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1788cf6a91
Switch from struct circ_buf to proper kfifo. kfifo provides much better API, esp. when wrap-around of the buffer needs to be taken into account. Look at pl011_dma_tx_refill() or cpm_uart_tx_pump() changes for example. Kfifo API can also fill in scatter-gather DMA structures, so it easier for that use case too. Look at lpuart_dma_tx() for example. Note that not all drivers can be converted to that (like atmel_serial), they handle DMA specially. Note that usb-serial uses kfifo for TX for ages. omap needed a bit more care as it needs to put a char into FIFO to start the DMA transfer when OMAP_DMA_TX_KICK is set. In that case, we have to do kfifo_dma_out_prepare twice: once to find out the tx_size (to find out if it is worths to do DMA at all -- size >= 4), the second time for the actual transfer. All traces of circ_buf are removed from serial_core.h (and its struct uart_state). Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Cc: Al Cooper <alcooperx@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Cc: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com> Cc: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Nicolas Ferre <nicolas.ferre@microchip.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Claudiu Beznea <claudiu.beznea@tuxon.dev> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: Maciej W. Rozycki <macro@orcam.me.uk> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: Neil Armstrong <neil.armstrong@linaro.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Jerome Brunet <jbrunet@baylibre.com> Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Cc: Taichi Sugaya <sugaya.taichi@socionext.com> Cc: Takao Orito <orito.takao@socionext.com> Cc: Bjorn Andersson <andersson@kernel.org> Cc: Konrad Dybcio <konrad.dybcio@linaro.org> Cc: Pali Rohár <pali@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Cc: Alim Akhtar <alim.akhtar@samsung.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Orson Zhai <orsonzhai@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: Patrice Chotard <patrice.chotard@foss.st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: David S. Miller <davem@davemloft.net> Cc: Hammer Hsieh <hammerh0314@gmail.com> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@kernel.org> Cc: Michal Simek <michal.simek@amd.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Christian König <christian.koenig@amd.com> Link: https://lore.kernel.org/r/20240405060826.2521-13-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
497 lines
12 KiB
C
497 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* timbuart.c timberdale FPGA UART driver
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* Copyright (c) 2009 Intel Corporation
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*/
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/* Supports:
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* Timberdale FPGA UART
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*/
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#include <linux/pci.h>
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#include <linux/interrupt.h>
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#include <linux/serial_core.h>
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#include <linux/tty.h>
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#include <linux/tty_flip.h>
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#include <linux/kernel.h>
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#include <linux/platform_device.h>
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#include <linux/ioport.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include "timbuart.h"
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struct timbuart_port {
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struct uart_port port;
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struct tasklet_struct tasklet;
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int usedma;
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u32 last_ier;
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struct platform_device *dev;
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};
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static int baudrates[] = {9600, 19200, 38400, 57600, 115200, 230400, 460800,
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921600, 1843200, 3250000};
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static void timbuart_mctrl_check(struct uart_port *port, u32 isr, u32 *ier);
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static irqreturn_t timbuart_handleinterrupt(int irq, void *devid);
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static void timbuart_stop_rx(struct uart_port *port)
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{
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/* spin lock held by upper layer, disable all RX interrupts */
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u32 ier = ioread32(port->membase + TIMBUART_IER) & ~RXFLAGS;
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iowrite32(ier, port->membase + TIMBUART_IER);
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}
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static void timbuart_stop_tx(struct uart_port *port)
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{
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/* spinlock held by upper layer, disable TX interrupt */
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u32 ier = ioread32(port->membase + TIMBUART_IER) & ~TXBAE;
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iowrite32(ier, port->membase + TIMBUART_IER);
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}
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static void timbuart_start_tx(struct uart_port *port)
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{
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struct timbuart_port *uart =
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container_of(port, struct timbuart_port, port);
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/* do not transfer anything here -> fire off the tasklet */
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tasklet_schedule(&uart->tasklet);
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}
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static unsigned int timbuart_tx_empty(struct uart_port *port)
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{
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u32 isr = ioread32(port->membase + TIMBUART_ISR);
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return (isr & TXBE) ? TIOCSER_TEMT : 0;
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}
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static void timbuart_flush_buffer(struct uart_port *port)
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{
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if (!timbuart_tx_empty(port)) {
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u8 ctl = ioread8(port->membase + TIMBUART_CTRL) |
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TIMBUART_CTRL_FLSHTX;
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iowrite8(ctl, port->membase + TIMBUART_CTRL);
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iowrite32(TXBF, port->membase + TIMBUART_ISR);
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}
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}
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static void timbuart_rx_chars(struct uart_port *port)
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{
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struct tty_port *tport = &port->state->port;
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while (ioread32(port->membase + TIMBUART_ISR) & RXDP) {
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u8 ch = ioread8(port->membase + TIMBUART_RXFIFO);
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port->icount.rx++;
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tty_insert_flip_char(tport, ch, TTY_NORMAL);
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}
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tty_flip_buffer_push(tport);
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dev_dbg(port->dev, "%s - total read %d bytes\n",
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__func__, port->icount.rx);
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}
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static void timbuart_tx_chars(struct uart_port *port)
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{
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unsigned char ch;
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while (!(ioread32(port->membase + TIMBUART_ISR) & TXBF) &&
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uart_fifo_get(port, &ch))
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iowrite8(ch, port->membase + TIMBUART_TXFIFO);
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dev_dbg(port->dev,
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"%s - total written %d bytes, CTL: %x, RTS: %x, baud: %x\n",
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__func__,
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port->icount.tx,
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ioread8(port->membase + TIMBUART_CTRL),
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port->mctrl & TIOCM_RTS,
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ioread8(port->membase + TIMBUART_BAUDRATE));
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}
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static void timbuart_handle_tx_port(struct uart_port *port, u32 isr, u32 *ier)
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{
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struct timbuart_port *uart =
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container_of(port, struct timbuart_port, port);
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struct tty_port *tport = &port->state->port;
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if (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(port))
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return;
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if (port->x_char)
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return;
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if (isr & TXFLAGS) {
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timbuart_tx_chars(port);
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/* clear all TX interrupts */
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iowrite32(TXFLAGS, port->membase + TIMBUART_ISR);
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if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
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uart_write_wakeup(port);
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} else
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/* Re-enable any tx interrupt */
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*ier |= uart->last_ier & TXFLAGS;
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/* enable interrupts if there are chars in the transmit buffer,
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* Or if we delivered some bytes and want the almost empty interrupt
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* we wake up the upper layer later when we got the interrupt
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* to give it some time to go out...
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*/
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if (!kfifo_is_empty(&tport->xmit_fifo))
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*ier |= TXBAE;
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dev_dbg(port->dev, "%s - leaving\n", __func__);
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}
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static void timbuart_handle_rx_port(struct uart_port *port, u32 isr, u32 *ier)
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{
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if (isr & RXFLAGS) {
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/* Some RX status is set */
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if (isr & RXBF) {
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u8 ctl = ioread8(port->membase + TIMBUART_CTRL) |
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TIMBUART_CTRL_FLSHRX;
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iowrite8(ctl, port->membase + TIMBUART_CTRL);
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port->icount.overrun++;
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} else if (isr & (RXDP))
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timbuart_rx_chars(port);
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/* ack all RX interrupts */
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iowrite32(RXFLAGS, port->membase + TIMBUART_ISR);
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}
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/* always have the RX interrupts enabled */
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*ier |= RXBAF | RXBF | RXTT;
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dev_dbg(port->dev, "%s - leaving\n", __func__);
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}
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static void timbuart_tasklet(struct tasklet_struct *t)
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{
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struct timbuart_port *uart = from_tasklet(uart, t, tasklet);
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u32 isr, ier = 0;
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uart_port_lock(&uart->port);
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isr = ioread32(uart->port.membase + TIMBUART_ISR);
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dev_dbg(uart->port.dev, "%s ISR: %x\n", __func__, isr);
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if (!uart->usedma)
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timbuart_handle_tx_port(&uart->port, isr, &ier);
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timbuart_mctrl_check(&uart->port, isr, &ier);
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if (!uart->usedma)
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timbuart_handle_rx_port(&uart->port, isr, &ier);
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iowrite32(ier, uart->port.membase + TIMBUART_IER);
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uart_port_unlock(&uart->port);
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dev_dbg(uart->port.dev, "%s leaving\n", __func__);
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}
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static unsigned int timbuart_get_mctrl(struct uart_port *port)
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{
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u8 cts = ioread8(port->membase + TIMBUART_CTRL);
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dev_dbg(port->dev, "%s - cts %x\n", __func__, cts);
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if (cts & TIMBUART_CTRL_CTS)
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return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
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else
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return TIOCM_DSR | TIOCM_CAR;
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}
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static void timbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
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{
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dev_dbg(port->dev, "%s - %x\n", __func__, mctrl);
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if (mctrl & TIOCM_RTS)
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iowrite8(TIMBUART_CTRL_RTS, port->membase + TIMBUART_CTRL);
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else
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iowrite8(0, port->membase + TIMBUART_CTRL);
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}
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static void timbuart_mctrl_check(struct uart_port *port, u32 isr, u32 *ier)
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{
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unsigned int cts;
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if (isr & CTS_DELTA) {
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/* ack */
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iowrite32(CTS_DELTA, port->membase + TIMBUART_ISR);
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cts = timbuart_get_mctrl(port);
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uart_handle_cts_change(port, cts & TIOCM_CTS);
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wake_up_interruptible(&port->state->port.delta_msr_wait);
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}
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*ier |= CTS_DELTA;
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}
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static void timbuart_break_ctl(struct uart_port *port, int ctl)
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{
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/* N/A */
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}
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static int timbuart_startup(struct uart_port *port)
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{
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struct timbuart_port *uart =
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container_of(port, struct timbuart_port, port);
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dev_dbg(port->dev, "%s\n", __func__);
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iowrite8(TIMBUART_CTRL_FLSHRX, port->membase + TIMBUART_CTRL);
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iowrite32(0x1ff, port->membase + TIMBUART_ISR);
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/* Enable all but TX interrupts */
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iowrite32(RXBAF | RXBF | RXTT | CTS_DELTA,
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port->membase + TIMBUART_IER);
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return request_irq(port->irq, timbuart_handleinterrupt, IRQF_SHARED,
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"timb-uart", uart);
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}
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static void timbuart_shutdown(struct uart_port *port)
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{
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struct timbuart_port *uart =
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container_of(port, struct timbuart_port, port);
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dev_dbg(port->dev, "%s\n", __func__);
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free_irq(port->irq, uart);
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iowrite32(0, port->membase + TIMBUART_IER);
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timbuart_flush_buffer(port);
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}
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static int get_bindex(int baud)
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{
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int i;
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for (i = 0; i < ARRAY_SIZE(baudrates); i++)
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if (baud <= baudrates[i])
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return i;
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return -1;
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}
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static void timbuart_set_termios(struct uart_port *port,
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struct ktermios *termios,
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const struct ktermios *old)
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{
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unsigned int baud;
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short bindex;
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unsigned long flags;
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baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
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bindex = get_bindex(baud);
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dev_dbg(port->dev, "%s - bindex %d\n", __func__, bindex);
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if (bindex < 0)
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bindex = 0;
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baud = baudrates[bindex];
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/* The serial layer calls into this once with old = NULL when setting
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up initially */
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if (old)
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tty_termios_copy_hw(termios, old);
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tty_termios_encode_baud_rate(termios, baud, baud);
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uart_port_lock_irqsave(port, &flags);
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iowrite8((u8)bindex, port->membase + TIMBUART_BAUDRATE);
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uart_update_timeout(port, termios->c_cflag, baud);
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uart_port_unlock_irqrestore(port, flags);
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}
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static const char *timbuart_type(struct uart_port *port)
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{
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return port->type == PORT_UNKNOWN ? "timbuart" : NULL;
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}
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/* We do not request/release mappings of the registers here,
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* currently it's done in the proble function.
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*/
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static void timbuart_release_port(struct uart_port *port)
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{
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struct platform_device *pdev = to_platform_device(port->dev);
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int size =
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resource_size(platform_get_resource(pdev, IORESOURCE_MEM, 0));
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if (port->flags & UPF_IOREMAP) {
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iounmap(port->membase);
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port->membase = NULL;
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}
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release_mem_region(port->mapbase, size);
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}
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static int timbuart_request_port(struct uart_port *port)
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{
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struct platform_device *pdev = to_platform_device(port->dev);
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int size =
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resource_size(platform_get_resource(pdev, IORESOURCE_MEM, 0));
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if (!request_mem_region(port->mapbase, size, "timb-uart"))
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return -EBUSY;
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if (port->flags & UPF_IOREMAP) {
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port->membase = ioremap(port->mapbase, size);
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if (port->membase == NULL) {
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release_mem_region(port->mapbase, size);
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return -ENOMEM;
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}
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}
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return 0;
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}
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static irqreturn_t timbuart_handleinterrupt(int irq, void *devid)
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{
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struct timbuart_port *uart = (struct timbuart_port *)devid;
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if (ioread8(uart->port.membase + TIMBUART_IPR)) {
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uart->last_ier = ioread32(uart->port.membase + TIMBUART_IER);
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/* disable interrupts, the tasklet enables them again */
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iowrite32(0, uart->port.membase + TIMBUART_IER);
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/* fire off bottom half */
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tasklet_schedule(&uart->tasklet);
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return IRQ_HANDLED;
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} else
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return IRQ_NONE;
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}
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/*
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* Configure/autoconfigure the port.
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*/
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static void timbuart_config_port(struct uart_port *port, int flags)
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{
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if (flags & UART_CONFIG_TYPE) {
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port->type = PORT_TIMBUART;
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timbuart_request_port(port);
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}
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}
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static int timbuart_verify_port(struct uart_port *port,
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struct serial_struct *ser)
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{
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/* we don't want the core code to modify any port params */
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return -EINVAL;
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}
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static const struct uart_ops timbuart_ops = {
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.tx_empty = timbuart_tx_empty,
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.set_mctrl = timbuart_set_mctrl,
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.get_mctrl = timbuart_get_mctrl,
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.stop_tx = timbuart_stop_tx,
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.start_tx = timbuart_start_tx,
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.flush_buffer = timbuart_flush_buffer,
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.stop_rx = timbuart_stop_rx,
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.break_ctl = timbuart_break_ctl,
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.startup = timbuart_startup,
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.shutdown = timbuart_shutdown,
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.set_termios = timbuart_set_termios,
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.type = timbuart_type,
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.release_port = timbuart_release_port,
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.request_port = timbuart_request_port,
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.config_port = timbuart_config_port,
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.verify_port = timbuart_verify_port
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};
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static struct uart_driver timbuart_driver = {
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.owner = THIS_MODULE,
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.driver_name = "timberdale_uart",
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.dev_name = "ttyTU",
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.major = TIMBUART_MAJOR,
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.minor = TIMBUART_MINOR,
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.nr = 1
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};
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static int timbuart_probe(struct platform_device *dev)
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{
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int err, irq;
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struct timbuart_port *uart;
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struct resource *iomem;
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dev_dbg(&dev->dev, "%s\n", __func__);
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uart = kzalloc(sizeof(*uart), GFP_KERNEL);
|
|
if (!uart) {
|
|
err = -EINVAL;
|
|
goto err_mem;
|
|
}
|
|
|
|
uart->usedma = 0;
|
|
|
|
uart->port.uartclk = 3250000 * 16;
|
|
uart->port.fifosize = TIMBUART_FIFO_SIZE;
|
|
uart->port.regshift = 2;
|
|
uart->port.iotype = UPIO_MEM;
|
|
uart->port.ops = &timbuart_ops;
|
|
uart->port.irq = 0;
|
|
uart->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP;
|
|
uart->port.line = 0;
|
|
uart->port.dev = &dev->dev;
|
|
|
|
iomem = platform_get_resource(dev, IORESOURCE_MEM, 0);
|
|
if (!iomem) {
|
|
err = -ENOMEM;
|
|
goto err_register;
|
|
}
|
|
uart->port.mapbase = iomem->start;
|
|
uart->port.membase = NULL;
|
|
|
|
irq = platform_get_irq(dev, 0);
|
|
if (irq < 0) {
|
|
err = -EINVAL;
|
|
goto err_register;
|
|
}
|
|
uart->port.irq = irq;
|
|
|
|
tasklet_setup(&uart->tasklet, timbuart_tasklet);
|
|
|
|
err = uart_register_driver(&timbuart_driver);
|
|
if (err)
|
|
goto err_register;
|
|
|
|
err = uart_add_one_port(&timbuart_driver, &uart->port);
|
|
if (err)
|
|
goto err_add_port;
|
|
|
|
platform_set_drvdata(dev, uart);
|
|
|
|
return 0;
|
|
|
|
err_add_port:
|
|
uart_unregister_driver(&timbuart_driver);
|
|
err_register:
|
|
kfree(uart);
|
|
err_mem:
|
|
printk(KERN_ERR "timberdale: Failed to register Timberdale UART: %d\n",
|
|
err);
|
|
|
|
return err;
|
|
}
|
|
|
|
static void timbuart_remove(struct platform_device *dev)
|
|
{
|
|
struct timbuart_port *uart = platform_get_drvdata(dev);
|
|
|
|
tasklet_kill(&uart->tasklet);
|
|
uart_remove_one_port(&timbuart_driver, &uart->port);
|
|
uart_unregister_driver(&timbuart_driver);
|
|
kfree(uart);
|
|
}
|
|
|
|
static struct platform_driver timbuart_platform_driver = {
|
|
.driver = {
|
|
.name = "timb-uart",
|
|
},
|
|
.probe = timbuart_probe,
|
|
.remove_new = timbuart_remove,
|
|
};
|
|
|
|
module_platform_driver(timbuart_platform_driver);
|
|
|
|
MODULE_DESCRIPTION("Timberdale UART driver");
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_ALIAS("platform:timb-uart");
|
|
|