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_prepare_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_unprepare(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_unprepare(kmi->clk); 108 } 109 110 static int amba_kmi_probe(struct amba_device *dev, 111 const struct amba_id *id) 112 { 113 struct amba_kmi_port *kmi; 114 struct serio *io; 115 int ret; 116 117 ret = amba_request_regions(dev, NULL); 118 if (ret) 119 return ret; 120 121 kmi = kzalloc(sizeof(struct amba_kmi_port), GFP_KERNEL); 122 io = kzalloc(sizeof(struct serio), GFP_KERNEL); 123 if (!kmi || !io) { 124 ret = -ENOMEM; 125 goto out; 126 } 127 128 129 io->id.type = SERIO_8042; 130 io->write = amba_kmi_write; 131 io->open = amba_kmi_open; 132 io->close = amba_kmi_close; 133 strlcpy(io->name, dev_name(&dev->dev), sizeof(io->name)); 134 strlcpy(io->phys, dev_name(&dev->dev), sizeof(io->phys)); 135 io->port_data = kmi; 136 io->dev.parent = &dev->dev; 137 138 kmi->io = io; 139 kmi->base = ioremap(dev->res.start, resource_size(&dev->res)); 140 if (!kmi->base) { 141 ret = -ENOMEM; 142 goto out; 143 } 144 145 kmi->clk = clk_get(&dev->dev, "KMIREFCLK"); 146 if (IS_ERR(kmi->clk)) { 147 ret = PTR_ERR(kmi->clk); 148 goto unmap; 149 } 150 151 kmi->irq = dev->irq[0]; 152 amba_set_drvdata(dev, kmi); 153 154 serio_register_port(kmi->io); 155 return 0; 156 157 unmap: 158 iounmap(kmi->base); 159 out: 160 kfree(kmi); 161 kfree(io); 162 amba_release_regions(dev); 163 return ret; 164 } 165 166 static int amba_kmi_remove(struct amba_device *dev) 167 { 168 struct amba_kmi_port *kmi = amba_get_drvdata(dev); 169 170 amba_set_drvdata(dev, NULL); 171 172 serio_unregister_port(kmi->io); 173 clk_put(kmi->clk); 174 iounmap(kmi->base); 175 kfree(kmi); 176 amba_release_regions(dev); 177 return 0; 178 } 179 180 static int amba_kmi_resume(struct amba_device *dev) 181 { 182 struct amba_kmi_port *kmi = amba_get_drvdata(dev); 183 184 /* kick the serio layer to rescan this port */ 185 serio_reconnect(kmi->io); 186 187 return 0; 188 } 189 190 static struct amba_id amba_kmi_idtable[] = { 191 { 192 .id = 0x00041050, 193 .mask = 0x000fffff, 194 }, 195 { 0, 0 } 196 }; 197 198 MODULE_DEVICE_TABLE(amba, amba_kmi_idtable); 199 200 static struct amba_driver ambakmi_driver = { 201 .drv = { 202 .name = "kmi-pl050", 203 .owner = THIS_MODULE, 204 }, 205 .id_table = amba_kmi_idtable, 206 .probe = amba_kmi_probe, 207 .remove = amba_kmi_remove, 208 .resume = amba_kmi_resume, 209 }; 210 211 module_amba_driver(ambakmi_driver); 212 213 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); 214 MODULE_DESCRIPTION("AMBA KMI controller driver"); 215 MODULE_LICENSE("GPL"); 216