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371 lines
10 KiB
371 lines
10 KiB
// 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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}; |
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MODULE_DEVICE_TABLE(of, xps2_of_match); |
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static struct platform_driver xps2_of_driver = { |
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.driver = { |
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.name = DRIVER_NAME, |
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.of_match_table = xps2_of_match, |
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}, |
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.probe = xps2_of_probe, |
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.remove = xps2_of_remove, |
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}; |
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module_platform_driver(xps2_of_driver); |
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MODULE_AUTHOR("Xilinx, Inc."); |
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MODULE_DESCRIPTION("Xilinx XPS PS/2 driver"); |
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MODULE_LICENSE("GPL"); |
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