Move the erratum handling mechanism from serial.c to driver file
and utilise the same func in driver file.
Acked-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
Signed-off-by: Govindraj.R <govindraj.raja@xxxxxx>
---
drivers/tty/serial/omap-serial.c | 58 ++++++++++++++++++++++++++++++++++---
1 files changed, 53 insertions(+), 5 deletions(-)
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 30bdd05..96fc860 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -52,6 +52,7 @@ static struct uart_omap_port *ui[OMAP_MAX_HSUART_PORTS];
static void uart_tx_dma_callback(int lch, u16 ch_status, void *data);
static void serial_omap_rx_timeout(unsigned long uart_no);
static int serial_omap_start_rxdma(struct uart_omap_port *up);
+static void omap_uart_mdr1_errataset(struct uart_omap_port *up, u8 mdr1);
static inline unsigned int serial_in(struct uart_omap_port *up, int offset)
{
@@ -805,7 +806,11 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
/* Protocol, Baud Rate, and Interrupt Settings */
- serial_out(up, UART_OMAP_MDR1, up->mdr1);
+ if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
+ omap_uart_mdr1_errataset(up, up->mdr1);
+ else
+ serial_out(up, UART_OMAP_MDR1, up->mdr1);
+
serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
up->efr = serial_in(up, UART_EFR);
@@ -830,7 +835,10 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
else
up->mdr1 = UART_OMAP_MDR1_16X_MODE;
- serial_out(up, UART_OMAP_MDR1, up->mdr1);
+ if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
+ omap_uart_mdr1_errataset(up, up->mdr1);
+ else
+ serial_out(up, UART_OMAP_MDR1, up->mdr1);
/* Hardware Flow Control Configuration */
@@ -1424,9 +1432,47 @@ static int serial_omap_remove(struct platform_device *dev)
return 0;
}
+/*
+ * Work Around for Errata i202 (3430 - 1.12, 3630 - 1.6)
+ * The access to uart register after MDR1 Access
+ * causes UART to corrupt data.
+ *
+ * Need a delay =
+ * 5 L4 clock cycles + 5 UART functional clock cycle (@48MHz = ~0.2uS)
+ * give 10 times as much
+ */
+static void omap_uart_mdr1_errataset(struct uart_omap_port *up, u8 mdr1)
+{
+ u8 timeout = 255;
+
+ serial_out(up, UART_OMAP_MDR1, mdr1);
+ udelay(2);
+ serial_out(up, UART_FCR, up->fcr | UART_FCR_CLEAR_XMIT |
+ UART_FCR_CLEAR_RCVR);
+ /*
+ * Wait for FIFO to empty: when empty, RX_FIFO_E bit is 0 and
+ * TX_FIFO_E bit is 1.
+ */
+ while (UART_LSR_THRE != (serial_in(up, UART_LSR) &
+ (UART_LSR_THRE | UART_LSR_DR))) {
+ timeout--;
+ if (!timeout) {
+ /* Should *never* happen. we warn and carry on */
+ dev_crit(&up->pdev->dev, "Errata i202: timedout %x\n",
+ serial_in(up, UART_LSR));
+ break;
+ }
+ udelay(1);
+ }
+}
+
static void omap_uart_restore_context(struct uart_omap_port *up)
{
- serial_out(up, UART_OMAP_MDR1, up->mdr1);
+ if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
+ omap_uart_mdr1_errataset(up, UART_OMAP_MDR1_DISABLE);
+ else
+ serial_out(up, UART_OMAP_MDR1, UART_OMAP_MDR1_DISABLE);
+
serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
serial_out(up, UART_EFR, UART_EFR_ECB);
serial_out(up, UART_LCR, 0x0); /* Operational mode */
@@ -1442,8 +1488,10 @@ static void omap_uart_restore_context(struct uart_omap_port *up)
serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
serial_out(up, UART_EFR, up->efr);
serial_out(up, UART_LCR, up->lcr);
- /* UART 16x mode */
- serial_out(up, UART_OMAP_MDR1, up->mdr1);
+ if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
+ omap_uart_mdr1_errataset(up, up->mdr1);
+ else
+ serial_out(up, UART_OMAP_MDR1, up->mdr1);
}
static int omap_serial_runtime_suspend(struct device *dev)
--
1.7.4.1
--
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