From: Heikki Krogerus <[email protected]> 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 <[email protected]> Signed-off-by: Rafael J. Wysocki <[email protected]> (cherry picked from commit 1f47a77c4e4951f141bf20fe7f7c5d9438ea1663) Signed-off-by: Ng, Wei Tee <[email protected]> --- 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 8c2bae9..7e038be 100644 --- a/drivers/acpi/acpi_lpss.c +++ b/drivers/acpi/acpi_lpss.c @@ -67,18 +67,26 @@ struct lpss_private_data { const struct lpss_device_desc *dev_desc; }; +/* 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 struct lpss_device_desc lpt_dev_desc = { -- 1.7.9.5 -- _______________________________________________ linux-yocto mailing list [email protected] https://lists.yoctoproject.org/listinfo/linux-yocto
