diff options
| -rw-r--r-- | drivers/tty/serial/serial-tegra.c | 117 |
1 files changed, 86 insertions, 31 deletions
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c index d0fd41719e70..2f599515c133 100644 --- a/drivers/tty/serial/serial-tegra.c +++ b/drivers/tty/serial/serial-tegra.c @@ -139,6 +139,8 @@ struct tegra_uart_port { int n_adjustable_baud_rates; int required_rate; int configured_rate; + bool use_rx_pio; + bool use_tx_pio; }; static void tegra_uart_start_next_tx(struct tegra_uart_port *tup); @@ -567,7 +569,7 @@ static void tegra_uart_start_next_tx(struct tegra_uart_port *tup) if (!count) return; - if (count < TEGRA_UART_MIN_DMA) + if (tup->use_tx_pio || count < TEGRA_UART_MIN_DMA) tegra_uart_start_pio_tx(tup, count); else if (BYTES_TO_ALIGN(tail) > 0) tegra_uart_start_pio_tx(tup, BYTES_TO_ALIGN(tail)); @@ -800,6 +802,18 @@ static void tegra_uart_handle_modem_signal_change(struct uart_port *u) uart_handle_cts_change(&tup->uport, msr & UART_MSR_CTS); } +static void do_handle_rx_pio(struct tegra_uart_port *tup) +{ + struct tty_struct *tty = tty_port_tty_get(&tup->uport.state->port); + struct tty_port *port = &tup->uport.state->port; + + tegra_uart_handle_rx_pio(tup, port); + if (tty) { + tty_flip_buffer_push(port); + tty_kref_put(tty); + } +} + static irqreturn_t tegra_uart_isr(int irq, void *data) { struct tegra_uart_port *tup = data; @@ -813,7 +827,7 @@ static irqreturn_t tegra_uart_isr(int irq, void *data) while (1) { iir = tegra_uart_read(tup, UART_IIR); if (iir & UART_IIR_NO_INT) { - if (is_rx_int) { + if (!tup->use_rx_pio && is_rx_int) { tegra_uart_handle_rx_dma(tup); if (tup->rx_in_progress) { ier = tup->ier_shadow; @@ -841,7 +855,7 @@ static irqreturn_t tegra_uart_isr(int irq, void *data) case 4: /* End of data */ case 6: /* Rx timeout */ case 2: /* Receive */ - if (!is_rx_int) { + if (!tup->use_rx_pio && !is_rx_int) { is_rx_int = true; /* Disable Rx interrupts */ ier = tup->ier_shadow; @@ -851,6 +865,8 @@ static irqreturn_t tegra_uart_isr(int irq, void *data) UART_IER_RTOIE | TEGRA_UART_IER_EORD); tup->ier_shadow = ier; tegra_uart_write(tup, ier, UART_IER); + } else { + do_handle_rx_pio(tup); } break; @@ -869,6 +885,7 @@ static irqreturn_t tegra_uart_isr(int irq, void *data) static void tegra_uart_stop_rx(struct uart_port *u) { struct tegra_uart_port *tup = to_tegra_uport(u); + struct tty_port *port = &tup->uport.state->port; struct dma_tx_state state; unsigned long ier; @@ -886,9 +903,13 @@ static void tegra_uart_stop_rx(struct uart_port *u) tup->ier_shadow = ier; tegra_uart_write(tup, ier, UART_IER); tup->rx_in_progress = 0; - dmaengine_terminate_all(tup->rx_dma_chan); - dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state); - tegra_uart_rx_buffer_push(tup, state.residue); + if (tup->rx_dma_chan && !tup->use_rx_pio) { + dmaengine_terminate_all(tup->rx_dma_chan); + dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state); + tegra_uart_rx_buffer_push(tup, state.residue); + } else { + tegra_uart_handle_rx_pio(tup, port); + } } static void tegra_uart_hw_deinit(struct tegra_uart_port *tup) @@ -939,8 +960,10 @@ static void tegra_uart_hw_deinit(struct tegra_uart_port *tup) tup->rx_in_progress = 0; tup->tx_in_progress = 0; - tegra_uart_dma_channel_free(tup, true); - tegra_uart_dma_channel_free(tup, false); + if (!tup->use_rx_pio) + tegra_uart_dma_channel_free(tup, true); + if (!tup->use_tx_pio) + tegra_uart_dma_channel_free(tup, false); clk_disable_unprepare(tup->uart_clk); } @@ -985,10 +1008,14 @@ static int tegra_uart_hw_init(struct tegra_uart_port *tup) */ tup->fcr_shadow = UART_FCR_ENABLE_FIFO; - if (tup->cdata->max_dma_burst_bytes == 8) - tup->fcr_shadow |= UART_FCR_R_TRIG_10; - else - tup->fcr_shadow |= UART_FCR_R_TRIG_01; + if (tup->use_rx_pio) { + tup->fcr_shadow |= UART_FCR_R_TRIG_11; + } else { + if (tup->cdata->max_dma_burst_bytes == 8) + tup->fcr_shadow |= UART_FCR_R_TRIG_10; + else + tup->fcr_shadow |= UART_FCR_R_TRIG_01; + } tup->fcr_shadow |= TEGRA_UART_TX_TRIG_16B; tegra_uart_write(tup, tup->fcr_shadow, UART_FCR); @@ -1016,19 +1043,23 @@ static int tegra_uart_hw_init(struct tegra_uart_port *tup) * (115200, N, 8, 1) so that the receive DMA buffer may be * enqueued */ - tup->lcr_shadow = TEGRA_UART_DEFAULT_LSR; ret = tegra_set_baudrate(tup, TEGRA_UART_DEFAULT_BAUD); if (ret < 0) { dev_err(tup->uport.dev, "Failed to set baud rate\n"); return ret; } - tup->fcr_shadow |= UART_FCR_DMA_SELECT; - tegra_uart_write(tup, tup->fcr_shadow, UART_FCR); + if (!tup->use_rx_pio) { + tup->lcr_shadow = TEGRA_UART_DEFAULT_LSR; + tup->fcr_shadow |= UART_FCR_DMA_SELECT; + tegra_uart_write(tup, tup->fcr_shadow, UART_FCR); - ret = tegra_uart_start_rx_dma(tup); - if (ret < 0) { - dev_err(tup->uport.dev, "Not able to start Rx DMA\n"); - return ret; + ret = tegra_uart_start_rx_dma(tup); + if (ret < 0) { + dev_err(tup->uport.dev, "Not able to start Rx DMA\n"); + return ret; + } + } else { + tegra_uart_write(tup, tup->fcr_shadow, UART_FCR); } tup->rx_in_progress = 1; @@ -1050,7 +1081,12 @@ static int tegra_uart_hw_init(struct tegra_uart_port *tup) * both the EORD as well as RX_TIMEOUT - SW sees RX_TIMEOUT first * then the EORD. */ - tup->ier_shadow = UART_IER_RLSI | UART_IER_RTOIE | TEGRA_UART_IER_EORD; + if (!tup->use_rx_pio) + tup->ier_shadow = UART_IER_RLSI | UART_IER_RTOIE | + TEGRA_UART_IER_EORD; + else + tup->ier_shadow = UART_IER_RLSI | UART_IER_RTOIE | UART_IER_RDI; + tegra_uart_write(tup, tup->ier_shadow, UART_IER); return 0; } @@ -1145,16 +1181,22 @@ static int tegra_uart_startup(struct uart_port *u) struct tegra_uart_port *tup = to_tegra_uport(u); int ret; - ret = tegra_uart_dma_channel_allocate(tup, false); - if (ret < 0) { - dev_err(u->dev, "Tx Dma allocation failed, err = %d\n", ret); - return ret; + if (!tup->use_tx_pio) { + ret = tegra_uart_dma_channel_allocate(tup, false); + if (ret < 0) { + dev_err(u->dev, "Tx Dma allocation failed, err = %d\n", + ret); + return ret; + } } - ret = tegra_uart_dma_channel_allocate(tup, true); - if (ret < 0) { - dev_err(u->dev, "Rx Dma allocation failed, err = %d\n", ret); - goto fail_rx_dma; + if (!tup->use_rx_pio) { + ret = tegra_uart_dma_channel_allocate(tup, true); + if (ret < 0) { + dev_err(u->dev, "Rx Dma allocation failed, err = %d\n", + ret); + goto fail_rx_dma; + } } ret = tegra_uart_hw_init(tup); @@ -1172,9 +1214,11 @@ static int tegra_uart_startup(struct uart_port *u) return 0; fail_hw_init: - tegra_uart_dma_channel_free(tup, true); + if (!tup->use_rx_pio) + tegra_uart_dma_channel_free(tup, true); fail_rx_dma: - tegra_uart_dma_channel_free(tup, false); + if (!tup->use_tx_pio) + tegra_uart_dma_channel_free(tup, false); return ret; } @@ -1378,7 +1422,6 @@ static int tegra_uart_parse_dt(struct platform_device *pdev, int count; int n_entries; - port = of_alias_get_id(np, "serial"); if (port < 0) { dev_err(&pdev->dev, "failed to get alias id, errno %d\n", port); @@ -1388,6 +1431,18 @@ static int tegra_uart_parse_dt(struct platform_device *pdev, tup->enable_modem_interrupt = of_property_read_bool(np, "nvidia,enable-modem-interrupt"); + + index = of_property_match_string(np, "dma-names", "rx"); + if (index < 0) { + tup->use_rx_pio = true; + dev_info(&pdev->dev, "RX in PIO mode\n"); + } + index = of_property_match_string(np, "dma-names", "tx"); + if (index < 0) { + tup->use_tx_pio = true; + dev_info(&pdev->dev, "TX in PIO mode\n"); + } + n_entries = of_property_count_u32_elems(np, "nvidia,adjust-baud-rates"); if (n_entries > 0) { tup->n_adjustable_baud_rates = n_entries / 3; |