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/serio.h> 14 #include <linux/errno.h> 15 #include <linux/interrupt.h> 16 #include <linux/ioport.h> 17 #include <linux/device.h> 18 #include <linux/delay.h> 19 #include <linux/slab.h> 20 #include <linux/err.h> 21 #include <linux/amba/bus.h> 22 #include <linux/amba/kmi.h> 23 #include <linux/clk.h> 24 25 #include <asm/io.h> 26 #include <asm/irq.h> 27 28 #define KMI_BASE (kmi->base) 29 30 struct amba_kmi_port { 31 struct serio *io; 32 struct clk *clk; 33 void __iomem *base; 34 unsigned int irq; 35 unsigned int divisor; 36 unsigned int open; 37 }; 38 39 static irqreturn_t amba_kmi_int(int irq, void *dev_id) 40 { 41 struct amba_kmi_port *kmi = dev_id; 42 unsigned int status = readb(KMIIR); 43 int handled = IRQ_NONE; 44 45 while (status & KMIIR_RXINTR) { 46 serio_interrupt(kmi->io, readb(KMIDATA), 0); 47 status = readb(KMIIR); 48 handled = IRQ_HANDLED; 49 } 50 51 return handled; 52 } 53 54 static int amba_kmi_write(struct serio *io, unsigned char val) 55 { 56 struct amba_kmi_port *kmi = io->port_data; 57 unsigned int timeleft = 10000; /* timeout in 100ms */ 58 59 while ((readb(KMISTAT) & KMISTAT_TXEMPTY) == 0 && --timeleft) 60 udelay(10); 61 62 if (timeleft) 63 writeb(val, KMIDATA); 64 65 return timeleft ? 0 : SERIO_TIMEOUT; 66 } 67 68 static int amba_kmi_open(struct serio *io) 69 { 70 struct amba_kmi_port *kmi = io->port_data; 71 unsigned int divisor; 72 int ret; 73 74 ret = clk_prepare_enable(kmi->clk); 75 if (ret) 76 goto out; 77 78 divisor = clk_get_rate(kmi->clk) / 8000000 - 1; 79 writeb(divisor, KMICLKDIV); 80 writeb(KMICR_EN, KMICR); 81 82 ret = request_irq(kmi->irq, amba_kmi_int, IRQF_SHARED, "kmi-pl050", 83 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 serio_unregister_port(kmi->io); 171 clk_put(kmi->clk); 172 iounmap(kmi->base); 173 kfree(kmi); 174 amba_release_regions(dev); 175 return 0; 176 } 177 178 static int __maybe_unused amba_kmi_resume(struct device *dev) 179 { 180 struct amba_kmi_port *kmi = dev_get_drvdata(dev); 181 182 /* kick the serio layer to rescan this port */ 183 serio_reconnect(kmi->io); 184 185 return 0; 186 } 187 188 static SIMPLE_DEV_PM_OPS(amba_kmi_dev_pm_ops, NULL, amba_kmi_resume); 189 190 static const 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 .pm = &amba_kmi_dev_pm_ops, 205 }, 206 .id_table = amba_kmi_idtable, 207 .probe = amba_kmi_probe, 208 .remove = amba_kmi_remove, 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