]> git.karo-electronics.de Git - karo-tx-linux.git/blobdiff - drivers/tty/serial/sirfsoc_uart.c
Merge tag 'kvm-arm-for-4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git...
[karo-tx-linux.git] / drivers / tty / serial / sirfsoc_uart.c
index 653cdd5fb5088281049faa58c71566cd3a7aac5b..c6657de789977c9015899a2a2d581d68c81c349b 100644 (file)
@@ -413,7 +413,6 @@ sirfsoc_uart_pio_rx_chars(struct uart_port *port, unsigned int max_rx_count)
                        break;
        }
 
-       sirfport->rx_io_count += rx_count;
        port->icount.rx += rx_count;
 
        return rx_count;
@@ -600,7 +599,6 @@ static void sirfsoc_uart_start_next_rx_dma(struct uart_port *port)
        struct sirfsoc_uart_port *sirfport = to_sirfport(port);
        struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
        struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
-       sirfport->rx_io_count = 0;
        wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
                rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) &
                ~SIRFUART_IO_MODE);
@@ -632,31 +630,6 @@ static void sirfsoc_uart_start_next_rx_dma(struct uart_port *port)
                                sirfport->uart_reg->uart_type));
 }
 
-static void sirfsoc_uart_start_rx(struct uart_port *port)
-{
-       struct sirfsoc_uart_port *sirfport = to_sirfport(port);
-       struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
-       struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
-
-       sirfport->rx_io_count = 0;
-       wr_regl(port, ureg->sirfsoc_rx_fifo_op, SIRFUART_FIFO_RESET);
-       wr_regl(port, ureg->sirfsoc_rx_fifo_op, 0);
-       wr_regl(port, ureg->sirfsoc_rx_fifo_op, SIRFUART_FIFO_START);
-       if (sirfport->rx_dma_chan)
-               sirfsoc_uart_start_next_rx_dma(port);
-       else {
-               if (!sirfport->is_atlas7)
-                       wr_regl(port, ureg->sirfsoc_int_en_reg,
-                               rd_regl(port, ureg->sirfsoc_int_en_reg) |
-                               SIRFUART_RX_IO_INT_EN(uint_en,
-                                       sirfport->uart_reg->uart_type));
-               else
-                       wr_regl(port, ureg->sirfsoc_int_en_reg,
-                               SIRFUART_RX_IO_INT_EN(uint_en,
-                                       sirfport->uart_reg->uart_type));
-       }
-}
-
 static unsigned int
 sirfsoc_usp_calc_sample_div(unsigned long set_rate,
                unsigned long ioclk_rate, unsigned long *sample_reg)
@@ -850,7 +823,6 @@ static void sirfsoc_uart_set_termios(struct uart_port *port,
        rx_time_out = SIRFSOC_UART_RX_TIMEOUT(set_baud, 20000);
        rx_time_out = SIRFUART_RECV_TIMEOUT_VALUE(rx_time_out);
        txfifo_op_reg = rd_regl(port, ureg->sirfsoc_tx_fifo_op);
-       wr_regl(port, ureg->sirfsoc_rx_fifo_op, SIRFUART_FIFO_STOP);
        wr_regl(port, ureg->sirfsoc_tx_fifo_op,
                        (txfifo_op_reg & ~SIRFUART_FIFO_START));
        if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
@@ -886,9 +858,13 @@ static void sirfsoc_uart_set_termios(struct uart_port *port,
        else
                wr_regl(port, ureg->sirfsoc_tx_dma_io_ctrl, SIRFUART_IO_MODE);
        if (sirfport->rx_dma_chan)
-               wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl, SIRFUART_DMA_MODE);
+               wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
+                       rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) &
+                       ~SIRFUART_IO_MODE);
        else
-               wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl, SIRFUART_IO_MODE);
+               wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
+                       rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) |
+                       SIRFUART_IO_MODE);
        sirfport->rx_period_time = 20000000;
        /* Reset Rx/Tx FIFO Threshold level for proper baudrate */
        if (set_baud < 1000000)
@@ -902,7 +878,6 @@ static void sirfsoc_uart_set_termios(struct uart_port *port,
        txfifo_op_reg |= SIRFUART_FIFO_START;
        wr_regl(port, ureg->sirfsoc_tx_fifo_op, txfifo_op_reg);
        uart_update_timeout(port, termios->c_cflag, set_baud);
-       sirfsoc_uart_start_rx(port);
        wr_regl(port, ureg->sirfsoc_tx_rx_en, SIRFUART_TX_EN | SIRFUART_RX_EN);
        spin_unlock_irqrestore(&port->lock, flags);
 }
@@ -921,6 +896,7 @@ static int sirfsoc_uart_startup(struct uart_port *port)
 {
        struct sirfsoc_uart_port *sirfport      = to_sirfport(port);
        struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
+       struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
        unsigned int index                      = port->line;
        int ret;
        irq_modify_status(port->irq, IRQ_NOREQUEST, IRQ_NOAUTOEN);
@@ -958,9 +934,9 @@ static int sirfsoc_uart_startup(struct uart_port *port)
        wr_regl(port, ureg->sirfsoc_rx_fifo_ctrl, SIRFUART_FIFO_THD(port));
        if (sirfport->rx_dma_chan)
                wr_regl(port, ureg->sirfsoc_rx_fifo_level_chk,
-                       SIRFUART_RX_FIFO_CHK_SC(port->line, 0x4) |
-                       SIRFUART_RX_FIFO_CHK_LC(port->line, 0xe) |
-                       SIRFUART_RX_FIFO_CHK_HC(port->line, 0x1b));
+                       SIRFUART_RX_FIFO_CHK_SC(port->line, 0x1) |
+                       SIRFUART_RX_FIFO_CHK_LC(port->line, 0x2) |
+                       SIRFUART_RX_FIFO_CHK_HC(port->line, 0x4));
        if (sirfport->tx_dma_chan) {
                sirfport->tx_dma_state = TX_DMA_IDLE;
                wr_regl(port, ureg->sirfsoc_tx_fifo_level_chk,
@@ -981,16 +957,41 @@ static int sirfsoc_uart_startup(struct uart_port *port)
                        goto init_rx_err;
                }
        }
-       enable_irq(port->irq);
+       if (sirfport->uart_reg->uart_type == SIRF_REAL_UART &&
+               sirfport->rx_dma_chan)
+               wr_regl(port, ureg->sirfsoc_swh_dma_io,
+                       SIRFUART_CLEAR_RX_ADDR_EN);
+       if (sirfport->uart_reg->uart_type == SIRF_USP_UART &&
+                       sirfport->rx_dma_chan)
+               wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
+                       rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) |
+                       SIRFSOC_USP_FRADDR_CLR_EN);
        if (sirfport->rx_dma_chan && !sirfport->is_hrt_enabled) {
                sirfport->is_hrt_enabled = true;
                sirfport->rx_period_time = 20000000;
+               sirfport->rx_last_pos = -1;
+               sirfport->pio_fetch_cnt = 0;
                sirfport->rx_dma_items.xmit.tail =
                        sirfport->rx_dma_items.xmit.head = 0;
                hrtimer_start(&sirfport->hrt,
                        ns_to_ktime(sirfport->rx_period_time),
                        HRTIMER_MODE_REL);
        }
+       wr_regl(port, ureg->sirfsoc_rx_fifo_op, SIRFUART_FIFO_START);
+       if (sirfport->rx_dma_chan)
+               sirfsoc_uart_start_next_rx_dma(port);
+       else {
+               if (!sirfport->is_atlas7)
+                       wr_regl(port, ureg->sirfsoc_int_en_reg,
+                               rd_regl(port, ureg->sirfsoc_int_en_reg) |
+                               SIRFUART_RX_IO_INT_EN(uint_en,
+                                       sirfport->uart_reg->uart_type));
+               else
+                       wr_regl(port, ureg->sirfsoc_int_en_reg,
+                               SIRFUART_RX_IO_INT_EN(uint_en,
+                                       sirfport->uart_reg->uart_type));
+       }
+       enable_irq(port->irq);
 
        return 0;
 init_rx_err:
@@ -1003,6 +1004,9 @@ static void sirfsoc_uart_shutdown(struct uart_port *port)
 {
        struct sirfsoc_uart_port *sirfport = to_sirfport(port);
        struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
+       struct circ_buf *xmit;
+
+       xmit = &sirfport->rx_dma_items.xmit;
        if (!sirfport->is_atlas7)
                wr_regl(port, ureg->sirfsoc_int_en_reg, 0);
        else
@@ -1019,8 +1023,10 @@ static void sirfsoc_uart_shutdown(struct uart_port *port)
        if (sirfport->tx_dma_chan)
                sirfport->tx_dma_state = TX_DMA_IDLE;
        if (sirfport->rx_dma_chan && sirfport->is_hrt_enabled) {
-               while ((rd_regl(port, ureg->sirfsoc_rx_fifo_status) &
-                       SIRFUART_RX_FIFO_MASK) > 0)
+               while (((rd_regl(port, ureg->sirfsoc_rx_fifo_status) &
+                       SIRFUART_RX_FIFO_MASK) > sirfport->pio_fetch_cnt) &&
+                       !CIRC_CNT(xmit->head, xmit->tail,
+                       SIRFSOC_RX_DMA_BUF_SIZE))
                        ;
                sirfport->is_hrt_enabled = false;
                hrtimer_cancel(&sirfport->hrt);
@@ -1169,6 +1175,8 @@ static enum hrtimer_restart
        struct tty_struct *tty;
        struct sirfsoc_register *ureg;
        struct circ_buf *xmit;
+       struct sirfsoc_fifo_status *ufifo_st;
+       int max_pio_cnt;
 
        sirfport = container_of(hrt, struct sirfsoc_uart_port, hrt);
        port = &sirfport->port;
@@ -1176,9 +1184,16 @@ static enum hrtimer_restart
        tty = port->state->port.tty;
        ureg = &sirfport->uart_reg->uart_reg;
        xmit = &sirfport->rx_dma_items.xmit;
+       ufifo_st = &sirfport->uart_reg->fifo_status;
+
        dmaengine_tx_status(sirfport->rx_dma_chan,
-               sirfport->rx_dma_items.cookie, &tx_state);
-       xmit->head = SIRFSOC_RX_DMA_BUF_SIZE - tx_state.residue;
+                       sirfport->rx_dma_items.cookie, &tx_state);
+       if (SIRFSOC_RX_DMA_BUF_SIZE - tx_state.residue !=
+               sirfport->rx_last_pos) {
+               xmit->head = SIRFSOC_RX_DMA_BUF_SIZE - tx_state.residue;
+               sirfport->rx_last_pos = xmit->head;
+               sirfport->pio_fetch_cnt = 0;
+       }
        count = CIRC_CNT_TO_END(xmit->head, xmit->tail,
                        SIRFSOC_RX_DMA_BUF_SIZE);
        while (count > 0) {
@@ -1200,23 +1215,38 @@ static enum hrtimer_restart
         */
        if (!inserted && !count &&
                ((rd_regl(port, ureg->sirfsoc_rx_fifo_status) &
-               SIRFUART_RX_FIFO_MASK) > 0)) {
+               SIRFUART_RX_FIFO_MASK) > sirfport->pio_fetch_cnt)) {
+               dmaengine_pause(sirfport->rx_dma_chan);
                /* switch to pio mode */
                wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
                        rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) |
                        SIRFUART_IO_MODE);
-               while ((rd_regl(port, ureg->sirfsoc_rx_fifo_status) &
-                       SIRFUART_RX_FIFO_MASK) > 0) {
-                       if (sirfsoc_uart_pio_rx_chars(port, 16) > 0)
-                               tty_flip_buffer_push(tty->port);
+               /*
+                * UART controller SWH_DMA_IO register have CLEAR_RX_ADDR_EN
+                * When found changing I/O to DMA mode, it clears
+                * two low bits of read point;
+                * USP have similar FRADDR_CLR_EN bit in USP_RX_DMA_IO_CTRL.
+                * Fetch data out from rxfifo into DMA buffer in PIO mode,
+                * while switch back to DMA mode, the data fetched will override
+                * by DMA, as hardware have a strange behaviour:
+                * after switch back to DMA mode, check rxfifo status it will
+                * be the number PIO fetched, so record the fetched data count
+                * to avoid the repeated fetch
+                */
+               max_pio_cnt = 3;
+               while (!(rd_regl(port, ureg->sirfsoc_rx_fifo_status) &
+                       ufifo_st->ff_empty(port)) && max_pio_cnt--) {
+                       xmit->buf[xmit->head] =
+                               rd_regl(port, ureg->sirfsoc_rx_fifo_data);
+                       xmit->head = (xmit->head + 1) &
+                                       (SIRFSOC_RX_DMA_BUF_SIZE - 1);
+                       sirfport->pio_fetch_cnt++;
                }
-               wr_regl(port, ureg->sirfsoc_rx_fifo_op, SIRFUART_FIFO_RESET);
-               wr_regl(port, ureg->sirfsoc_rx_fifo_op, 0);
-               wr_regl(port, ureg->sirfsoc_rx_fifo_op, SIRFUART_FIFO_START);
                /* switch back to dma mode */
                wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
                        rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) &
                        ~SIRFUART_IO_MODE);
+               dmaengine_resume(sirfport->rx_dma_chan);
        }
 next_hrt:
        hrtimer_forward_now(hrt, ns_to_ktime(sirfport->rx_period_time));
@@ -1239,7 +1269,7 @@ static int sirfsoc_uart_probe(struct platform_device *pdev)
        struct resource *res;
        int ret;
        struct dma_slave_config slv_cfg = {
-               .src_maxburst = 2,
+               .src_maxburst = 1,
        };
        struct dma_slave_config tx_slv_cfg = {
                .dst_maxburst = 2,