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path: root/drivers/tty/serial/imx.c
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Diffstat (limited to 'drivers/tty/serial/imx.c')
-rw-r--r--drivers/tty/serial/imx.c71
1 files changed, 52 insertions, 19 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 8f62a3cec23e..883f8a2f4ab5 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -49,6 +49,7 @@
#include <linux/of_device.h>
#include <linux/io.h>
#include <linux/dma-mapping.h>
+#include <linux/kgdb.h>
#include <asm/irq.h>
#include <linux/platform_data/serial-imx.h>
@@ -1507,44 +1508,73 @@ imx_verify_port(struct uart_port *port, struct serial_struct *ser)
}
#if defined(CONFIG_CONSOLE_POLL)
+
+#if defined(CONFIG_KGDB_FIQ)
+/*
+ * Prepare the UART to be used from kgdb's NMI support.
+ */
+static int imx_poll_init(struct uart_port *port)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+ unsigned long flags;
+ unsigned long temp;
+ int retval;
+
+ retval = clk_prepare_enable(sport->clk_ipg);
+ if (retval)
+ return retval;
+ retval = clk_prepare_enable(sport->clk_per);
+ if (retval)
+ clk_disable_unprepare(sport->clk_ipg);
+
+ imx_setup_ufcr(sport, 0);
+
+ spin_lock_irqsave(&sport->port.lock, flags);
+
+ temp = readl(sport->port.membase + UCR1);
+ if (is_imx1_uart(sport))
+ temp |= IMX1_UCR1_UARTCLKEN;
+ temp |= UCR1_UARTEN | UCR1_RRDYEN;
+ temp &= ~(UCR1_TXMPTYEN | UCR1_RTSDEN);
+ writel(temp, sport->port.membase + UCR1);
+
+ temp = readl(sport->port.membase + UCR2);
+ temp |= UCR2_RXEN;
+ writel(temp, sport->port.membase + UCR2);
+
+ spin_unlock_irqrestore(&sport->port.lock, flags);
+
+ /* register the FIQ with kgdb */
+ kgdb_register_fiq(sport->port.irq);
+
+ return 0;
+}
+#endif /* CONFIG_KGDB_FIQ */
+
static int imx_poll_get_char(struct uart_port *port)
{
- if (!(readl(port->membase + USR2) & USR2_RDR))
+ if (!(readl_relaxed(port->membase + USR2) & USR2_RDR))
return NO_POLL_CHAR;
- return readl(port->membase + URXD0) & URXD_RX_DATA;
+ return readl_relaxed(port->membase + URXD0) & URXD_RX_DATA;
}
static void imx_poll_put_char(struct uart_port *port, unsigned char c)
{
- struct imx_port_ucrs old_ucr;
unsigned int status;
- /* save control registers */
- imx_port_ucrs_save(port, &old_ucr);
-
- /* disable interrupts */
- writel(UCR1_UARTEN, port->membase + UCR1);
- writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
- port->membase + UCR2);
- writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
- port->membase + UCR3);
-
/* drain */
do {
- status = readl(port->membase + USR1);
+ status = readl_relaxed(port->membase + USR1);
} while (~status & USR1_TRDY);
/* write */
- writel(c, port->membase + URTX0);
+ writel_relaxed(c, port->membase + URTX0);
/* flush */
do {
- status = readl(port->membase + USR2);
+ status = readl_relaxed(port->membase + USR2);
} while (~status & USR2_TXDC);
-
- /* restore control registers */
- imx_port_ucrs_restore(port, &old_ucr);
}
#endif
@@ -1565,6 +1595,9 @@ static struct uart_ops imx_pops = {
.config_port = imx_config_port,
.verify_port = imx_verify_port,
#if defined(CONFIG_CONSOLE_POLL)
+#if defined(CONFIG_KGDB_FIQ)
+ .poll_init = imx_poll_init,
+#endif
.poll_get_char = imx_poll_get_char,
.poll_put_char = imx_poll_put_char,
#endif