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-rw-r--r--drivers/gpu/drm/bridge/ti-sn65dsi86.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
index c2bdc7e57ac7..f72675766e01 100644
--- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
+++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
@@ -35,6 +35,7 @@
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
+#define SN_DEVICE_ID_REGS 0x00 /* up to 0x07 */
#define SN_DEVICE_REV_REG 0x08
#define SN_DPPLL_SRC_REG 0x0A
#define DPPLL_CLK_SRC_DSICLK BIT(0)
@@ -1898,6 +1899,7 @@ static int ti_sn65dsi86_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct ti_sn65dsi86 *pdata;
+ u8 id_buf[8];
int ret;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
@@ -1941,6 +1943,16 @@ static int ti_sn65dsi86_probe(struct i2c_client *client)
if (ret)
return ret;
+ pm_runtime_get_sync(dev);
+ ret = regmap_bulk_read(pdata->regmap, SN_DEVICE_ID_REGS, id_buf, ARRAY_SIZE(id_buf));
+ pm_runtime_put_autosuspend(dev);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to read device id\n");
+
+ /* The ID string is stored backwards */
+ if (strncmp(id_buf, "68ISD ", ARRAY_SIZE(id_buf)))
+ return dev_err_probe(dev, -EOPNOTSUPP, "unsupported device id\n");
+
/*
* Break ourselves up into a collection of aux devices. The only real
* motiviation here is to solve the chicken-and-egg problem of probe