1 /* 2 * linux/drivers/input/serio/ambakmi.c 3 * 4 * Copyright (C) 2000-2003 Deep Blue Solutions Ltd. 5 * Copyright (C) 2002 Russell King. 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 */ 12 #include <linux/module.h> 13 #include <linux/init.h> 14 #include <linux/serio.h> 15 #include <linux/errno.h> 16 #include <linux/interrupt.h> 17 #include <linux/ioport.h> 18 #include <linux/device.h> 19 #include <linux/delay.h> 20 #include <linux/slab.h> 21 #include <linux/err.h> 22 23 #include <asm/io.h> 24 #include <asm/irq.h> 25 #include <asm/hardware/amba.h> 26 #include <asm/hardware/amba_kmi.h> 27 #include <asm/hardware/clock.h> 28 29 #define KMI_BASE (kmi->base) 30 31 struct amba_kmi_port { 32 struct serio *io; 33 struct clk *clk; 34 void __iomem *base; 35 unsigned int irq; 36 unsigned int divisor; 37 unsigned int open; 38 }; 39 40 static irqreturn_t amba_kmi_int(int irq, void *dev_id, struct pt_regs *regs) 41 { 42 struct amba_kmi_port *kmi = dev_id; 43 unsigned int status = readb(KMIIR); 44 int handled = IRQ_NONE; 45 46 while (status & KMIIR_RXINTR) { 47 serio_interrupt(kmi->io, readb(KMIDATA), 0, regs); 48 status = readb(KMIIR); 49 handled = IRQ_HANDLED; 50 } 51 52 return handled; 53 } 54 55 static int amba_kmi_write(struct serio *io, unsigned char val) 56 { 57 struct amba_kmi_port *kmi = io->port_data; 58 unsigned int timeleft = 10000; /* timeout in 100ms */ 59 60 while ((readb(KMISTAT) & KMISTAT_TXEMPTY) == 0 && timeleft--) 61 udelay(10); 62 63 if (timeleft) 64 writeb(val, KMIDATA); 65 66 return timeleft ? 0 : SERIO_TIMEOUT; 67 } 68 69 static int amba_kmi_open(struct serio *io) 70 { 71 struct amba_kmi_port *kmi = io->port_data; 72 unsigned int divisor; 73 int ret; 74 75 ret = clk_use(kmi->clk); 76 if (ret) 77 goto out; 78 79 ret = clk_enable(kmi->clk); 80 if (ret) 81 goto clk_unuse; 82 83 divisor = clk_get_rate(kmi->clk) / 8000000 - 1; 84 writeb(divisor, KMICLKDIV); 85 writeb(KMICR_EN, KMICR); 86 87 ret = request_irq(kmi->irq, amba_kmi_int, 0, "kmi-pl050", kmi); 88 if (ret) { 89 printk(KERN_ERR "kmi: failed to claim IRQ%d\n", kmi->irq); 90 writeb(0, KMICR); 91 goto clk_disable; 92 } 93 94 writeb(KMICR_EN | KMICR_RXINTREN, KMICR); 95 96 return 0; 97 98 clk_disable: 99 clk_disable(kmi->clk); 100 clk_unuse: 101 clk_unuse(kmi->clk); 102 out: 103 return ret; 104 } 105 106 static void amba_kmi_close(struct serio *io) 107 { 108 struct amba_kmi_port *kmi = io->port_data; 109 110 writeb(0, KMICR); 111 112 free_irq(kmi->irq, kmi); 113 clk_disable(kmi->clk); 114 clk_unuse(kmi->clk); 115 } 116 117 static int amba_kmi_probe(struct amba_device *dev, void *id) 118 { 119 struct amba_kmi_port *kmi; 120 struct serio *io; 121 int ret; 122 123 ret = amba_request_regions(dev, NULL); 124 if (ret) 125 return ret; 126 127 kmi = kmalloc(sizeof(struct amba_kmi_port), GFP_KERNEL); 128 io = kmalloc(sizeof(struct serio), GFP_KERNEL); 129 if (!kmi || !io) { 130 ret = -ENOMEM; 131 goto out; 132 } 133 134 memset(kmi, 0, sizeof(struct amba_kmi_port)); 135 memset(io, 0, sizeof(struct serio)); 136 137 io->id.type = SERIO_8042; 138 io->write = amba_kmi_write; 139 io->open = amba_kmi_open; 140 io->close = amba_kmi_close; 141 strlcpy(io->name, dev->dev.bus_id, sizeof(io->name)); 142 strlcpy(io->phys, dev->dev.bus_id, sizeof(io->phys)); 143 io->port_data = kmi; 144 io->dev.parent = &dev->dev; 145 146 kmi->io = io; 147 kmi->base = ioremap(dev->res.start, KMI_SIZE); 148 if (!kmi->base) { 149 ret = -ENOMEM; 150 goto out; 151 } 152 153 kmi->clk = clk_get(&dev->dev, "KMIREFCLK"); 154 if (IS_ERR(kmi->clk)) { 155 ret = PTR_ERR(kmi->clk); 156 goto unmap; 157 } 158 159 kmi->irq = dev->irq[0]; 160 amba_set_drvdata(dev, kmi); 161 162 serio_register_port(kmi->io); 163 return 0; 164 165 unmap: 166 iounmap(kmi->base); 167 out: 168 kfree(kmi); 169 kfree(io); 170 amba_release_regions(dev); 171 return ret; 172 } 173 174 static int amba_kmi_remove(struct amba_device *dev) 175 { 176 struct amba_kmi_port *kmi = amba_get_drvdata(dev); 177 178 amba_set_drvdata(dev, NULL); 179 180 serio_unregister_port(kmi->io); 181 clk_put(kmi->clk); 182 iounmap(kmi->base); 183 kfree(kmi); 184 amba_release_regions(dev); 185 return 0; 186 } 187 188 static int amba_kmi_resume(struct amba_device *dev) 189 { 190 struct amba_kmi_port *kmi = amba_get_drvdata(dev); 191 192 /* kick the serio layer to rescan this port */ 193 serio_reconnect(kmi->io); 194 195 return 0; 196 } 197 198 static struct amba_id amba_kmi_idtable[] = { 199 { 200 .id = 0x00041050, 201 .mask = 0x000fffff, 202 }, 203 { 0, 0 } 204 }; 205 206 static struct amba_driver ambakmi_driver = { 207 .drv = { 208 .name = "kmi-pl050", 209 }, 210 .id_table = amba_kmi_idtable, 211 .probe = amba_kmi_probe, 212 .remove = amba_kmi_remove, 213 .resume = amba_kmi_resume, 214 }; 215 216 static int __init amba_kmi_init(void) 217 { 218 return amba_driver_register(&ambakmi_driver); 219 } 220 221 static void __exit amba_kmi_exit(void) 222 { 223 amba_driver_unregister(&ambakmi_driver); 224 } 225 226 module_init(amba_kmi_init); 227 module_exit(amba_kmi_exit); 228 229 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); 230 MODULE_DESCRIPTION("AMBA KMI controller driver"); 231 MODULE_LICENSE("GPL"); 232