drivers/input/serio/arc_ps2.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
   4  *
   5  * Driver is originally developed by Pavel Sokolov <psokolov@synopsys.com>
   6  */
   7
   8 #include <linux/err.h>
   9 #include <linux/module.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/input.h>
  12 #include <linux/serio.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/of.h>
  15 #include <linux/io.h>
  16 #include <linux/kernel.h>
  17 #include <linux/slab.h>
  18
  19 #define ARC_PS2_PORTS                   2
  20
  21 #define ARC_ARC_PS2_ID                  0x0001f609
  22
  23 #define STAT_TIMEOUT                    128
  24
  25 #define PS2_STAT_RX_FRM_ERR             (1)
  26 #define PS2_STAT_RX_BUF_OVER            (1 << 1)
  27 #define PS2_STAT_RX_INT_EN              (1 << 2)
  28 #define PS2_STAT_RX_VAL                 (1 << 3)
  29 #define PS2_STAT_TX_ISNOT_FUL           (1 << 4)
  30 #define PS2_STAT_TX_INT_EN              (1 << 5)
  31
  32 struct arc_ps2_port {
  33         void __iomem *data_addr;
  34         void __iomem *status_addr;
  35         struct serio *io;
  36 };
  37
  38 struct arc_ps2_data {
  39         struct arc_ps2_port port[ARC_PS2_PORTS];
  40         void __iomem *addr;
  41         unsigned int frame_error;
  42         unsigned int buf_overflow;
  43         unsigned int total_int;
  44 };
  45
  46 static void arc_ps2_check_rx(struct arc_ps2_data *arc_ps2,
  47                              struct arc_ps2_port *port)
  48 {
  49         unsigned int timeout = 1000;
  50         unsigned int flag, status;
  51         unsigned char data;
  52
  53         do {
  54                 status = ioread32(port->status_addr);
  55                 if (!(status & PS2_STAT_RX_VAL))
  56                         return;
  57
  58                 data = ioread32(port->data_addr) & 0xff;
  59
  60                 flag = 0;
  61                 arc_ps2->total_int++;
  62                 if (status & PS2_STAT_RX_FRM_ERR) {
  63                         arc_ps2->frame_error++;
  64                         flag |= SERIO_PARITY;
  65                 } else if (status & PS2_STAT_RX_BUF_OVER) {
  66                         arc_ps2->buf_overflow++;
  67                         flag |= SERIO_FRAME;
  68                 }
  69
  70                 serio_interrupt(port->io, data, flag);
  71         } while (--timeout);
  72
  73         dev_err(&port->io->dev, "PS/2 hardware stuck\n");
  74 }
  75
  76 static irqreturn_t arc_ps2_interrupt(int irq, void *dev)
  77 {
  78         struct arc_ps2_data *arc_ps2 = dev;
  79         int i;
  80
  81         for (i = 0; i < ARC_PS2_PORTS; i++)
  82                 arc_ps2_check_rx(arc_ps2, &arc_ps2->port[i]);
  83
  84         return IRQ_HANDLED;
  85 }
  86
  87 static int arc_ps2_write(struct serio *io, unsigned char val)
  88 {
  89         unsigned status;
  90         struct arc_ps2_port *port = io->port_data;
  91         int timeout = STAT_TIMEOUT;
  92
  93         do {
  94                 status = ioread32(port->status_addr);
  95                 cpu_relax();
  96
  97                 if (status & PS2_STAT_TX_ISNOT_FUL) {
  98                         iowrite32(val & 0xff, port->data_addr);
  99                         return 0;
 100                 }
 101
 102         } while (--timeout);
 103
 104         dev_err(&io->dev, "write timeout\n");
 105         return -ETIMEDOUT;
 106 }
 107
 108 static int arc_ps2_open(struct serio *io)
 109 {
 110         struct arc_ps2_port *port = io->port_data;
 111
 112         iowrite32(PS2_STAT_RX_INT_EN, port->status_addr);
 113
 114         return 0;
 115 }
 116
 117 static void arc_ps2_close(struct serio *io)
 118 {
 119         struct arc_ps2_port *port = io->port_data;
 120
 121         iowrite32(ioread32(port->status_addr) & ~PS2_STAT_RX_INT_EN,
 122                   port->status_addr);
 123 }
 124
 125 static void __iomem *arc_ps2_calc_addr(struct arc_ps2_data *arc_ps2,
 126                                                   int index, bool status)
 127 {
 128         void __iomem *addr;
 129
 130         addr = arc_ps2->addr + 4 + 4 * index;
 131         if (status)
 132                 addr += ARC_PS2_PORTS * 4;
 133
 134         return addr;
 135 }
 136
 137 static void arc_ps2_inhibit_ports(struct arc_ps2_data *arc_ps2)
 138 {
 139         void __iomem *addr;
 140         u32 val;
 141         int i;
 142
 143         for (i = 0; i < ARC_PS2_PORTS; i++) {
 144                 addr = arc_ps2_calc_addr(arc_ps2, i, true);
 145                 val = ioread32(addr);
 146                 val &= ~(PS2_STAT_RX_INT_EN | PS2_STAT_TX_INT_EN);
 147                 iowrite32(val, addr);
 148         }
 149 }
 150
 151 static int arc_ps2_create_port(struct platform_device *pdev,
 152                                          struct arc_ps2_data *arc_ps2,
 153                                          int index)
 154 {
 155         struct arc_ps2_port *port = &arc_ps2->port[index];
 156         struct serio *io;
 157
 158         io = kzalloc(sizeof(struct serio), GFP_KERNEL);
 159         if (!io)
 160                 return -ENOMEM;
 161
 162         io->id.type = SERIO_8042;
 163         io->write = arc_ps2_write;
 164         io->open = arc_ps2_open;
 165         io->close = arc_ps2_close;
 166         snprintf(io->name, sizeof(io->name), "ARC PS/2 port%d", index);
 167         snprintf(io->phys, sizeof(io->phys), "arc/serio%d", index);
 168         io->port_data = port;
 169
 170         port->io = io;
 171
 172         port->data_addr = arc_ps2_calc_addr(arc_ps2, index, false);
 173         port->status_addr = arc_ps2_calc_addr(arc_ps2, index, true);
 174
 175         dev_dbg(&pdev->dev, "port%d is allocated (data = 0x%p, status = 0x%p)\n",
 176                 index, port->data_addr, port->status_addr);
 177
 178         serio_register_port(port->io);
 179         return 0;
 180 }
 181
 182 static int arc_ps2_probe(struct platform_device *pdev)
 183 {
 184         struct arc_ps2_data *arc_ps2;
 185         struct resource *res;
 186         int irq;
 187         int error, id, i;
 188
 189         irq = platform_get_irq_byname(pdev, "arc_ps2_irq");
 190         if (irq < 0) {
 191                 dev_err(&pdev->dev, "no IRQ defined\n");
 192                 return -EINVAL;
 193         }
 194
 195         arc_ps2 = devm_kzalloc(&pdev->dev, sizeof(struct arc_ps2_data),
 196                                 GFP_KERNEL);
 197         if (!arc_ps2) {
 198                 dev_err(&pdev->dev, "out of memory\n");
 199                 return -ENOMEM;
 200         }
 201
 202         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 203         arc_ps2->addr = devm_ioremap_resource(&pdev->dev, res);
 204         if (IS_ERR(arc_ps2->addr))
 205                 return PTR_ERR(arc_ps2->addr);
 206
 207         dev_info(&pdev->dev, "irq = %d, address = 0x%p, ports = %i\n",
 208                  irq, arc_ps2->addr, ARC_PS2_PORTS);
 209
 210         id = ioread32(arc_ps2->addr);
 211         if (id != ARC_ARC_PS2_ID) {
 212                 dev_err(&pdev->dev, "device id does not match\n");
 213                 return -ENXIO;
 214         }
 215
 216         arc_ps2_inhibit_ports(arc_ps2);
 217
 218         error = devm_request_irq(&pdev->dev, irq, arc_ps2_interrupt,
 219                                  0, "arc_ps2", arc_ps2);
 220         if (error) {
 221                 dev_err(&pdev->dev, "Could not allocate IRQ\n");
 222                 return error;
 223         }
 224
 225         for (i = 0; i < ARC_PS2_PORTS; i++) {
 226                 error = arc_ps2_create_port(pdev, arc_ps2, i);
 227                 if (error) {
 228                         while (--i >= 0)
 229                                 serio_unregister_port(arc_ps2->port[i].io);
 230                         return error;
 231                 }
 232         }
 233
 234         platform_set_drvdata(pdev, arc_ps2);
 235
 236         return 0;
 237 }
 238
 239 static int arc_ps2_remove(struct platform_device *pdev)
 240 {
 241         struct arc_ps2_data *arc_ps2 = platform_get_drvdata(pdev);
 242         int i;
 243
 244         for (i = 0; i < ARC_PS2_PORTS; i++)
 245                 serio_unregister_port(arc_ps2->port[i].io);
 246
 247         dev_dbg(&pdev->dev, "interrupt count = %i\n", arc_ps2->total_int);
 248         dev_dbg(&pdev->dev, "frame error count = %i\n", arc_ps2->frame_error);
 249         dev_dbg(&pdev->dev, "buffer overflow count = %i\n",
 250                 arc_ps2->buf_overflow);
 251
 252         return 0;
 253 }
 254
 255 #ifdef CONFIG_OF
 256 static const struct of_device_id arc_ps2_match[] = {
 257         { .compatible = "snps,arc_ps2" },
 258         { },
 259 };
 260 MODULE_DEVICE_TABLE(of, arc_ps2_match);
 261 #endif
 262
 263 static struct platform_driver arc_ps2_driver = {
 264         .driver = {
 265                 .name           = "arc_ps2",
 266                 .of_match_table = of_match_ptr(arc_ps2_match),
 267         },
 268         .probe  = arc_ps2_probe,
 269         .remove = arc_ps2_remove,
 270 };
 271
 272 module_platform_driver(arc_ps2_driver);
 273
 274 MODULE_LICENSE("GPL");
 275 MODULE_AUTHOR("Pavel Sokolov <psokolov@synopsys.com>");
 276 MODULE_DESCRIPTION("ARC PS/2 Driver");