Adding a check for UART Auto Flow Control feature and only
enabling the RTS override when it's not supported. RTS
override is not needed when Auto Flow Control is used and
they shouldn't be used together.
Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
---
drivers/acpi/acpi_lpss.c | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
index 1951b59..76cc698 100644
--- a/drivers/acpi/acpi_lpss.c
+++ b/drivers/acpi/acpi_lpss.c
@@ -83,18 +83,26 @@ struct lpss_private_data {
u32 prv_reg_ctx[LPSS_PRV_REG_COUNT];
};
+/* UART Component Parameter Register */
+#define LPSS_UART_CPR 0xF4
+#define LPSS_UART_CPR_AFCE BIT(4)
+
static void lpss_uart_setup(struct lpss_private_data *pdata)
{
unsigned int offset;
- u32 reg;
+ u32 val;
offset = pdata->dev_desc->prv_offset + LPSS_TX_INT;
- reg = readl(pdata->mmio_base + offset);
- writel(reg | LPSS_TX_INT_MASK, pdata->mmio_base + offset);
-
- offset = pdata->dev_desc->prv_offset + LPSS_GENERAL;
- reg = readl(pdata->mmio_base + offset);
- writel(reg | LPSS_GENERAL_UART_RTS_OVRD, pdata->mmio_base + offset);
+ val = readl(pdata->mmio_base + offset);
+ writel(val | LPSS_TX_INT_MASK, pdata->mmio_base + offset);
+
+ val = readl(pdata->mmio_base + LPSS_UART_CPR);
+ if (!(val & LPSS_UART_CPR_AFCE)) {
+ offset = pdata->dev_desc->prv_offset + LPSS_GENERAL;
+ val = readl(pdata->mmio_base + offset);
+ val |= LPSS_GENERAL_UART_RTS_OVRD;
+ writel(val, pdata->mmio_base + offset);
+ }
}
static void byt_i2c_setup(struct lpss_private_data *pdata)
--
2.1.0
--
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