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 #include <linux/amba/bus.h> 23 #include <linux/amba/kmi.h> 24 #include <linux/clk.h> 25 26 #include <asm/io.h> 27 #include <asm/irq.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) 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); 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_enable(kmi->clk); 76 if (ret) 77 goto out; 78 79 divisor = clk_get_rate(kmi->clk) / 8000000 - 1; 80 writeb(divisor, KMICLKDIV); 81 writeb(KMICR_EN, KMICR); 82 83 ret = request_irq(kmi->irq, amba_kmi_int, 0, "kmi-pl050", kmi); 84 if (ret) { 85 printk(KERN_ERR "kmi: failed to claim IRQ%d\n", kmi->irq); 86 writeb(0, KMICR); 87 goto clk_disable; 88 } 89 90 writeb(KMICR_EN | KMICR_RXINTREN, KMICR); 91 92 return 0; 93 94 clk_disable: 95 clk_disable(kmi->clk); 96 out: 97 return ret; 98 } 99 100 static void amba_kmi_close(struct serio *io) 101 { 102 struct amba_kmi_port *kmi = io->port_data; 103 104 writeb(0, KMICR); 105 106 free_irq(kmi->irq, kmi); 107 clk_disable(kmi->clk); 108 } 109 110 static int amba_kmi_probe(struct amba_device *dev, void *id) 111 { 112 struct amba_kmi_port *kmi; 113 struct serio *io; 114 int ret; 115 116 ret = amba_request_regions(dev, NULL); 117 if (ret) 118 return ret; 119 120 kmi = kmalloc(sizeof(struct amba_kmi_port), GFP_KERNEL); 121 io = kmalloc(sizeof(struct serio), GFP_KERNEL); 122 if (!kmi || !io) { 123 ret = -ENOMEM; 124 goto out; 125 } 126 127 memset(kmi, 0, sizeof(struct amba_kmi_port)); 128 memset(io, 0, sizeof(struct serio)); 129 130 io->id.type = SERIO_8042; 131 io->write = amba_kmi_write; 132 io->open = amba_kmi_open; 133 io->close = amba_kmi_close; 134 strlcpy(io->name, dev->dev.bus_id, sizeof(io->name)); 135 strlcpy(io->phys, dev->dev.bus_id, sizeof(io->phys)); 136 io->port_data = kmi; 137 io->dev.parent = &dev->dev; 138 139 kmi->io = io; 140 kmi->base = ioremap(dev->res.start, KMI_SIZE); 141 if (!kmi->base) { 142 ret = -ENOMEM; 143 goto out; 144 } 145 146 kmi->clk = clk_get(&dev->dev, "KMIREFCLK"); 147 if (IS_ERR(kmi->clk)) { 148 ret = PTR_ERR(kmi->clk); 149 goto unmap; 150 } 151 152 kmi->irq = dev->irq[0]; 153 amba_set_drvdata(dev, kmi); 154 155 serio_register_port(kmi->io); 156 return 0; 157 158 unmap: 159 iounmap(kmi->base); 160 out: 161 kfree(kmi); 162 kfree(io); 163 amba_release_regions(dev); 164 return ret; 165 } 166 167 static int amba_kmi_remove(struct amba_device *dev) 168 { 169 struct amba_kmi_port *kmi = amba_get_drvdata(dev); 170 171 amba_set_drvdata(dev, NULL); 172 173 serio_unregister_port(kmi->io); 174 clk_put(kmi->clk); 175 iounmap(kmi->base); 176 kfree(kmi); 177 amba_release_regions(dev); 178 return 0; 179 } 180 181 static int amba_kmi_resume(struct amba_device *dev) 182 { 183 struct amba_kmi_port *kmi = amba_get_drvdata(dev); 184 185 /* kick the serio layer to rescan this port */ 186 serio_reconnect(kmi->io); 187 188 return 0; 189 } 190 191 static struct amba_id amba_kmi_idtable[] = { 192 { 193 .id = 0x00041050, 194 .mask = 0x000fffff, 195 }, 196 { 0, 0 } 197 }; 198 199 static struct amba_driver ambakmi_driver = { 200 .drv = { 201 .name = "kmi-pl050", 202 }, 203 .id_table = amba_kmi_idtable, 204 .probe = amba_kmi_probe, 205 .remove = amba_kmi_remove, 206 .resume = amba_kmi_resume, 207 }; 208 209 static int __init amba_kmi_init(void) 210 { 211 return amba_driver_register(&ambakmi_driver); 212 } 213 214 static void __exit amba_kmi_exit(void) 215 { 216 amba_driver_unregister(&ambakmi_driver); 217 } 218 219 module_init(amba_kmi_init); 220 module_exit(amba_kmi_exit); 221 222 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); 223 MODULE_DESCRIPTION("AMBA KMI controller driver"); 224 MODULE_LICENSE("GPL"); 225