reg_count);
+ if (ret) {
+ dev_err(dev, "Reading %s reg property failed (%d)\n",
+ fwnode_get_name(node), ret);
+ return ret;
+ }
+
+ s->displays = devm_kzalloc(dev, s->num_displays * sizeof(*s->displays), GFP_KERNEL);
+ if (!s->displays)
+ return -ENOMEM;
+
+ for (i = 0; i < s->num_displays; i++) {
+ display = &s->displays[i];
+ grid = reg[i * 2];
+ seg = reg[i * 2 + 1];
+ if (grid == 0 && seg != 0) {
+ if (!tm1628_is_valid_seg(s, seg)) {
+ dev_warn(dev, "%s reg out of range\n", fwnode_get_name(node));
+ return -EINVAL;
+ }
+ grid = s->info->modes[s->mode_index].grid_mask;
+ for (j = 0; grid && j < 7; j++) {
+ display->segments[j].seg = seg;
+ display->segments[j].grid = __ffs(grid);
+ grid &= ~BIT(display->segments[j].grid);
+ }
+ } else if (grid != 0 && seg == 0) {
+ if (!tm1628_is_valid_grid(s, grid)) {
+ dev_warn(dev, "%s reg out of range\n", fwnode_get_name(node));
+ return -EINVAL;
+ }
+ seg = s->info->modes[s->mode_index].seg_mask;
+ for (j = 0; seg && j < 8; j++) {
+ display->segments[j].grid = grid;
+ display->segments[j].seg = __ffs(seg);
+ seg &= ~BIT(display->segments[j].seg);
+ }
+ }
+ }
+
+ devm_kfree(dev, reg);
+
+ device_create_file(dev, &tm1628_attr);
+
+ return 0;
+}
+
/* Work around __builtin_popcount() */
static u32 tm1628_grid_popcount(u8 grid_mask)
{
@@ -325,7 +545,7 @@ static int tm1628_spi_probe(struct spi_device *spi)
return ret;
}
- if (fwnode_property_count_u32(child, "reg") == 2) {
+ if (reg[0] != 0 && reg[1] != 0 && fwnode_property_count_u32(child, "reg") == 2) {
ret = tm1628_register_led(s, child, reg[0], reg[1], &s->leds[i++]);
if (ret && ret != -EINVAL) {
dev_err(&spi->dev, "Failed to register LED %s (%d)\n",
@@ -334,6 +554,14 @@ static int tm1628_spi_probe(struct spi_device *spi)
return ret;
}
s->num_leds++;
+ } else {
+ ret = tm1628_register_display(s, child);
+ if (ret) {
+ dev_err(&spi->dev, "Failed to register display %s (%d)\n",
+ fwnode_get_name(child), ret);
+ fwnode_handle_put(child);
+ return ret;
+ }
}
}
--
2.16.4