ARM: OMAP2+: UART: Move errata handling from serial.c to omap-serial
Move the errata handling mechanism from serial.c to omap-serial file
and utilise the same func in driver file.
Errata i202, i291 are moved to be handled with omap-serial
Moving the errata macro from serial.c file to driver header file
as from on errata will be handled in driver file itself.
Corrected errata id from chapter reference 2.15 to errata id i291.
Removed errata and dma_enabled fields from omap_uart_state struct
as they are no more needed with errata handling done within omap-serial.
Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Kevin Hilman <khilman@ti.com>
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index ea4c24a..764ac77 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -51,6 +51,7 @@
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 @@
/* 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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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;