372 lines
10 KiB
C
372 lines
10 KiB
C
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// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Xilinx XPS PS/2 device driver
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*
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* (c) 2005 MontaVista Software, Inc.
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* (c) 2008 Xilinx, Inc.
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*/
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#include <linux/module.h>
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#include <linux/serio.h>
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#include <linux/interrupt.h>
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#include <linux/errno.h>
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#include <linux/slab.h>
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#include <linux/list.h>
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#include <linux/io.h>
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#include <linux/of_address.h>
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#include <linux/of_device.h>
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#include <linux/of_irq.h>
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#include <linux/of_platform.h>
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#define DRIVER_NAME "xilinx_ps2"
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/* Register offsets for the xps2 device */
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#define XPS2_SRST_OFFSET 0x00000000 /* Software Reset register */
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#define XPS2_STATUS_OFFSET 0x00000004 /* Status register */
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#define XPS2_RX_DATA_OFFSET 0x00000008 /* Receive Data register */
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#define XPS2_TX_DATA_OFFSET 0x0000000C /* Transmit Data register */
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#define XPS2_GIER_OFFSET 0x0000002C /* Global Interrupt Enable reg */
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#define XPS2_IPISR_OFFSET 0x00000030 /* Interrupt Status register */
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#define XPS2_IPIER_OFFSET 0x00000038 /* Interrupt Enable register */
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/* Reset Register Bit Definitions */
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#define XPS2_SRST_RESET 0x0000000A /* Software Reset */
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/* Status Register Bit Positions */
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#define XPS2_STATUS_RX_FULL 0x00000001 /* Receive Full */
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#define XPS2_STATUS_TX_FULL 0x00000002 /* Transmit Full */
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/*
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* Bit definitions for ISR/IER registers. Both the registers have the same bit
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* definitions and are only defined once.
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*/
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#define XPS2_IPIXR_WDT_TOUT 0x00000001 /* Watchdog Timeout Interrupt */
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#define XPS2_IPIXR_TX_NOACK 0x00000002 /* Transmit No ACK Interrupt */
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#define XPS2_IPIXR_TX_ACK 0x00000004 /* Transmit ACK (Data) Interrupt */
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#define XPS2_IPIXR_RX_OVF 0x00000008 /* Receive Overflow Interrupt */
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#define XPS2_IPIXR_RX_ERR 0x00000010 /* Receive Error Interrupt */
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#define XPS2_IPIXR_RX_FULL 0x00000020 /* Receive Data Interrupt */
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/* Mask for all the Transmit Interrupts */
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#define XPS2_IPIXR_TX_ALL (XPS2_IPIXR_TX_NOACK | XPS2_IPIXR_TX_ACK)
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/* Mask for all the Receive Interrupts */
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#define XPS2_IPIXR_RX_ALL (XPS2_IPIXR_RX_OVF | XPS2_IPIXR_RX_ERR | \
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XPS2_IPIXR_RX_FULL)
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/* Mask for all the Interrupts */
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#define XPS2_IPIXR_ALL (XPS2_IPIXR_TX_ALL | XPS2_IPIXR_RX_ALL | \
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XPS2_IPIXR_WDT_TOUT)
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/* Global Interrupt Enable mask */
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#define XPS2_GIER_GIE_MASK 0x80000000
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struct xps2data {
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int irq;
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spinlock_t lock;
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void __iomem *base_address; /* virt. address of control registers */
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unsigned int flags;
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struct serio *serio; /* serio */
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struct device *dev;
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};
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/************************************/
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/* XPS PS/2 data transmission calls */
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/************************************/
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/**
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* xps2_recv() - attempts to receive a byte from the PS/2 port.
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* @drvdata: pointer to ps2 device private data structure
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* @byte: address where the read data will be copied
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*
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* If there is any data available in the PS/2 receiver, this functions reads
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* the data, otherwise it returns error.
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*/
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static int xps2_recv(struct xps2data *drvdata, u8 *byte)
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{
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u32 sr;
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int status = -1;
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/* If there is data available in the PS/2 receiver, read it */
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sr = in_be32(drvdata->base_address + XPS2_STATUS_OFFSET);
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if (sr & XPS2_STATUS_RX_FULL) {
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*byte = in_be32(drvdata->base_address + XPS2_RX_DATA_OFFSET);
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status = 0;
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}
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return status;
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}
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/*********************/
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/* Interrupt handler */
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/*********************/
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static irqreturn_t xps2_interrupt(int irq, void *dev_id)
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{
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struct xps2data *drvdata = dev_id;
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u32 intr_sr;
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u8 c;
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int status;
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/* Get the PS/2 interrupts and clear them */
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intr_sr = in_be32(drvdata->base_address + XPS2_IPISR_OFFSET);
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out_be32(drvdata->base_address + XPS2_IPISR_OFFSET, intr_sr);
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/* Check which interrupt is active */
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if (intr_sr & XPS2_IPIXR_RX_OVF)
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dev_warn(drvdata->dev, "receive overrun error\n");
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if (intr_sr & XPS2_IPIXR_RX_ERR)
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drvdata->flags |= SERIO_PARITY;
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if (intr_sr & (XPS2_IPIXR_TX_NOACK | XPS2_IPIXR_WDT_TOUT))
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drvdata->flags |= SERIO_TIMEOUT;
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if (intr_sr & XPS2_IPIXR_RX_FULL) {
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status = xps2_recv(drvdata, &c);
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/* Error, if a byte is not received */
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if (status) {
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dev_err(drvdata->dev,
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"wrong rcvd byte count (%d)\n", status);
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} else {
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serio_interrupt(drvdata->serio, c, drvdata->flags);
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drvdata->flags = 0;
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}
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}
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return IRQ_HANDLED;
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}
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/*******************/
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/* serio callbacks */
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/*******************/
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/**
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* sxps2_write() - sends a byte out through the PS/2 port.
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* @pserio: pointer to the serio structure of the PS/2 port
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* @c: data that needs to be written to the PS/2 port
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*
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* This function checks if the PS/2 transmitter is empty and sends a byte.
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* Otherwise it returns error. Transmission fails only when nothing is connected
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* to the PS/2 port. Thats why, we do not try to resend the data in case of a
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* failure.
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*/
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static int sxps2_write(struct serio *pserio, unsigned char c)
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{
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struct xps2data *drvdata = pserio->port_data;
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unsigned long flags;
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u32 sr;
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int status = -1;
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spin_lock_irqsave(&drvdata->lock, flags);
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/* If the PS/2 transmitter is empty send a byte of data */
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sr = in_be32(drvdata->base_address + XPS2_STATUS_OFFSET);
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if (!(sr & XPS2_STATUS_TX_FULL)) {
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out_be32(drvdata->base_address + XPS2_TX_DATA_OFFSET, c);
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status = 0;
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}
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spin_unlock_irqrestore(&drvdata->lock, flags);
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return status;
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}
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/**
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* sxps2_open() - called when a port is opened by the higher layer.
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* @pserio: pointer to the serio structure of the PS/2 device
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*
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* This function requests irq and enables interrupts for the PS/2 device.
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*/
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static int sxps2_open(struct serio *pserio)
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{
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struct xps2data *drvdata = pserio->port_data;
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int error;
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u8 c;
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error = request_irq(drvdata->irq, &xps2_interrupt, 0,
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DRIVER_NAME, drvdata);
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if (error) {
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dev_err(drvdata->dev,
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"Couldn't allocate interrupt %d\n", drvdata->irq);
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return error;
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}
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/* start reception by enabling the interrupts */
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out_be32(drvdata->base_address + XPS2_GIER_OFFSET, XPS2_GIER_GIE_MASK);
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out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, XPS2_IPIXR_RX_ALL);
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(void)xps2_recv(drvdata, &c);
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return 0; /* success */
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}
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/**
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* sxps2_close() - frees the interrupt.
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* @pserio: pointer to the serio structure of the PS/2 device
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*
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* This function frees the irq and disables interrupts for the PS/2 device.
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*/
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static void sxps2_close(struct serio *pserio)
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{
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struct xps2data *drvdata = pserio->port_data;
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/* Disable the PS2 interrupts */
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out_be32(drvdata->base_address + XPS2_GIER_OFFSET, 0x00);
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out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, 0x00);
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free_irq(drvdata->irq, drvdata);
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}
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/**
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* xps2_of_probe - probe method for the PS/2 device.
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* @of_dev: pointer to OF device structure
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* @match: pointer to the structure used for matching a device
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*
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* This function probes the PS/2 device in the device tree.
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* It initializes the driver data structure and the hardware.
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* It returns 0, if the driver is bound to the PS/2 device, or a negative
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* value if there is an error.
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*/
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static int xps2_of_probe(struct platform_device *ofdev)
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{
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struct resource r_mem; /* IO mem resources */
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struct xps2data *drvdata;
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struct serio *serio;
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struct device *dev = &ofdev->dev;
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resource_size_t remap_size, phys_addr;
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unsigned int irq;
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int error;
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dev_info(dev, "Device Tree Probing \'%pOFn\'\n", dev->of_node);
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/* Get iospace for the device */
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error = of_address_to_resource(dev->of_node, 0, &r_mem);
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if (error) {
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dev_err(dev, "invalid address\n");
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return error;
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}
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/* Get IRQ for the device */
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irq = irq_of_parse_and_map(dev->of_node, 0);
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if (!irq) {
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dev_err(dev, "no IRQ found\n");
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return -ENODEV;
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}
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drvdata = kzalloc(sizeof(struct xps2data), GFP_KERNEL);
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serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
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if (!drvdata || !serio) {
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error = -ENOMEM;
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goto failed1;
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}
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spin_lock_init(&drvdata->lock);
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drvdata->irq = irq;
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drvdata->serio = serio;
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drvdata->dev = dev;
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phys_addr = r_mem.start;
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remap_size = resource_size(&r_mem);
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if (!request_mem_region(phys_addr, remap_size, DRIVER_NAME)) {
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dev_err(dev, "Couldn't lock memory region at 0x%08llX\n",
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(unsigned long long)phys_addr);
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error = -EBUSY;
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goto failed1;
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}
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/* Fill in configuration data and add them to the list */
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drvdata->base_address = ioremap(phys_addr, remap_size);
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if (drvdata->base_address == NULL) {
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dev_err(dev, "Couldn't ioremap memory at 0x%08llX\n",
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(unsigned long long)phys_addr);
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error = -EFAULT;
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goto failed2;
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}
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/* Disable all the interrupts, just in case */
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out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, 0);
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/*
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* Reset the PS2 device and abort any current transaction,
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* to make sure we have the PS2 in a good state.
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*/
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out_be32(drvdata->base_address + XPS2_SRST_OFFSET, XPS2_SRST_RESET);
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dev_info(dev, "Xilinx PS2 at 0x%08llX mapped to 0x%p, irq=%d\n",
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(unsigned long long)phys_addr, drvdata->base_address,
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drvdata->irq);
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serio->id.type = SERIO_8042;
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serio->write = sxps2_write;
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serio->open = sxps2_open;
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serio->close = sxps2_close;
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serio->port_data = drvdata;
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serio->dev.parent = dev;
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snprintf(serio->name, sizeof(serio->name),
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"Xilinx XPS PS/2 at %08llX", (unsigned long long)phys_addr);
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snprintf(serio->phys, sizeof(serio->phys),
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"xilinxps2/serio at %08llX", (unsigned long long)phys_addr);
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serio_register_port(serio);
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platform_set_drvdata(ofdev, drvdata);
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return 0; /* success */
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failed2:
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release_mem_region(phys_addr, remap_size);
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failed1:
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kfree(serio);
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kfree(drvdata);
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return error;
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}
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/**
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* xps2_of_remove - unbinds the driver from the PS/2 device.
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* @of_dev: pointer to OF device structure
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*
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* This function is called if a device is physically removed from the system or
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* if the driver module is being unloaded. It frees any resources allocated to
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* the device.
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*/
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static int xps2_of_remove(struct platform_device *of_dev)
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{
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struct xps2data *drvdata = platform_get_drvdata(of_dev);
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struct resource r_mem; /* IO mem resources */
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serio_unregister_port(drvdata->serio);
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iounmap(drvdata->base_address);
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/* Get iospace of the device */
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if (of_address_to_resource(of_dev->dev.of_node, 0, &r_mem))
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dev_err(drvdata->dev, "invalid address\n");
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else
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release_mem_region(r_mem.start, resource_size(&r_mem));
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kfree(drvdata);
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return 0;
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}
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/* Match table for of_platform binding */
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static const struct of_device_id xps2_of_match[] = {
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{ .compatible = "xlnx,xps-ps2-1.00.a", },
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{ /* end of list */ },
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|
|
};
|
||
|
|
MODULE_DEVICE_TABLE(of, xps2_of_match);
|
||
|
|
|
||
|
|
static struct platform_driver xps2_of_driver = {
|
||
|
|
.driver = {
|
||
|
|
.name = DRIVER_NAME,
|
||
|
|
.of_match_table = xps2_of_match,
|
||
|
|
},
|
||
|
|
.probe = xps2_of_probe,
|
||
|
|
.remove = xps2_of_remove,
|
||
|
|
};
|
||
|
|
module_platform_driver(xps2_of_driver);
|
||
|
|
|
||
|
|
MODULE_AUTHOR("Xilinx, Inc.");
|
||
|
|
MODULE_DESCRIPTION("Xilinx XPS PS/2 driver");
|
||
|
|
MODULE_LICENSE("GPL");
|
||
|
|
|