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 struct resource *iomem_res; 28 void __iomem *base; 29 unsigned irq; 30 }; 31 32 /* 33 * Read all bytes waiting in the PS2 port. There should be 34 * at the most one, but we loop for safety. 35 */ 36 static irqreturn_t altera_ps2_rxint(int irq, void *dev_id) 37 { 38 struct ps2if *ps2if = dev_id; 39 unsigned int status; 40 int handled = IRQ_NONE; 41 42 while ((status = readl(ps2if->base)) & 0xffff0000) { 43 serio_interrupt(ps2if->io, status & 0xff, 0); 44 handled = IRQ_HANDLED; 45 } 46 47 return handled; 48 } 49 50 /* 51 * Write a byte to the PS2 port. 52 */ 53 static int altera_ps2_write(struct serio *io, unsigned char val) 54 { 55 struct ps2if *ps2if = io->port_data; 56 57 writel(val, ps2if->base); 58 return 0; 59 } 60 61 static int altera_ps2_open(struct serio *io) 62 { 63 struct ps2if *ps2if = io->port_data; 64 65 /* clear fifo */ 66 while (readl(ps2if->base) & 0xffff0000) 67 /* empty */; 68 69 writel(1, ps2if->base + 4); /* enable rx irq */ 70 return 0; 71 } 72 73 static void altera_ps2_close(struct serio *io) 74 { 75 struct ps2if *ps2if = io->port_data; 76 77 writel(0, ps2if->base); /* disable rx irq */ 78 } 79 80 /* 81 * Add one device to this driver. 82 */ 83 static int altera_ps2_probe(struct platform_device *pdev) 84 { 85 struct ps2if *ps2if; 86 struct serio *serio; 87 int error, irq; 88 89 ps2if = kzalloc(sizeof(struct ps2if), GFP_KERNEL); 90 serio = kzalloc(sizeof(struct serio), GFP_KERNEL); 91 if (!ps2if || !serio) { 92 error = -ENOMEM; 93 goto err_free_mem; 94 } 95 96 serio->id.type = SERIO_8042; 97 serio->write = altera_ps2_write; 98 serio->open = altera_ps2_open; 99 serio->close = altera_ps2_close; 100 strlcpy(serio->name, dev_name(&pdev->dev), sizeof(serio->name)); 101 strlcpy(serio->phys, dev_name(&pdev->dev), sizeof(serio->phys)); 102 serio->port_data = ps2if; 103 serio->dev.parent = &pdev->dev; 104 ps2if->io = serio; 105 106 ps2if->iomem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 107 if (ps2if->iomem_res == NULL) { 108 error = -ENOENT; 109 goto err_free_mem; 110 } 111 112 113 irq = platform_get_irq(pdev, 0); 114 if (irq < 0) { 115 error = -ENXIO; 116 goto err_free_mem; 117 } 118 ps2if->irq = irq; 119 120 if (!request_mem_region(ps2if->iomem_res->start, 121 resource_size(ps2if->iomem_res), pdev->name)) { 122 error = -EBUSY; 123 goto err_free_mem; 124 } 125 126 ps2if->base = ioremap(ps2if->iomem_res->start, 127 resource_size(ps2if->iomem_res)); 128 if (!ps2if->base) { 129 error = -ENOMEM; 130 goto err_free_res; 131 } 132 133 error = request_irq(ps2if->irq, altera_ps2_rxint, 0, pdev->name, ps2if); 134 if (error) { 135 dev_err(&pdev->dev, "could not allocate IRQ %d: %d\n", 136 ps2if->irq, error); 137 goto err_unmap; 138 } 139 140 dev_info(&pdev->dev, "base %p, irq %d\n", ps2if->base, ps2if->irq); 141 142 serio_register_port(ps2if->io); 143 platform_set_drvdata(pdev, ps2if); 144 145 return 0; 146 147 err_unmap: 148 iounmap(ps2if->base); 149 err_free_res: 150 release_mem_region(ps2if->iomem_res->start, 151 resource_size(ps2if->iomem_res)); 152 err_free_mem: 153 kfree(ps2if); 154 kfree(serio); 155 return error; 156 } 157 158 /* 159 * Remove one device from this driver. 160 */ 161 static int altera_ps2_remove(struct platform_device *pdev) 162 { 163 struct ps2if *ps2if = platform_get_drvdata(pdev); 164 165 serio_unregister_port(ps2if->io); 166 free_irq(ps2if->irq, ps2if); 167 iounmap(ps2if->base); 168 release_mem_region(ps2if->iomem_res->start, 169 resource_size(ps2if->iomem_res)); 170 kfree(ps2if); 171 172 return 0; 173 } 174 175 #ifdef CONFIG_OF 176 static const struct of_device_id altera_ps2_match[] = { 177 { .compatible = "ALTR,ps2-1.0", }, 178 { .compatible = "altr,ps2-1.0", }, 179 {}, 180 }; 181 MODULE_DEVICE_TABLE(of, altera_ps2_match); 182 #endif /* CONFIG_OF */ 183 184 /* 185 * Our device driver structure 186 */ 187 static struct platform_driver altera_ps2_driver = { 188 .probe = altera_ps2_probe, 189 .remove = altera_ps2_remove, 190 .driver = { 191 .name = DRV_NAME, 192 .owner = THIS_MODULE, 193 .of_match_table = of_match_ptr(altera_ps2_match), 194 }, 195 }; 196 module_platform_driver(altera_ps2_driver); 197 198 MODULE_DESCRIPTION("Altera University Program PS2 controller driver"); 199 MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>"); 200 MODULE_LICENSE("GPL"); 201 MODULE_ALIAS("platform:" DRV_NAME); 202