1 /* 2 * Altera University Program PS2 controller driver 3 * 4 * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw> 5 * 6 * Based on sa1111ps2.c, which is: 7 * Copyright (C) 2002 Russell King 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as 11 * published by the Free Software Foundation. 12 */ 13 14 #include <linux/module.h> 15 #include <linux/init.h> 16 #include <linux/input.h> 17 #include <linux/serio.h> 18 #include <linux/interrupt.h> 19 #include <linux/platform_device.h> 20 #include <linux/io.h> 21 22 #define DRV_NAME "altera_ps2" 23 24 struct ps2if { 25 struct serio *io; 26 struct resource *iomem_res; 27 void __iomem *base; 28 unsigned irq; 29 }; 30 31 /* 32 * Read all bytes waiting in the PS2 port. There should be 33 * at the most one, but we loop for safety. 34 */ 35 static irqreturn_t altera_ps2_rxint(int irq, void *dev_id) 36 { 37 struct ps2if *ps2if = dev_id; 38 unsigned int status; 39 int handled = IRQ_NONE; 40 41 while ((status = readl(ps2if->base)) & 0xffff0000) { 42 serio_interrupt(ps2if->io, status & 0xff, 0); 43 handled = IRQ_HANDLED; 44 } 45 46 return handled; 47 } 48 49 /* 50 * Write a byte to the PS2 port. 51 */ 52 static int altera_ps2_write(struct serio *io, unsigned char val) 53 { 54 struct ps2if *ps2if = io->port_data; 55 56 writel(val, ps2if->base); 57 return 0; 58 } 59 60 static int altera_ps2_open(struct serio *io) 61 { 62 struct ps2if *ps2if = io->port_data; 63 64 /* clear fifo */ 65 while (readl(ps2if->base) & 0xffff0000) 66 /* empty */; 67 68 writel(1, ps2if->base + 4); /* enable rx irq */ 69 return 0; 70 } 71 72 static void altera_ps2_close(struct serio *io) 73 { 74 struct ps2if *ps2if = io->port_data; 75 76 writel(0, ps2if->base); /* disable rx irq */ 77 } 78 79 /* 80 * Add one device to this driver. 81 */ 82 static int altera_ps2_probe(struct platform_device *pdev) 83 { 84 struct ps2if *ps2if; 85 struct serio *serio; 86 int error; 87 88 ps2if = kzalloc(sizeof(struct ps2if), GFP_KERNEL); 89 serio = kzalloc(sizeof(struct serio), GFP_KERNEL); 90 if (!ps2if || !serio) { 91 error = -ENOMEM; 92 goto err_free_mem; 93 } 94 95 serio->id.type = SERIO_8042; 96 serio->write = altera_ps2_write; 97 serio->open = altera_ps2_open; 98 serio->close = altera_ps2_close; 99 strlcpy(serio->name, dev_name(&pdev->dev), sizeof(serio->name)); 100 strlcpy(serio->phys, dev_name(&pdev->dev), sizeof(serio->phys)); 101 serio->port_data = ps2if; 102 serio->dev.parent = &pdev->dev; 103 ps2if->io = serio; 104 105 ps2if->iomem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 106 if (ps2if->iomem_res == NULL) { 107 error = -ENOENT; 108 goto err_free_mem; 109 } 110 111 ps2if->irq = platform_get_irq(pdev, 0); 112 if (ps2if->irq < 0) { 113 error = -ENXIO; 114 goto err_free_mem; 115 } 116 117 if (!request_mem_region(ps2if->iomem_res->start, 118 resource_size(ps2if->iomem_res), pdev->name)) { 119 error = -EBUSY; 120 goto err_free_mem; 121 } 122 123 ps2if->base = ioremap(ps2if->iomem_res->start, 124 resource_size(ps2if->iomem_res)); 125 if (!ps2if->base) { 126 error = -ENOMEM; 127 goto err_free_res; 128 } 129 130 error = request_irq(ps2if->irq, altera_ps2_rxint, 0, pdev->name, ps2if); 131 if (error) { 132 dev_err(&pdev->dev, "could not allocate IRQ %d: %d\n", 133 ps2if->irq, error); 134 goto err_unmap; 135 } 136 137 dev_info(&pdev->dev, "base %p, irq %d\n", ps2if->base, ps2if->irq); 138 139 serio_register_port(ps2if->io); 140 platform_set_drvdata(pdev, ps2if); 141 142 return 0; 143 144 err_unmap: 145 iounmap(ps2if->base); 146 err_free_res: 147 release_mem_region(ps2if->iomem_res->start, 148 resource_size(ps2if->iomem_res)); 149 err_free_mem: 150 kfree(ps2if); 151 kfree(serio); 152 return error; 153 } 154 155 /* 156 * Remove one device from this driver. 157 */ 158 static int altera_ps2_remove(struct platform_device *pdev) 159 { 160 struct ps2if *ps2if = platform_get_drvdata(pdev); 161 162 platform_set_drvdata(pdev, NULL); 163 serio_unregister_port(ps2if->io); 164 free_irq(ps2if->irq, ps2if); 165 iounmap(ps2if->base); 166 release_mem_region(ps2if->iomem_res->start, 167 resource_size(ps2if->iomem_res)); 168 kfree(ps2if); 169 170 return 0; 171 } 172 173 /* 174 * Our device driver structure 175 */ 176 static struct platform_driver altera_ps2_driver = { 177 .probe = altera_ps2_probe, 178 .remove = altera_ps2_remove, 179 .driver = { 180 .name = DRV_NAME, 181 }, 182 }; 183 184 static int __init altera_ps2_init(void) 185 { 186 return platform_driver_register(&altera_ps2_driver); 187 } 188 189 static void __exit altera_ps2_exit(void) 190 { 191 platform_driver_unregister(&altera_ps2_driver); 192 } 193 194 module_init(altera_ps2_init); 195 module_exit(altera_ps2_exit); 196 197 MODULE_DESCRIPTION("Altera University Program PS2 controller driver"); 198 MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>"); 199 MODULE_LICENSE("GPL"); 200 MODULE_ALIAS("platform:" DRV_NAME); 201