drivers/input/serio/arc_ps2.c

   1 /*
   2  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * Driver is originally developed by Pavel Sokolov <psokolov@synopsys.com>
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/input.h>
  14 #include <linux/serio.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/io.h>
  17 #include <linux/kernel.h>
  18 #include <linux/slab.h>
  19
  20 #define ARC_PS2_PORTS                   2
  21
  22 #define ARC_ARC_PS2_ID                  0x0001f609
  23
  24 #define STAT_TIMEOUT                    128
  25
  26 #define PS2_STAT_RX_FRM_ERR             (1)
  27 #define PS2_STAT_RX_BUF_OVER            (1 << 1)
  28 #define PS2_STAT_RX_INT_EN              (1 << 2)
  29 #define PS2_STAT_RX_VAL                 (1 << 3)
  30 #define PS2_STAT_TX_ISNOT_FUL           (1 << 4)
  31 #define PS2_STAT_TX_INT_EN              (1 << 5)
  32
  33 struct arc_ps2_port {
  34         void __iomem *data_addr;
  35         void __iomem *status_addr;
  36         struct serio *io;
  37 };
  38
  39 struct arc_ps2_data {
  40         struct arc_ps2_port port[ARC_PS2_PORTS];
  41         void __iomem *addr;
  42         unsigned int frame_error;
  43         unsigned int buf_overflow;
  44         unsigned int total_int;
  45 };
  46
  47 static void arc_ps2_check_rx(struct arc_ps2_data *arc_ps2,
  48                              struct arc_ps2_port *port)
  49 {
  50         unsigned int timeout = 1000;
  51         unsigned int flag, status;
  52         unsigned char data;
  53
  54         do {
  55                 status = ioread32(port->status_addr);
  56                 if (!(status & PS2_STAT_RX_VAL))
  57                         return;
  58
  59                 data = ioread32(port->data_addr) & 0xff;
  60
  61                 flag = 0;
  62                 arc_ps2->total_int++;
  63                 if (status & PS2_STAT_RX_FRM_ERR) {
  64                         arc_ps2->frame_error++;
  65                         flag |= SERIO_PARITY;
  66                 } else if (status & PS2_STAT_RX_BUF_OVER) {
  67                         arc_ps2->buf_overflow++;
  68                         flag |= SERIO_FRAME;
  69                 }
  70
  71                 serio_interrupt(port->io, data, flag);
  72         } while (--timeout);
  73
  74         dev_err(&port->io->dev, "PS/2 hardware stuck\n");
  75 }
  76
  77 static irqreturn_t arc_ps2_interrupt(int irq, void *dev)
  78 {
  79         struct arc_ps2_data *arc_ps2 = dev;
  80         int i;
  81
  82         for (i = 0; i < ARC_PS2_PORTS; i++)
  83                 arc_ps2_check_rx(arc_ps2, &arc_ps2->port[i]);
  84
  85         return IRQ_HANDLED;
  86 }
  87
  88 static int arc_ps2_write(struct serio *io, unsigned char val)
  89 {
  90         unsigned status;
  91         struct arc_ps2_port *port = io->port_data;
  92         int timeout = STAT_TIMEOUT;
  93
  94         do {
  95                 status = ioread32(port->status_addr);
  96                 cpu_relax();
  97
  98                 if (status & PS2_STAT_TX_ISNOT_FUL) {
  99                         iowrite32(val & 0xff, port->data_addr);
 100                         return 0;
 101                 }
 102
 103         } while (--timeout);
 104
 105         dev_err(&io->dev, "write timeout\n");
 106         return -ETIMEDOUT;
 107 }
 108
 109 static int arc_ps2_open(struct serio *io)
 110 {
 111         struct arc_ps2_port *port = io->port_data;
 112
 113         iowrite32(PS2_STAT_RX_INT_EN, port->status_addr);
 114
 115         return 0;
 116 }
 117
 118 static void arc_ps2_close(struct serio *io)
 119 {
 120         struct arc_ps2_port *port = io->port_data;
 121
 122         iowrite32(ioread32(port->status_addr) & ~PS2_STAT_RX_INT_EN,
 123                   port->status_addr);
 124 }
 125
 126 static void __iomem *arc_ps2_calc_addr(struct arc_ps2_data *arc_ps2,
 127                                                   int index, bool status)
 128 {
 129         void __iomem *addr;
 130
 131         addr = arc_ps2->addr + 4 + 4 * index;
 132         if (status)
 133                 addr += ARC_PS2_PORTS * 4;
 134
 135         return addr;
 136 }
 137
 138 static void arc_ps2_inhibit_ports(struct arc_ps2_data *arc_ps2)
 139 {
 140         void __iomem *addr;
 141         u32 val;
 142         int i;
 143
 144         for (i = 0; i < ARC_PS2_PORTS; i++) {
 145                 addr = arc_ps2_calc_addr(arc_ps2, i, true);
 146                 val = ioread32(addr);
 147                 val &= ~(PS2_STAT_RX_INT_EN | PS2_STAT_TX_INT_EN);
 148                 iowrite32(val, addr);
 149         }
 150 }
 151
 152 static int arc_ps2_create_port(struct platform_device *pdev,
 153                                          struct arc_ps2_data *arc_ps2,
 154                                          int index)
 155 {
 156         struct arc_ps2_port *port = &arc_ps2->port[index];
 157         struct serio *io;
 158
 159         io = kzalloc(sizeof(struct serio), GFP_KERNEL);
 160         if (!io)
 161                 return -ENOMEM;
 162
 163         io->id.type = SERIO_8042;
 164         io->write = arc_ps2_write;
 165         io->open = arc_ps2_open;
 166         io->close = arc_ps2_close;
 167         snprintf(io->name, sizeof(io->name), "ARC PS/2 port%d", index);
 168         snprintf(io->phys, sizeof(io->phys), "arc/serio%d", index);
 169         io->port_data = port;
 170
 171         port->io = io;
 172
 173         port->data_addr = arc_ps2_calc_addr(arc_ps2, index, false);
 174         port->status_addr = arc_ps2_calc_addr(arc_ps2, index, true);
 175
 176         dev_dbg(&pdev->dev, "port%d is allocated (data = 0x%p, status = 0x%p)\n",
 177                 index, port->data_addr, port->status_addr);
 178
 179         serio_register_port(port->io);
 180         return 0;
 181 }
 182
 183 static int arc_ps2_probe(struct platform_device *pdev)
 184 {
 185         struct arc_ps2_data *arc_ps2;
 186         struct resource *res;
 187         int irq;
 188         int error, id, i;
 189
 190         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 191         if (!res) {
 192                 dev_err(&pdev->dev, "no IO memory defined\n");
 193                 return -EINVAL;
 194         }
 195
 196         irq = platform_get_irq_byname(pdev, "arc_ps2_irq");
 197         if (irq < 0) {
 198                 dev_err(&pdev->dev, "no IRQ defined\n");
 199                 return -EINVAL;
 200         }
 201
 202         arc_ps2 = devm_kzalloc(&pdev->dev, sizeof(struct arc_ps2_data),
 203                                 GFP_KERNEL);
 204         if (!arc_ps2) {
 205                 dev_err(&pdev->dev, "out of memory\n");
 206                 return -ENOMEM;
 207         }
 208
 209         arc_ps2->addr = devm_request_and_ioremap(&pdev->dev, res);
 210         if (!arc_ps2->addr)
 211                 return -EBUSY;
 212
 213         dev_info(&pdev->dev, "irq = %d, address = 0x%p, ports = %i\n",
 214                  irq, arc_ps2->addr, ARC_PS2_PORTS);
 215
 216         id = ioread32(arc_ps2->addr);
 217         if (id != ARC_ARC_PS2_ID) {
 218                 dev_err(&pdev->dev, "device id does not match\n");
 219                 return -ENXIO;
 220         }
 221
 222         arc_ps2_inhibit_ports(arc_ps2);
 223
 224         error = devm_request_irq(&pdev->dev, irq, arc_ps2_interrupt,
 225                                  0, "arc_ps2", arc_ps2);
 226         if (error) {
 227                 dev_err(&pdev->dev, "Could not allocate IRQ\n");
 228                 return error;
 229         }
 230
 231         for (i = 0; i < ARC_PS2_PORTS; i++) {
 232                 error = arc_ps2_create_port(pdev, arc_ps2, i);
 233                 if (error) {
 234                         while (--i >= 0)
 235                                 serio_unregister_port(arc_ps2->port[i].io);
 236                         return error;
 237                 }
 238         }
 239
 240         platform_set_drvdata(pdev, arc_ps2);
 241
 242         return 0;
 243 }
 244
 245 static int __devexit arc_ps2_remove(struct platform_device *pdev)
 246 {
 247         struct arc_ps2_data *arc_ps2 = platform_get_drvdata(pdev);
 248         int i;
 249
 250         for (i = 0; i < ARC_PS2_PORTS; i++)
 251                 serio_unregister_port(arc_ps2->port[i].io);
 252
 253         dev_dbg(&pdev->dev, "interrupt count = %i\n", arc_ps2->total_int);
 254         dev_dbg(&pdev->dev, "frame error count = %i\n", arc_ps2->frame_error);
 255         dev_dbg(&pdev->dev, "buffer overflow count = %i\n",
 256                 arc_ps2->buf_overflow);
 257
 258         return 0;
 259 }
 260
 261 static struct platform_driver arc_ps2_driver = {
 262         .driver = {
 263                 .name   = "arc_ps2",
 264                 .owner  = THIS_MODULE,
 265         },
 266         .probe  = arc_ps2_probe,
 267         .remove = arc_ps2_remove,
 268 };
 269
 270 module_platform_driver(arc_ps2_driver);
 271
 272 MODULE_LICENSE("GPL");
 273 MODULE_AUTHOR("Pavel Sokolov <psokolov@synopsys.com>");
 274 MODULE_DESCRIPTION("ARC PS/2 Driver");