1 files changed, 64 insertions, 4 deletions

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index ea4c24aa8c87..764ac7795694 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -51,6 +51,7 @@ 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 serial_omap_mdr1_errataset(struct uart_omap_port *up, u8 mdr1);
 
 static inline unsigned int serial_in(struct uart_omap_port *up, int offset)
 {
@@ -808,7 +809,11 @@ 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)
+                serial_omap_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);
@@ -833,7 +838,10 @@ 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)
+                serial_omap_mdr1_errataset(up, up->mdr1);
+        else
+                serial_out(up, UART_OMAP_MDR1, up->mdr1);
 
         /* Hardware Flow Control Configuration */
 
@@ -1362,6 +1370,7 @@ static int serial_omap_probe(struct platform_device *pdev)
         up->port.flags = omap_up_info->flags;
         up->port.uartclk = omap_up_info->uartclk;
         up->uart_dma.uart_base = mem->start;
+        up->errata = omap_up_info->errata;
 
         if (omap_up_info->dma_enabled) {
                 up->uart_dma.uart_dma_tx = dma_tx->start;
@@ -1415,9 +1424,47 @@ static int serial_omap_remove(struct platform_device *dev)
         return 0;
 }
 
+/*
+ * Work Around for Errata i202 (2430, 3430, 3630, 4430 and 4460)
+ * 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 serial_omap_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 serial_omap_restore_context(struct uart_omap_port *up)
 {
-        serial_out(up, UART_OMAP_MDR1, UART_OMAP_MDR1_DISABLE);
+        if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
+                serial_omap_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 */
@@ -1434,7 +1481,10 @@ static void serial_omap_restore_context(struct uart_omap_port *up)
         serial_out(up, UART_OMAP_SCR, up->scr);
         serial_out(up, UART_EFR, up->efr);
         serial_out(up, UART_LCR, up->lcr);
-        serial_out(up, UART_OMAP_MDR1, up->mdr1);
+        if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
+                serial_omap_mdr1_errataset(up, up->mdr1);
+        else
+                serial_out(up, UART_OMAP_MDR1, up->mdr1);
 }
 
 #ifdef CONFIG_PM_RUNTIME
@@ -1449,6 +1499,11 @@ static int serial_omap_runtime_suspend(struct device *dev)
         if (pdata->get_context_loss_count)
                 up->context_loss_cnt = pdata->get_context_loss_count(dev);
 
+        /* Errata i291 */
+        if (up->use_dma && pdata->set_forceidle &&
+                        (up->errata & UART_ERRATA_i291_DMA_FORCEIDLE))
+                pdata->set_forceidle(up->pdev);
+
         return 0;
 }
 
@@ -1464,6 +1519,11 @@ static int serial_omap_runtime_resume(struct device *dev)
                         if (up->context_loss_cnt != loss_cnt)
                                 serial_omap_restore_context(up);
                 }
+
+                /* Errata i291 */
+                if (up->use_dma && pdata->set_noidle &&
+                                (up->errata & UART_ERRATA_i291_DMA_FORCEIDLE))
+                        pdata->set_noidle(up->pdev);
         }
 
         return 0;