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/input.h> 16 #include <linux/serio.h> 17 #include <linux/interrupt.h> 18 #include <linux/platform_device.h> 19 #include <linux/io.h> 20 #include <linux/slab.h> 21 #include <linux/of.h> 22 23 #define DRV_NAME "altera_ps2" 24 25 struct ps2if { 26 struct serio *io; 27 void __iomem *base; 28 }; 29 30 /* 31 * Read all bytes waiting in the PS2 port. There should be 32 * at the most one, but we loop for safety. 33 */ 34 static irqreturn_t altera_ps2_rxint(int irq, void *dev_id) 35 { 36 struct ps2if *ps2if = dev_id; 37 unsigned int status; 38 irqreturn_t handled = IRQ_NONE; 39 40 while ((status = readl(ps2if->base)) & 0xffff0000) { 41 serio_interrupt(ps2if->io, status & 0xff, 0); 42 handled = IRQ_HANDLED; 43 } 44 45 return handled; 46 } 47 48 /* 49 * Write a byte to the PS2 port. 50 */ 51 static int altera_ps2_write(struct serio *io, unsigned char val) 52 { 53 struct ps2if *ps2if = io->port_data; 54 55 writel(val, ps2if->base); 56 return 0; 57 } 58 59 static int altera_ps2_open(struct serio *io) 60 { 61 struct ps2if *ps2if = io->port_data; 62 63 /* clear fifo */ 64 while (readl(ps2if->base) & 0xffff0000) 65 /* empty */; 66 67 writel(1, ps2if->base + 4); /* enable rx irq */ 68 return 0; 69 } 70 71 static void altera_ps2_close(struct serio *io) 72 { 73 struct ps2if *ps2if = io->port_data; 74 75 writel(0, ps2if->base + 4); /* disable rx irq */ 76 } 77 78 /* 79 * Add one device to this driver. 80 */ 81 static int altera_ps2_probe(struct platform_device *pdev) 82 { 83 struct ps2if *ps2if; 84 struct resource *res; 85 struct serio *serio; 86 int error, irq; 87 88 ps2if = devm_kzalloc(&pdev->dev, sizeof(struct ps2if), GFP_KERNEL); 89 if (!ps2if) 90 return -ENOMEM; 91 92 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 93 ps2if->base = devm_ioremap_resource(&pdev->dev, res); 94 if (IS_ERR(ps2if->base)) 95 return PTR_ERR(ps2if->base); 96 97 irq = platform_get_irq(pdev, 0); 98 if (irq < 0) 99 return -ENXIO; 100 101 error = devm_request_irq(&pdev->dev, irq, altera_ps2_rxint, 0, 102 pdev->name, ps2if); 103 if (error) { 104 dev_err(&pdev->dev, "could not request IRQ %d\n", irq); 105 return error; 106 } 107 108 serio = kzalloc(sizeof(struct serio), GFP_KERNEL); 109 if (!serio) 110 return -ENOMEM; 111 112 serio->id.type = SERIO_8042; 113 serio->write = altera_ps2_write; 114 serio->open = altera_ps2_open; 115 serio->close = altera_ps2_close; 116 strlcpy(serio->name, dev_name(&pdev->dev), sizeof(serio->name)); 117 strlcpy(serio->phys, dev_name(&pdev->dev), sizeof(serio->phys)); 118 serio->port_data = ps2if; 119 serio->dev.parent = &pdev->dev; 120 ps2if->io = serio; 121 122 dev_info(&pdev->dev, "base %p, irq %d\n", ps2if->base, irq); 123 124 serio_register_port(ps2if->io); 125 platform_set_drvdata(pdev, ps2if); 126 127 return 0; 128 } 129 130 /* 131 * Remove one device from this driver. 132 */ 133 static int altera_ps2_remove(struct platform_device *pdev) 134 { 135 struct ps2if *ps2if = platform_get_drvdata(pdev); 136 137 serio_unregister_port(ps2if->io); 138 139 return 0; 140 } 141 142 #ifdef CONFIG_OF 143 static const struct of_device_id altera_ps2_match[] = { 144 { .compatible = "ALTR,ps2-1.0", }, 145 { .compatible = "altr,ps2-1.0", }, 146 {}, 147 }; 148 MODULE_DEVICE_TABLE(of, altera_ps2_match); 149 #endif /* CONFIG_OF */ 150 151 /* 152 * Our device driver structure 153 */ 154 static struct platform_driver altera_ps2_driver = { 155 .probe = altera_ps2_probe, 156 .remove = altera_ps2_remove, 157 .driver = { 158 .name = DRV_NAME, 159 .of_match_table = of_match_ptr(altera_ps2_match), 160 }, 161 }; 162 module_platform_driver(altera_ps2_driver); 163 164 MODULE_DESCRIPTION("Altera University Program PS2 controller driver"); 165 MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>"); 166 MODULE_LICENSE("GPL"); 167 MODULE_ALIAS("platform:" DRV_NAME); 168