From: "Michal Vokáč" <michal.vokac@ysoft.com>
To: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: linux-fbdev@vger.kernel.org, "Michal Vokáč" <michal.vokac@ysoft.com>
Subject: [PATCH] video: ssd1307fb: Enable charge pump only on displays that actually have it
Date: Mon, 22 Mar 2021 19:11:05 +0100 [thread overview]
Message-ID: <1616436665-3046-1-git-send-email-michal.vokac@ysoft.com> (raw)
A note in the datasheet says:
"Patterns other than those given in the Command Table are prohibited to
enter the chip as a command; as unexpected results can occur."
So do not send the charge pump command to displays that do not support it.
Signed-off-by: Michal Vokáč <michal.vokac@ysoft.com>
---
drivers/video/fbdev/ssd1307fb.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c
index 1b0b2a096afa..54903ea2e3ac 100644
--- a/drivers/video/fbdev/ssd1307fb.c
+++ b/drivers/video/fbdev/ssd1307fb.c
@@ -497,14 +497,16 @@ static int ssd1307fb_init_regs(struct ssd1307fb_par *par)
return ret;
/* Turn on the DC-DC Charge Pump */
- ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CHARGE_PUMP);
- if (ret < 0)
- return ret;
+ if (par->device_info->need_chargepump) {
+ ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CHARGE_PUMP);
+ if (ret < 0)
+ return ret;
- ret = ssd1307fb_write_cmd(par->client,
- BIT(4) | (par->device_info->need_chargepump ? BIT(2) : 0));
- if (ret < 0)
- return ret;
+ ret = ssd1307fb_write_cmd(par->client,
+ BIT(4) | (par->device_info->need_chargepump ? BIT(2) : 0));
+ if (ret < 0)
+ return ret;
+ }
/* Set lookup table */
if (par->lookup_table_set) {
--
2.1.4
reply other threads:[~2021-03-22 18:18 UTC|newest]
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