serial: stm32: add fifo support

This patch adds fifo mode support for rx and tx.

A fifo configuration is set in each port structure.
Add has_fifo flag to usart configuration to use fifo only when possible.

Signed-off-by: Gerald Baeza <gerald.baeza@st.com>
Signed-off-by: Bich Hemon <bich.hemon@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 9c43573..72c0ec1 100644 (file)
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -468,6 +468,8 @@ static int stm32_startup(struct uart_port *port)
        }
 
        val = USART_CR1_RXNEIE | USART_CR1_TE | USART_CR1_RE;
+       if (stm32_port->fifoen)
+               val |= USART_CR1_FIFOEN;
        stm32_set_bits(port, ofs->cr1, val);
 
        return 0;
@@ -482,6 +484,8 @@ static void stm32_shutdown(struct uart_port *port)
 
        val = USART_CR1_TXEIE | USART_CR1_RXNEIE | USART_CR1_TE | USART_CR1_RE;
        val |= BIT(cfg->uart_enable_bit);
+       if (stm32_port->fifoen)
+               val |= USART_CR1_FIFOEN;
        stm32_clr_bits(port, ofs->cr1, val);
 
        dev_pm_clear_wake_irq(port->dev);
@@ -512,6 +516,8 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios,
 
        cr1 = USART_CR1_TE | USART_CR1_RE | USART_CR1_RXNEIE;
        cr1 |= BIT(cfg->uart_enable_bit);
+       if (stm32_port->fifoen)
+               cr1 |= USART_CR1_FIFOEN;
        cr2 = 0;
        cr3 = 0;
 
@@ -676,6 +682,7 @@ static int stm32_init_port(struct stm32_port *stm32port,
        port->dev       = &pdev->dev;
        port->irq       = platform_get_irq(pdev, 0);
        stm32port->wakeirq = platform_get_irq(pdev, 1);
+       stm32port->fifoen = stm32port->info->cfg.has_fifo;
 
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        port->membase = devm_ioremap_resource(&pdev->dev, res);

diff --git a/drivers/tty/serial/stm32-usart.h b/drivers/tty/serial/stm32-usart.h
index 5984a66..ffc0c52 100644 (file)
--- a/drivers/tty/serial/stm32-usart.h
+++ b/drivers/tty/serial/stm32-usart.h
@@ -26,6 +26,7 @@ struct stm32_usart_config {
        u8 uart_enable_bit; /* USART_CR1_UE */
        bool has_7bits_data;
        bool has_wakeup;
+       bool has_fifo;
 };
 
 struct stm32_usart_info {
@@ -94,6 +95,7 @@ struct stm32_usart_info stm32h7_info = {
                .uart_enable_bit = 0,
                .has_7bits_data = true,
                .has_wakeup = true,
+               .has_fifo = true,
        }
 };
 
@@ -159,6 +161,7 @@ struct stm32_usart_info stm32h7_info = {
 #define USART_CR1_EOBIE                BIT(27)         /* F7 */
 #define USART_CR1_M1           BIT(28)         /* F7 */
 #define USART_CR1_IE_MASK      (GENMASK(8, 4) | BIT(14) | BIT(26) | BIT(27))
+#define USART_CR1_FIFOEN       BIT(29)         /* H7 */
 
 /* USART_CR2 */
 #define USART_CR2_ADD_MASK     GENMASK(3, 0)   /* F4 */
@@ -253,6 +256,7 @@ struct stm32_port {
        int last_res;
        bool tx_dma_busy;        /* dma tx busy               */
        bool hw_flow_control;
+       bool fifoen;
        int wakeirq;
 };