tpm: cr50: Add a comment for cr50_priv

Add a comment for the private structure

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/tpm/cr50_i2c.c b/drivers/tpm/cr50_i2c.c
index b30f55b..c1d2d2f 100644
--- a/drivers/tpm/cr50_i2c.c
+++ b/drivers/tpm/cr50_i2c.c
@@ -34,6 +34,15 @@
 	CR50_MAX_BUF_SIZE = 63,
 };
 
+/**
+ * struct cr50_priv - Private driver data
+ *
+ * @ready_gpio: GPIO to use to check if the TPM is ready
+ * @irq: IRQ to use check if the TPM is ready (has priority over @ready_gpio)
+ * @locality: Currenttly claimed locality (-1 if none)
+ * @vendor: vendor: Vendor ID for TPM
+ * @use_irq: true to use @irq, false to use @ready if available
+ */
 struct cr50_priv {
 	struct gpio_desc ready_gpio;
 	struct irq irq;