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authorGovindraj.R <govindraj.raja@ti.com>2011-11-07 19:00:33 +0530
committerKevin Hilman <khilman@ti.com>2011-12-14 16:05:22 -0800
commit94734749af794c080f6af6ac3ce8c1c13ee2dbbd (patch)
treefca071b796416579b42860980cd7324ac128d22e /drivers/tty
parentec3bebc6ec64aac23500e6b8ef5c0aaaeda735cf (diff)
downloadop-kernel-dev-94734749af794c080f6af6ac3ce8c1c13ee2dbbd.zip
op-kernel-dev-94734749af794c080f6af6ac3ce8c1c13ee2dbbd.tar.gz
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>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/omap-serial.c68
1 files changed, 64 insertions, 4 deletions
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 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;
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