diff options
Diffstat (limited to 'drivers/tty/serial/omap-serial.c')
| -rw-r--r-- | drivers/tty/serial/omap-serial.c | 68 |
1 files changed, 64 insertions, 4 deletions
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index ea4c24aa8c8..764ac779569 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; |