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![John Linn](/assets/img/avatar_default.png)
The Xilinx PS Uart is used on the new ARM based SoC. This UART is not compatible with others such that a seperate driver is required. Signed-off-by: John Linn <john.linn@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
1113 lines
31 KiB
C
1113 lines
31 KiB
C
/*
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* Xilinx PS UART driver
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*
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* 2011 (c) Xilinx Inc.
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*
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* This program is free software; you can redistribute it
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* and/or modify it under the terms of the GNU General Public
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* License as published by the Free Software Foundation;
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* either version 2 of the License, or (at your option) any
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* later version.
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*
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*/
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#include <linux/platform_device.h>
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#include <linux/serial_core.h>
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#include <linux/console.h>
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#include <linux/serial.h>
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#include <linux/irq.h>
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#include <linux/io.h>
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#include <linux/of.h>
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#define XUARTPS_TTY_NAME "ttyPS"
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#define XUARTPS_NAME "xuartps"
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#define XUARTPS_MAJOR 0 /* use dynamic node allocation */
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#define XUARTPS_MINOR 0 /* works best with devtmpfs */
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#define XUARTPS_NR_PORTS 2
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#define XUARTPS_FIFO_SIZE 16 /* FIFO size */
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#define XUARTPS_REGISTER_SPACE 0xFFF
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#define xuartps_readl(offset) ioread32(port->membase + offset)
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#define xuartps_writel(val, offset) iowrite32(val, port->membase + offset)
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/********************************Register Map********************************/
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/** UART
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*
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* Register offsets for the UART.
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*
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*/
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#define XUARTPS_CR_OFFSET 0x00 /* Control Register [8:0] */
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#define XUARTPS_MR_OFFSET 0x04 /* Mode Register [10:0] */
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#define XUARTPS_IER_OFFSET 0x08 /* Interrupt Enable [10:0] */
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#define XUARTPS_IDR_OFFSET 0x0C /* Interrupt Disable [10:0] */
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#define XUARTPS_IMR_OFFSET 0x10 /* Interrupt Mask [10:0] */
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#define XUARTPS_ISR_OFFSET 0x14 /* Interrupt Status [10:0]*/
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#define XUARTPS_BAUDGEN_OFFSET 0x18 /* Baud Rate Generator [15:0] */
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#define XUARTPS_RXTOUT_OFFSET 0x1C /* RX Timeout [7:0] */
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#define XUARTPS_RXWM_OFFSET 0x20 /* RX FIFO Trigger Level [5:0] */
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#define XUARTPS_MODEMCR_OFFSET 0x24 /* Modem Control [5:0] */
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#define XUARTPS_MODEMSR_OFFSET 0x28 /* Modem Status [8:0] */
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#define XUARTPS_SR_OFFSET 0x2C /* Channel Status [11:0] */
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#define XUARTPS_FIFO_OFFSET 0x30 /* FIFO [15:0] or [7:0] */
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#define XUARTPS_BAUDDIV_OFFSET 0x34 /* Baud Rate Divider [7:0] */
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#define XUARTPS_FLOWDEL_OFFSET 0x38 /* Flow Delay [15:0] */
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#define XUARTPS_IRRX_PWIDTH_OFFSET 0x3C /* IR Minimum Received Pulse
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Width [15:0] */
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#define XUARTPS_IRTX_PWIDTH_OFFSET 0x40 /* IR Transmitted pulse
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Width [7:0] */
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#define XUARTPS_TXWM_OFFSET 0x44 /* TX FIFO Trigger Level [5:0] */
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/** Control Register
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*
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* The Control register (CR) controls the major functions of the device.
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*
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* Control Register Bit Definitions
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*/
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#define XUARTPS_CR_STOPBRK 0x00000100 /* Stop TX break */
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#define XUARTPS_CR_STARTBRK 0x00000080 /* Set TX break */
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#define XUARTPS_CR_TX_DIS 0x00000020 /* TX disabled. */
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#define XUARTPS_CR_TX_EN 0x00000010 /* TX enabled */
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#define XUARTPS_CR_RX_DIS 0x00000008 /* RX disabled. */
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#define XUARTPS_CR_RX_EN 0x00000004 /* RX enabled */
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#define XUARTPS_CR_TXRST 0x00000002 /* TX logic reset */
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#define XUARTPS_CR_RXRST 0x00000001 /* RX logic reset */
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#define XUARTPS_CR_RST_TO 0x00000040 /* Restart Timeout Counter */
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/** Mode Register
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*
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* The mode register (MR) defines the mode of transfer as well as the data
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* format. If this register is modified during transmission or reception,
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* data validity cannot be guaranteed.
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*
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* Mode Register Bit Definitions
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*
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*/
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#define XUARTPS_MR_CLKSEL 0x00000001 /* Pre-scalar selection */
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#define XUARTPS_MR_CHMODE_L_LOOP 0x00000200 /* Local loop back mode */
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#define XUARTPS_MR_CHMODE_NORM 0x00000000 /* Normal mode */
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#define XUARTPS_MR_STOPMODE_2_BIT 0x00000080 /* 2 stop bits */
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#define XUARTPS_MR_STOPMODE_1_BIT 0x00000000 /* 1 stop bit */
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#define XUARTPS_MR_PARITY_NONE 0x00000020 /* No parity mode */
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#define XUARTPS_MR_PARITY_MARK 0x00000018 /* Mark parity mode */
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#define XUARTPS_MR_PARITY_SPACE 0x00000010 /* Space parity mode */
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#define XUARTPS_MR_PARITY_ODD 0x00000008 /* Odd parity mode */
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#define XUARTPS_MR_PARITY_EVEN 0x00000000 /* Even parity mode */
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#define XUARTPS_MR_CHARLEN_6_BIT 0x00000006 /* 6 bits data */
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#define XUARTPS_MR_CHARLEN_7_BIT 0x00000004 /* 7 bits data */
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#define XUARTPS_MR_CHARLEN_8_BIT 0x00000000 /* 8 bits data */
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/** Interrupt Registers
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*
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* Interrupt control logic uses the interrupt enable register (IER) and the
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* interrupt disable register (IDR) to set the value of the bits in the
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* interrupt mask register (IMR). The IMR determines whether to pass an
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* interrupt to the interrupt status register (ISR).
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* Writing a 1 to IER Enables an interrupt, writing a 1 to IDR disables an
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* interrupt. IMR and ISR are read only, and IER and IDR are write only.
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* Reading either IER or IDR returns 0x00.
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*
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* All four registers have the same bit definitions.
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*/
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#define XUARTPS_IXR_TOUT 0x00000100 /* RX Timeout error interrupt */
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#define XUARTPS_IXR_PARITY 0x00000080 /* Parity error interrupt */
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#define XUARTPS_IXR_FRAMING 0x00000040 /* Framing error interrupt */
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#define XUARTPS_IXR_OVERRUN 0x00000020 /* Overrun error interrupt */
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#define XUARTPS_IXR_TXFULL 0x00000010 /* TX FIFO Full interrupt */
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#define XUARTPS_IXR_TXEMPTY 0x00000008 /* TX FIFO empty interrupt */
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#define XUARTPS_ISR_RXEMPTY 0x00000002 /* RX FIFO empty interrupt */
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#define XUARTPS_IXR_RXTRIG 0x00000001 /* RX FIFO trigger interrupt */
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#define XUARTPS_IXR_RXFULL 0x00000004 /* RX FIFO full interrupt. */
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#define XUARTPS_IXR_RXEMPTY 0x00000002 /* RX FIFO empty interrupt. */
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#define XUARTPS_IXR_MASK 0x00001FFF /* Valid bit mask */
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/** Channel Status Register
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*
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* The channel status register (CSR) is provided to enable the control logic
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* to monitor the status of bits in the channel interrupt status register,
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* even if these are masked out by the interrupt mask register.
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*/
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#define XUARTPS_SR_RXEMPTY 0x00000002 /* RX FIFO empty */
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#define XUARTPS_SR_TXEMPTY 0x00000008 /* TX FIFO empty */
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#define XUARTPS_SR_TXFULL 0x00000010 /* TX FIFO full */
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#define XUARTPS_SR_RXTRIG 0x00000001 /* Rx Trigger */
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/**
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* xuartps_isr - Interrupt handler
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* @irq: Irq number
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* @dev_id: Id of the port
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*
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* Returns IRQHANDLED
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**/
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static irqreturn_t xuartps_isr(int irq, void *dev_id)
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{
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struct uart_port *port = (struct uart_port *)dev_id;
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struct tty_struct *tty;
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unsigned long flags;
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unsigned int isrstatus, numbytes;
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unsigned int data;
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char status = TTY_NORMAL;
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/* Get the tty which could be NULL so don't assume it's valid */
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tty = tty_port_tty_get(&port->state->port);
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spin_lock_irqsave(&port->lock, flags);
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/* Read the interrupt status register to determine which
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* interrupt(s) is/are active.
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*/
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isrstatus = xuartps_readl(XUARTPS_ISR_OFFSET);
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/* drop byte with parity error if IGNPAR specified */
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if (isrstatus & port->ignore_status_mask & XUARTPS_IXR_PARITY)
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isrstatus &= ~(XUARTPS_IXR_RXTRIG | XUARTPS_IXR_TOUT);
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isrstatus &= port->read_status_mask;
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isrstatus &= ~port->ignore_status_mask;
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if ((isrstatus & XUARTPS_IXR_TOUT) ||
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(isrstatus & XUARTPS_IXR_RXTRIG)) {
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/* Receive Timeout Interrupt */
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while ((xuartps_readl(XUARTPS_SR_OFFSET) &
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XUARTPS_SR_RXEMPTY) != XUARTPS_SR_RXEMPTY) {
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data = xuartps_readl(XUARTPS_FIFO_OFFSET);
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port->icount.rx++;
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if (isrstatus & XUARTPS_IXR_PARITY) {
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port->icount.parity++;
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status = TTY_PARITY;
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} else if (isrstatus & XUARTPS_IXR_FRAMING) {
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port->icount.frame++;
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status = TTY_FRAME;
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} else if (isrstatus & XUARTPS_IXR_OVERRUN)
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port->icount.overrun++;
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if (tty)
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uart_insert_char(port, isrstatus,
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XUARTPS_IXR_OVERRUN, data,
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status);
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}
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spin_unlock(&port->lock);
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if (tty)
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tty_flip_buffer_push(tty);
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spin_lock(&port->lock);
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}
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/* Dispatch an appropriate handler */
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if ((isrstatus & XUARTPS_IXR_TXEMPTY) == XUARTPS_IXR_TXEMPTY) {
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if (uart_circ_empty(&port->state->xmit)) {
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xuartps_writel(XUARTPS_IXR_TXEMPTY,
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XUARTPS_IDR_OFFSET);
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} else {
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numbytes = port->fifosize;
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/* Break if no more data available in the UART buffer */
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while (numbytes--) {
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if (uart_circ_empty(&port->state->xmit))
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break;
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/* Get the data from the UART circular buffer
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* and write it to the xuartps's TX_FIFO
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* register.
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*/
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xuartps_writel(
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port->state->xmit.buf[port->state->xmit.
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tail], XUARTPS_FIFO_OFFSET);
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port->icount.tx++;
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/* Adjust the tail of the UART buffer and wrap
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* the buffer if it reaches limit.
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*/
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port->state->xmit.tail =
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(port->state->xmit.tail + 1) & \
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(UART_XMIT_SIZE - 1);
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}
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if (uart_circ_chars_pending(
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&port->state->xmit) < WAKEUP_CHARS)
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uart_write_wakeup(port);
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}
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}
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xuartps_writel(isrstatus, XUARTPS_ISR_OFFSET);
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/* be sure to release the lock and tty before leaving */
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spin_unlock_irqrestore(&port->lock, flags);
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tty_kref_put(tty);
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return IRQ_HANDLED;
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}
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/**
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* xuartps_set_baud_rate - Calculate and set the baud rate
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* @port: Handle to the uart port structure
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* @baud: Baud rate to set
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*
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* Returns baud rate, requested baud when possible, or actual baud when there
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* was too much error
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**/
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static unsigned int xuartps_set_baud_rate(struct uart_port *port,
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unsigned int baud)
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{
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unsigned int sel_clk;
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unsigned int calc_baud = 0;
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unsigned int brgr_val, brdiv_val;
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unsigned int bauderror;
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/* Formula to obtain baud rate is
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* baud_tx/rx rate = sel_clk/CD * (BDIV + 1)
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* input_clk = (Uart User Defined Clock or Apb Clock)
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* depends on UCLKEN in MR Reg
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* sel_clk = input_clk or input_clk/8;
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* depends on CLKS in MR reg
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* CD and BDIV depends on values in
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* baud rate generate register
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* baud rate clock divisor register
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*/
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sel_clk = port->uartclk;
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if (xuartps_readl(XUARTPS_MR_OFFSET) & XUARTPS_MR_CLKSEL)
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sel_clk = sel_clk / 8;
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/* Find the best values for baud generation */
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for (brdiv_val = 4; brdiv_val < 255; brdiv_val++) {
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brgr_val = sel_clk / (baud * (brdiv_val + 1));
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if (brgr_val < 2 || brgr_val > 65535)
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continue;
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calc_baud = sel_clk / (brgr_val * (brdiv_val + 1));
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if (baud > calc_baud)
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bauderror = baud - calc_baud;
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else
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bauderror = calc_baud - baud;
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/* use the values when percent error is acceptable */
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if (((bauderror * 100) / baud) < 3) {
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calc_baud = baud;
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break;
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}
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}
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/* Set the values for the new baud rate */
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xuartps_writel(brgr_val, XUARTPS_BAUDGEN_OFFSET);
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xuartps_writel(brdiv_val, XUARTPS_BAUDDIV_OFFSET);
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return calc_baud;
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}
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/*----------------------Uart Operations---------------------------*/
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/**
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* xuartps_start_tx - Start transmitting bytes
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* @port: Handle to the uart port structure
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*
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**/
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static void xuartps_start_tx(struct uart_port *port)
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{
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unsigned int status, numbytes = port->fifosize;
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if (uart_circ_empty(&port->state->xmit) || uart_tx_stopped(port))
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return;
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status = xuartps_readl(XUARTPS_CR_OFFSET);
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/* Set the TX enable bit and clear the TX disable bit to enable the
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* transmitter.
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*/
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xuartps_writel((status & ~XUARTPS_CR_TX_DIS) | XUARTPS_CR_TX_EN,
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XUARTPS_CR_OFFSET);
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while (numbytes-- && ((xuartps_readl(XUARTPS_SR_OFFSET)
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& XUARTPS_SR_TXFULL)) != XUARTPS_SR_TXFULL) {
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/* Break if no more data available in the UART buffer */
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if (uart_circ_empty(&port->state->xmit))
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break;
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/* Get the data from the UART circular buffer and
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* write it to the xuartps's TX_FIFO register.
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*/
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xuartps_writel(
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port->state->xmit.buf[port->state->xmit.tail],
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XUARTPS_FIFO_OFFSET);
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port->icount.tx++;
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/* Adjust the tail of the UART buffer and wrap
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* the buffer if it reaches limit.
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*/
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port->state->xmit.tail = (port->state->xmit.tail + 1) &
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(UART_XMIT_SIZE - 1);
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}
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/* Enable the TX Empty interrupt */
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xuartps_writel(XUARTPS_IXR_TXEMPTY, XUARTPS_IER_OFFSET);
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if (uart_circ_chars_pending(&port->state->xmit) < WAKEUP_CHARS)
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uart_write_wakeup(port);
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}
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/**
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* xuartps_stop_tx - Stop TX
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* @port: Handle to the uart port structure
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*
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**/
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static void xuartps_stop_tx(struct uart_port *port)
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{
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unsigned int regval;
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regval = xuartps_readl(XUARTPS_CR_OFFSET);
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regval |= XUARTPS_CR_TX_DIS;
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/* Disable the transmitter */
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xuartps_writel(regval, XUARTPS_CR_OFFSET);
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}
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/**
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* xuartps_stop_rx - Stop RX
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* @port: Handle to the uart port structure
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*
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**/
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static void xuartps_stop_rx(struct uart_port *port)
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{
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unsigned int regval;
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regval = xuartps_readl(XUARTPS_CR_OFFSET);
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regval |= XUARTPS_CR_RX_DIS;
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/* Disable the receiver */
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xuartps_writel(regval, XUARTPS_CR_OFFSET);
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}
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/**
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* xuartps_tx_empty - Check whether TX is empty
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* @port: Handle to the uart port structure
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*
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* Returns TIOCSER_TEMT on success, 0 otherwise
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**/
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static unsigned int xuartps_tx_empty(struct uart_port *port)
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{
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unsigned int status;
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status = xuartps_readl(XUARTPS_ISR_OFFSET) & XUARTPS_IXR_TXEMPTY;
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return status ? TIOCSER_TEMT : 0;
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}
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/**
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* xuartps_break_ctl - Based on the input ctl we have to start or stop
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* transmitting char breaks
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* @port: Handle to the uart port structure
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* @ctl: Value based on which start or stop decision is taken
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*
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**/
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static void xuartps_break_ctl(struct uart_port *port, int ctl)
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{
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unsigned int status;
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unsigned long flags;
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spin_lock_irqsave(&port->lock, flags);
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status = xuartps_readl(XUARTPS_CR_OFFSET);
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if (ctl == -1)
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xuartps_writel(XUARTPS_CR_STARTBRK | status,
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XUARTPS_CR_OFFSET);
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else {
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if ((status & XUARTPS_CR_STOPBRK) == 0)
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xuartps_writel(XUARTPS_CR_STOPBRK | status,
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XUARTPS_CR_OFFSET);
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}
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spin_unlock_irqrestore(&port->lock, flags);
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}
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/**
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* xuartps_set_termios - termios operations, handling data length, parity,
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* stop bits, flow control, baud rate
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* @port: Handle to the uart port structure
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* @termios: Handle to the input termios structure
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* @old: Values of the previously saved termios structure
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*
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**/
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static void xuartps_set_termios(struct uart_port *port,
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struct ktermios *termios, struct ktermios *old)
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{
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unsigned int cval = 0;
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unsigned int baud;
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unsigned long flags;
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unsigned int ctrl_reg, mode_reg;
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spin_lock_irqsave(&port->lock, flags);
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/* Empty the receive FIFO 1st before making changes */
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while ((xuartps_readl(XUARTPS_SR_OFFSET) &
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XUARTPS_SR_RXEMPTY) != XUARTPS_SR_RXEMPTY) {
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xuartps_readl(XUARTPS_FIFO_OFFSET);
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}
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/* Disable the TX and RX to set baud rate */
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xuartps_writel(xuartps_readl(XUARTPS_CR_OFFSET) |
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(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS),
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XUARTPS_CR_OFFSET);
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/* Min baud rate = 6bps and Max Baud Rate is 10Mbps for 100Mhz clk */
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baud = uart_get_baud_rate(port, termios, old, 0, 10000000);
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baud = xuartps_set_baud_rate(port, baud);
|
|
if (tty_termios_baud_rate(termios))
|
|
tty_termios_encode_baud_rate(termios, baud, baud);
|
|
|
|
/*
|
|
* Update the per-port timeout.
|
|
*/
|
|
uart_update_timeout(port, termios->c_cflag, baud);
|
|
|
|
/* Set TX/RX Reset */
|
|
xuartps_writel(xuartps_readl(XUARTPS_CR_OFFSET) |
|
|
(XUARTPS_CR_TXRST | XUARTPS_CR_RXRST),
|
|
XUARTPS_CR_OFFSET);
|
|
|
|
ctrl_reg = xuartps_readl(XUARTPS_CR_OFFSET);
|
|
|
|
/* Clear the RX disable and TX disable bits and then set the TX enable
|
|
* bit and RX enable bit to enable the transmitter and receiver.
|
|
*/
|
|
xuartps_writel(
|
|
(ctrl_reg & ~(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS))
|
|
| (XUARTPS_CR_TX_EN | XUARTPS_CR_RX_EN),
|
|
XUARTPS_CR_OFFSET);
|
|
|
|
xuartps_writel(10, XUARTPS_RXTOUT_OFFSET);
|
|
|
|
port->read_status_mask = XUARTPS_IXR_TXEMPTY | XUARTPS_IXR_RXTRIG |
|
|
XUARTPS_IXR_OVERRUN | XUARTPS_IXR_TOUT;
|
|
port->ignore_status_mask = 0;
|
|
|
|
if (termios->c_iflag & INPCK)
|
|
port->read_status_mask |= XUARTPS_IXR_PARITY |
|
|
XUARTPS_IXR_FRAMING;
|
|
|
|
if (termios->c_iflag & IGNPAR)
|
|
port->ignore_status_mask |= XUARTPS_IXR_PARITY |
|
|
XUARTPS_IXR_FRAMING | XUARTPS_IXR_OVERRUN;
|
|
|
|
/* ignore all characters if CREAD is not set */
|
|
if ((termios->c_cflag & CREAD) == 0)
|
|
port->ignore_status_mask |= XUARTPS_IXR_RXTRIG |
|
|
XUARTPS_IXR_TOUT | XUARTPS_IXR_PARITY |
|
|
XUARTPS_IXR_FRAMING | XUARTPS_IXR_OVERRUN;
|
|
|
|
mode_reg = xuartps_readl(XUARTPS_MR_OFFSET);
|
|
|
|
/* Handling Data Size */
|
|
switch (termios->c_cflag & CSIZE) {
|
|
case CS6:
|
|
cval |= XUARTPS_MR_CHARLEN_6_BIT;
|
|
break;
|
|
case CS7:
|
|
cval |= XUARTPS_MR_CHARLEN_7_BIT;
|
|
break;
|
|
default:
|
|
case CS8:
|
|
cval |= XUARTPS_MR_CHARLEN_8_BIT;
|
|
termios->c_cflag &= ~CSIZE;
|
|
termios->c_cflag |= CS8;
|
|
break;
|
|
}
|
|
|
|
/* Handling Parity and Stop Bits length */
|
|
if (termios->c_cflag & CSTOPB)
|
|
cval |= XUARTPS_MR_STOPMODE_2_BIT; /* 2 STOP bits */
|
|
else
|
|
cval |= XUARTPS_MR_STOPMODE_1_BIT; /* 1 STOP bit */
|
|
|
|
if (termios->c_cflag & PARENB) {
|
|
/* Mark or Space parity */
|
|
if (termios->c_cflag & CMSPAR) {
|
|
if (termios->c_cflag & PARODD)
|
|
cval |= XUARTPS_MR_PARITY_MARK;
|
|
else
|
|
cval |= XUARTPS_MR_PARITY_SPACE;
|
|
} else if (termios->c_cflag & PARODD)
|
|
cval |= XUARTPS_MR_PARITY_ODD;
|
|
else
|
|
cval |= XUARTPS_MR_PARITY_EVEN;
|
|
} else
|
|
cval |= XUARTPS_MR_PARITY_NONE;
|
|
xuartps_writel(cval , XUARTPS_MR_OFFSET);
|
|
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
}
|
|
|
|
/**
|
|
* xuartps_startup - Called when an application opens a xuartps port
|
|
* @port: Handle to the uart port structure
|
|
*
|
|
* Returns 0 on success, negative error otherwise
|
|
**/
|
|
static int xuartps_startup(struct uart_port *port)
|
|
{
|
|
unsigned int retval = 0, status = 0;
|
|
|
|
retval = request_irq(port->irq, xuartps_isr, 0, XUARTPS_NAME,
|
|
(void *)port);
|
|
if (retval)
|
|
return retval;
|
|
|
|
/* Disable the TX and RX */
|
|
xuartps_writel(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS,
|
|
XUARTPS_CR_OFFSET);
|
|
|
|
/* Set the Control Register with TX/RX Enable, TX/RX Reset,
|
|
* no break chars.
|
|
*/
|
|
xuartps_writel(XUARTPS_CR_TXRST | XUARTPS_CR_RXRST,
|
|
XUARTPS_CR_OFFSET);
|
|
|
|
status = xuartps_readl(XUARTPS_CR_OFFSET);
|
|
|
|
/* Clear the RX disable and TX disable bits and then set the TX enable
|
|
* bit and RX enable bit to enable the transmitter and receiver.
|
|
*/
|
|
xuartps_writel((status & ~(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS))
|
|
| (XUARTPS_CR_TX_EN | XUARTPS_CR_RX_EN |
|
|
XUARTPS_CR_STOPBRK), XUARTPS_CR_OFFSET);
|
|
|
|
/* Set the Mode Register with normal mode,8 data bits,1 stop bit,
|
|
* no parity.
|
|
*/
|
|
xuartps_writel(XUARTPS_MR_CHMODE_NORM | XUARTPS_MR_STOPMODE_1_BIT
|
|
| XUARTPS_MR_PARITY_NONE | XUARTPS_MR_CHARLEN_8_BIT,
|
|
XUARTPS_MR_OFFSET);
|
|
|
|
/* Set the RX FIFO Trigger level to 14 assuming FIFO size as 16 */
|
|
xuartps_writel(14, XUARTPS_RXWM_OFFSET);
|
|
|
|
/* Receive Timeout register is enabled with value of 10 */
|
|
xuartps_writel(10, XUARTPS_RXTOUT_OFFSET);
|
|
|
|
|
|
/* Set the Interrupt Registers with desired interrupts */
|
|
xuartps_writel(XUARTPS_IXR_TXEMPTY | XUARTPS_IXR_PARITY |
|
|
XUARTPS_IXR_FRAMING | XUARTPS_IXR_OVERRUN |
|
|
XUARTPS_IXR_RXTRIG | XUARTPS_IXR_TOUT, XUARTPS_IER_OFFSET);
|
|
xuartps_writel(~(XUARTPS_IXR_TXEMPTY | XUARTPS_IXR_PARITY |
|
|
XUARTPS_IXR_FRAMING | XUARTPS_IXR_OVERRUN |
|
|
XUARTPS_IXR_RXTRIG | XUARTPS_IXR_TOUT), XUARTPS_IDR_OFFSET);
|
|
|
|
return retval;
|
|
}
|
|
|
|
/**
|
|
* xuartps_shutdown - Called when an application closes a xuartps port
|
|
* @port: Handle to the uart port structure
|
|
*
|
|
**/
|
|
static void xuartps_shutdown(struct uart_port *port)
|
|
{
|
|
int status;
|
|
|
|
/* Disable interrupts */
|
|
status = xuartps_readl(XUARTPS_IMR_OFFSET);
|
|
xuartps_writel(status, XUARTPS_IDR_OFFSET);
|
|
|
|
/* Disable the TX and RX */
|
|
xuartps_writel(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS,
|
|
XUARTPS_CR_OFFSET);
|
|
free_irq(port->irq, port);
|
|
}
|
|
|
|
/**
|
|
* xuartps_type - Set UART type to xuartps port
|
|
* @port: Handle to the uart port structure
|
|
*
|
|
* Returns string on success, NULL otherwise
|
|
**/
|
|
static const char *xuartps_type(struct uart_port *port)
|
|
{
|
|
return port->type == PORT_XUARTPS ? XUARTPS_NAME : NULL;
|
|
}
|
|
|
|
/**
|
|
* xuartps_verify_port - Verify the port params
|
|
* @port: Handle to the uart port structure
|
|
* @ser: Handle to the structure whose members are compared
|
|
*
|
|
* Returns 0 if success otherwise -EINVAL
|
|
**/
|
|
static int xuartps_verify_port(struct uart_port *port,
|
|
struct serial_struct *ser)
|
|
{
|
|
if (ser->type != PORT_UNKNOWN && ser->type != PORT_XUARTPS)
|
|
return -EINVAL;
|
|
if (port->irq != ser->irq)
|
|
return -EINVAL;
|
|
if (ser->io_type != UPIO_MEM)
|
|
return -EINVAL;
|
|
if (port->iobase != ser->port)
|
|
return -EINVAL;
|
|
if (ser->hub6 != 0)
|
|
return -EINVAL;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* xuartps_request_port - Claim the memory region attached to xuartps port,
|
|
* called when the driver adds a xuartps port via
|
|
* uart_add_one_port()
|
|
* @port: Handle to the uart port structure
|
|
*
|
|
* Returns 0, -ENOMEM if request fails
|
|
**/
|
|
static int xuartps_request_port(struct uart_port *port)
|
|
{
|
|
if (!request_mem_region(port->mapbase, XUARTPS_REGISTER_SPACE,
|
|
XUARTPS_NAME)) {
|
|
return -ENOMEM;
|
|
}
|
|
|
|
port->membase = ioremap(port->mapbase, XUARTPS_REGISTER_SPACE);
|
|
if (!port->membase) {
|
|
dev_err(port->dev, "Unable to map registers\n");
|
|
release_mem_region(port->mapbase, XUARTPS_REGISTER_SPACE);
|
|
return -ENOMEM;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* xuartps_release_port - Release the memory region attached to a xuartps
|
|
* port, called when the driver removes a xuartps
|
|
* port via uart_remove_one_port().
|
|
* @port: Handle to the uart port structure
|
|
*
|
|
**/
|
|
static void xuartps_release_port(struct uart_port *port)
|
|
{
|
|
release_mem_region(port->mapbase, XUARTPS_REGISTER_SPACE);
|
|
iounmap(port->membase);
|
|
port->membase = NULL;
|
|
}
|
|
|
|
/**
|
|
* xuartps_config_port - Configure xuartps, called when the driver adds a
|
|
* xuartps port
|
|
* @port: Handle to the uart port structure
|
|
* @flags: If any
|
|
*
|
|
**/
|
|
static void xuartps_config_port(struct uart_port *port, int flags)
|
|
{
|
|
if (flags & UART_CONFIG_TYPE && xuartps_request_port(port) == 0)
|
|
port->type = PORT_XUARTPS;
|
|
}
|
|
|
|
/**
|
|
* xuartps_get_mctrl - Get the modem control state
|
|
*
|
|
* @port: Handle to the uart port structure
|
|
*
|
|
* Returns the modem control state
|
|
*
|
|
**/
|
|
static unsigned int xuartps_get_mctrl(struct uart_port *port)
|
|
{
|
|
return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
|
|
}
|
|
|
|
static void xuartps_set_mctrl(struct uart_port *port, unsigned int mctrl)
|
|
{
|
|
/* N/A */
|
|
}
|
|
|
|
static void xuartps_enable_ms(struct uart_port *port)
|
|
{
|
|
/* N/A */
|
|
}
|
|
|
|
/** The UART operations structure
|
|
*/
|
|
static struct uart_ops xuartps_ops = {
|
|
.set_mctrl = xuartps_set_mctrl,
|
|
.get_mctrl = xuartps_get_mctrl,
|
|
.enable_ms = xuartps_enable_ms,
|
|
|
|
.start_tx = xuartps_start_tx, /* Start transmitting */
|
|
.stop_tx = xuartps_stop_tx, /* Stop transmission */
|
|
.stop_rx = xuartps_stop_rx, /* Stop reception */
|
|
.tx_empty = xuartps_tx_empty, /* Transmitter busy? */
|
|
.break_ctl = xuartps_break_ctl, /* Start/stop
|
|
* transmitting break
|
|
*/
|
|
.set_termios = xuartps_set_termios, /* Set termios */
|
|
.startup = xuartps_startup, /* App opens xuartps */
|
|
.shutdown = xuartps_shutdown, /* App closes xuartps */
|
|
.type = xuartps_type, /* Set UART type */
|
|
.verify_port = xuartps_verify_port, /* Verification of port
|
|
* params
|
|
*/
|
|
.request_port = xuartps_request_port, /* Claim resources
|
|
* associated with a
|
|
* xuartps port
|
|
*/
|
|
.release_port = xuartps_release_port, /* Release resources
|
|
* associated with a
|
|
* xuartps port
|
|
*/
|
|
.config_port = xuartps_config_port, /* Configure when driver
|
|
* adds a xuartps port
|
|
*/
|
|
};
|
|
|
|
static struct uart_port xuartps_port[2];
|
|
|
|
/**
|
|
* xuartps_get_port - Configure the port from the platform device resource
|
|
* info
|
|
*
|
|
* Returns a pointer to a uart_port or NULL for failure
|
|
**/
|
|
static struct uart_port *xuartps_get_port(void)
|
|
{
|
|
struct uart_port *port;
|
|
int id;
|
|
|
|
/* Find the next unused port */
|
|
for (id = 0; id < XUARTPS_NR_PORTS; id++)
|
|
if (xuartps_port[id].mapbase == 0)
|
|
break;
|
|
|
|
if (id >= XUARTPS_NR_PORTS)
|
|
return NULL;
|
|
|
|
port = &xuartps_port[id];
|
|
|
|
/* At this point, we've got an empty uart_port struct, initialize it */
|
|
spin_lock_init(&port->lock);
|
|
port->membase = NULL;
|
|
port->iobase = 1; /* mark port in use */
|
|
port->irq = 0;
|
|
port->type = PORT_UNKNOWN;
|
|
port->iotype = UPIO_MEM32;
|
|
port->flags = UPF_BOOT_AUTOCONF;
|
|
port->ops = &xuartps_ops;
|
|
port->fifosize = XUARTPS_FIFO_SIZE;
|
|
port->line = id;
|
|
port->dev = NULL;
|
|
return port;
|
|
}
|
|
|
|
/*-----------------------Console driver operations--------------------------*/
|
|
|
|
#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
|
|
/**
|
|
* xuartps_console_wait_tx - Wait for the TX to be full
|
|
* @port: Handle to the uart port structure
|
|
*
|
|
**/
|
|
static void xuartps_console_wait_tx(struct uart_port *port)
|
|
{
|
|
while ((xuartps_readl(XUARTPS_SR_OFFSET) & XUARTPS_SR_TXEMPTY)
|
|
!= XUARTPS_SR_TXEMPTY)
|
|
barrier();
|
|
}
|
|
|
|
/**
|
|
* xuartps_console_putchar - write the character to the FIFO buffer
|
|
* @port: Handle to the uart port structure
|
|
* @ch: Character to be written
|
|
*
|
|
**/
|
|
static void xuartps_console_putchar(struct uart_port *port, int ch)
|
|
{
|
|
xuartps_console_wait_tx(port);
|
|
xuartps_writel(ch, XUARTPS_FIFO_OFFSET);
|
|
}
|
|
|
|
/**
|
|
* xuartps_console_write - perform write operation
|
|
* @port: Handle to the uart port structure
|
|
* @s: Pointer to character array
|
|
* @count: No of characters
|
|
**/
|
|
static void xuartps_console_write(struct console *co, const char *s,
|
|
unsigned int count)
|
|
{
|
|
struct uart_port *port = &xuartps_port[co->index];
|
|
unsigned long flags;
|
|
unsigned int imr;
|
|
int locked = 1;
|
|
|
|
if (oops_in_progress)
|
|
locked = spin_trylock_irqsave(&port->lock, flags);
|
|
else
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
|
|
/* save and disable interrupt */
|
|
imr = xuartps_readl(XUARTPS_IMR_OFFSET);
|
|
xuartps_writel(imr, XUARTPS_IDR_OFFSET);
|
|
|
|
uart_console_write(port, s, count, xuartps_console_putchar);
|
|
xuartps_console_wait_tx(port);
|
|
|
|
/* restore interrupt state, it seems like there may be a h/w bug
|
|
* in that the interrupt enable register should not need to be
|
|
* written based on the data sheet
|
|
*/
|
|
xuartps_writel(~imr, XUARTPS_IDR_OFFSET);
|
|
xuartps_writel(imr, XUARTPS_IER_OFFSET);
|
|
|
|
if (locked)
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
}
|
|
|
|
/**
|
|
* xuartps_console_setup - Initialize the uart to default config
|
|
* @co: Console handle
|
|
* @options: Initial settings of uart
|
|
*
|
|
* Returns 0, -ENODEV if no device
|
|
**/
|
|
static int __init xuartps_console_setup(struct console *co, char *options)
|
|
{
|
|
struct uart_port *port = &xuartps_port[co->index];
|
|
int baud = 9600;
|
|
int bits = 8;
|
|
int parity = 'n';
|
|
int flow = 'n';
|
|
|
|
if (co->index < 0 || co->index >= XUARTPS_NR_PORTS)
|
|
return -EINVAL;
|
|
|
|
if (!port->mapbase) {
|
|
pr_debug("console on ttyPS%i not present\n", co->index);
|
|
return -ENODEV;
|
|
}
|
|
|
|
if (options)
|
|
uart_parse_options(options, &baud, &parity, &bits, &flow);
|
|
|
|
return uart_set_options(port, co, baud, parity, bits, flow);
|
|
}
|
|
|
|
static struct uart_driver xuartps_uart_driver;
|
|
|
|
static struct console xuartps_console = {
|
|
.name = XUARTPS_TTY_NAME,
|
|
.write = xuartps_console_write,
|
|
.device = uart_console_device,
|
|
.setup = xuartps_console_setup,
|
|
.flags = CON_PRINTBUFFER,
|
|
.index = -1, /* Specified on the cmdline (e.g. console=ttyPS ) */
|
|
.data = &xuartps_uart_driver,
|
|
};
|
|
|
|
/**
|
|
* xuartps_console_init - Initialization call
|
|
*
|
|
* Returns 0 on success, negative error otherwise
|
|
**/
|
|
static int __init xuartps_console_init(void)
|
|
{
|
|
register_console(&xuartps_console);
|
|
return 0;
|
|
}
|
|
|
|
console_initcall(xuartps_console_init);
|
|
|
|
#endif /* CONFIG_SERIAL_XILINX_PS_UART_CONSOLE */
|
|
|
|
/** Structure Definitions
|
|
*/
|
|
static struct uart_driver xuartps_uart_driver = {
|
|
.owner = THIS_MODULE, /* Owner */
|
|
.driver_name = XUARTPS_NAME, /* Driver name */
|
|
.dev_name = XUARTPS_TTY_NAME, /* Node name */
|
|
.major = XUARTPS_MAJOR, /* Major number */
|
|
.minor = XUARTPS_MINOR, /* Minor number */
|
|
.nr = XUARTPS_NR_PORTS, /* Number of UART ports */
|
|
#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
|
|
.cons = &xuartps_console, /* Console */
|
|
#endif
|
|
};
|
|
|
|
/* ---------------------------------------------------------------------
|
|
* Platform bus binding
|
|
*/
|
|
/**
|
|
* xuartps_probe - Platform driver probe
|
|
* @pdev: Pointer to the platform device structure
|
|
*
|
|
* Returns 0 on success, negative error otherwise
|
|
**/
|
|
static int __devinit xuartps_probe(struct platform_device *pdev)
|
|
{
|
|
int rc;
|
|
struct uart_port *port;
|
|
struct resource *res, *res2;
|
|
int clk = 0;
|
|
|
|
#ifdef CONFIG_OF
|
|
const unsigned int *prop;
|
|
|
|
prop = of_get_property(pdev->dev.of_node, "clock", NULL);
|
|
if (prop)
|
|
clk = be32_to_cpup(prop);
|
|
#else
|
|
clk = *((unsigned int *)(pdev->dev.platform_data));
|
|
#endif
|
|
if (!clk) {
|
|
dev_err(&pdev->dev, "no clock specified\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
if (!res)
|
|
return -ENODEV;
|
|
|
|
res2 = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
|
|
if (!res2)
|
|
return -ENODEV;
|
|
|
|
/* Initialize the port structure */
|
|
port = xuartps_get_port();
|
|
|
|
if (!port) {
|
|
dev_err(&pdev->dev, "Cannot get uart_port structure\n");
|
|
return -ENODEV;
|
|
} else {
|
|
/* Register the port.
|
|
* This function also registers this device with the tty layer
|
|
* and triggers invocation of the config_port() entry point.
|
|
*/
|
|
port->mapbase = res->start;
|
|
port->irq = res2->start;
|
|
port->dev = &pdev->dev;
|
|
port->uartclk = clk;
|
|
dev_set_drvdata(&pdev->dev, port);
|
|
rc = uart_add_one_port(&xuartps_uart_driver, port);
|
|
if (rc) {
|
|
dev_err(&pdev->dev,
|
|
"uart_add_one_port() failed; err=%i\n", rc);
|
|
dev_set_drvdata(&pdev->dev, NULL);
|
|
return rc;
|
|
}
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* xuartps_remove - called when the platform driver is unregistered
|
|
* @pdev: Pointer to the platform device structure
|
|
*
|
|
* Returns 0 on success, negative error otherwise
|
|
**/
|
|
static int __devexit xuartps_remove(struct platform_device *pdev)
|
|
{
|
|
struct uart_port *port = dev_get_drvdata(&pdev->dev);
|
|
int rc = 0;
|
|
|
|
/* Remove the xuartps port from the serial core */
|
|
if (port) {
|
|
rc = uart_remove_one_port(&xuartps_uart_driver, port);
|
|
dev_set_drvdata(&pdev->dev, NULL);
|
|
port->mapbase = 0;
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* xuartps_suspend - suspend event
|
|
* @pdev: Pointer to the platform device structure
|
|
* @state: State of the device
|
|
*
|
|
* Returns 0
|
|
**/
|
|
static int xuartps_suspend(struct platform_device *pdev, pm_message_t state)
|
|
{
|
|
/* Call the API provided in serial_core.c file which handles
|
|
* the suspend.
|
|
*/
|
|
uart_suspend_port(&xuartps_uart_driver, &xuartps_port[pdev->id]);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* xuartps_resume - Resume after a previous suspend
|
|
* @pdev: Pointer to the platform device structure
|
|
*
|
|
* Returns 0
|
|
**/
|
|
static int xuartps_resume(struct platform_device *pdev)
|
|
{
|
|
uart_resume_port(&xuartps_uart_driver, &xuartps_port[pdev->id]);
|
|
return 0;
|
|
}
|
|
|
|
/* Match table for of_platform binding */
|
|
|
|
#ifdef CONFIG_OF
|
|
static struct of_device_id xuartps_of_match[] __devinitdata = {
|
|
{ .compatible = "xlnx,xuartps", },
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(of, xuartps_of_match);
|
|
#else
|
|
#define xuartps_of_match NULL
|
|
#endif
|
|
|
|
static struct platform_driver xuartps_platform_driver = {
|
|
.probe = xuartps_probe, /* Probe method */
|
|
.remove = __exit_p(xuartps_remove), /* Detach method */
|
|
.suspend = xuartps_suspend, /* Suspend */
|
|
.resume = xuartps_resume, /* Resume after a suspend */
|
|
.driver = {
|
|
.owner = THIS_MODULE,
|
|
.name = XUARTPS_NAME, /* Driver name */
|
|
.of_match_table = xuartps_of_match,
|
|
},
|
|
};
|
|
|
|
/* ---------------------------------------------------------------------
|
|
* Module Init and Exit
|
|
*/
|
|
/**
|
|
* xuartps_init - Initial driver registration call
|
|
*
|
|
* Returns whether the registration was successful or not
|
|
**/
|
|
static int __init xuartps_init(void)
|
|
{
|
|
int retval = 0;
|
|
|
|
/* Register the xuartps driver with the serial core */
|
|
retval = uart_register_driver(&xuartps_uart_driver);
|
|
if (retval)
|
|
return retval;
|
|
|
|
/* Register the platform driver */
|
|
retval = platform_driver_register(&xuartps_platform_driver);
|
|
if (retval)
|
|
uart_unregister_driver(&xuartps_uart_driver);
|
|
|
|
return retval;
|
|
}
|
|
|
|
/**
|
|
* xuartps_exit - Driver unregistration call
|
|
**/
|
|
static void __exit xuartps_exit(void)
|
|
{
|
|
/* The order of unregistration is important. Unregister the
|
|
* UART driver before the platform driver crashes the system.
|
|
*/
|
|
|
|
/* Unregister the platform driver */
|
|
platform_driver_unregister(&xuartps_platform_driver);
|
|
|
|
/* Unregister the xuartps driver */
|
|
uart_unregister_driver(&xuartps_uart_driver);
|
|
}
|
|
|
|
module_init(xuartps_init);
|
|
module_exit(xuartps_exit);
|
|
|
|
MODULE_DESCRIPTION("Driver for PS UART");
|
|
MODULE_AUTHOR("Xilinx Inc.");
|
|
MODULE_LICENSE("GPL");
|