Introduce support for early debugging. This relies on the previous stage bootloader to initialise the UART clocks, when running with U-Boot as the primary bootloader this feature doesn't work. It will require a way to configure the clocks before the driver model is available.
Signed-off-by: Caleb Connolly caleb.connolly@linaro.org --- drivers/serial/Kconfig | 8 ++++++++ drivers/serial/serial_msm.c | 32 ++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+)
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index 26460c4e0cab..fbd351a47859 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -319,6 +319,14 @@ config DEBUG_UART_S5P will need to provide parameters to make this work. The driver will be available until the real driver-model serial is running.
+config DEBUG_UART_MSM + bool "Qualcomm QUP UART debug" + depends on ARCH_SNAPDRAGON + help + Select this to enable a debug UART using the serial_msm driver. You + will need to provide parameters to make this work. The driver will + be available until the real driver-model serial is running. + config DEBUG_UART_MSM_GENI bool "Qualcomm snapdragon" depends on ARCH_SNAPDRAGON diff --git a/drivers/serial/serial_msm.c b/drivers/serial/serial_msm.c index a22623c316ed..19a5a3a788f7 100644 --- a/drivers/serial/serial_msm.c +++ b/drivers/serial/serial_msm.c @@ -253,3 +253,35 @@ U_BOOT_DRIVER(serial_msm) = { .probe = msm_serial_probe, .ops = &msm_serial_ops, }; + +#ifdef CONFIG_DEBUG_UART_MSM + +static struct msm_serial_data init_serial_data = { + .base = CONFIG_VAL(DEBUG_UART_BASE), + .clk_bit_rate = UART_DM_CLK_RX_TX_BIT_RATE, +}; + +#include <debug_uart.h> + +static inline void _debug_uart_init(void) +{ + uart_dm_init(&init_serial_data); +} + +static inline void _debug_uart_putc(int ch) +{ + struct msm_serial_data *priv = &init_serial_data; + + while (!(readl(priv->base + UARTDM_SR) & UARTDM_SR_TX_EMPTY) && + !(readl(priv->base + UARTDM_ISR) & UARTDM_ISR_TX_READY)) + ; + + writel(UARTDM_CR_CMD_RESET_TX_READY, priv->base + UARTDM_CR); + + writel(1, priv->base + UARTDM_NCF_TX); + writel(ch, priv->base + UARTDM_TF); +} + +DEBUG_UART_FUNCS + +#endif