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 #include <linux/slab.h> 22 #include <linux/of.h> 23 24 #define DRV_NAME "altera_ps2" 25 26 struct ps2if { 27 struct serio *io; 28 struct resource *iomem_res; 29 void __iomem *base; 30 unsigned irq; 31 }; 32 33 /* 34 * Read all bytes waiting in the PS2 port. There should be 35 * at the most one, but we loop for safety. 36 */ 37 static irqreturn_t altera_ps2_rxint(int irq, void *dev_id) 38 { 39 struct ps2if *ps2if = dev_id; 40 unsigned int status; 41 int handled = IRQ_NONE; 42 43 while ((status = readl(ps2if->base)) & 0xffff0000) { 44 serio_interrupt(ps2if->io, status & 0xff, 0); 45 handled = IRQ_HANDLED; 46 } 47 48 return handled; 49 } 50 51 /* 52 * Write a byte to the PS2 port. 53 */ 54 static int altera_ps2_write(struct serio *io, unsigned char val) 55 { 56 struct ps2if *ps2if = io->port_data; 57 58 writel(val, ps2if->base); 59 return 0; 60 } 61 62 static int altera_ps2_open(struct serio *io) 63 { 64 struct ps2if *ps2if = io->port_data; 65 66 /* clear fifo */ 67 while (readl(ps2if->base) & 0xffff0000) 68 /* empty */; 69 70 writel(1, ps2if->base + 4); /* enable rx irq */ 71 return 0; 72 } 73 74 static void altera_ps2_close(struct serio *io) 75 { 76 struct ps2if *ps2if = io->port_data; 77 78 writel(0, ps2if->base); /* disable rx irq */ 79 } 80 81 /* 82 * Add one device to this driver. 83 */ 84 static int altera_ps2_probe(struct platform_device *pdev) 85 { 86 struct ps2if *ps2if; 87 struct serio *serio; 88 int error, irq; 89 90 ps2if = kzalloc(sizeof(struct ps2if), GFP_KERNEL); 91 serio = kzalloc(sizeof(struct serio), GFP_KERNEL); 92 if (!ps2if || !serio) { 93 error = -ENOMEM; 94 goto err_free_mem; 95 } 96 97 serio->id.type = SERIO_8042; 98 serio->write = altera_ps2_write; 99 serio->open = altera_ps2_open; 100 serio->close = altera_ps2_close; 101 strlcpy(serio->name, dev_name(&pdev->dev), sizeof(serio->name)); 102 strlcpy(serio->phys, dev_name(&pdev->dev), sizeof(serio->phys)); 103 serio->port_data = ps2if; 104 serio->dev.parent = &pdev->dev; 105 ps2if->io = serio; 106 107 ps2if->iomem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 108 if (ps2if->iomem_res == NULL) { 109 error = -ENOENT; 110 goto err_free_mem; 111 } 112 113 114 irq = platform_get_irq(pdev, 0); 115 if (irq < 0) { 116 error = -ENXIO; 117 goto err_free_mem; 118 } 119 ps2if->irq = irq; 120 121 if (!request_mem_region(ps2if->iomem_res->start, 122 resource_size(ps2if->iomem_res), pdev->name)) { 123 error = -EBUSY; 124 goto err_free_mem; 125 } 126 127 ps2if->base = ioremap(ps2if->iomem_res->start, 128 resource_size(ps2if->iomem_res)); 129 if (!ps2if->base) { 130 error = -ENOMEM; 131 goto err_free_res; 132 } 133 134 error = request_irq(ps2if->irq, altera_ps2_rxint, 0, pdev->name, ps2if); 135 if (error) { 136 dev_err(&pdev->dev, "could not allocate IRQ %d: %d\n", 137 ps2if->irq, error); 138 goto err_unmap; 139 } 140 141 dev_info(&pdev->dev, "base %p, irq %d\n", ps2if->base, ps2if->irq); 142 143 serio_register_port(ps2if->io); 144 platform_set_drvdata(pdev, ps2if); 145 146 return 0; 147 148 err_unmap: 149 iounmap(ps2if->base); 150 err_free_res: 151 release_mem_region(ps2if->iomem_res->start, 152 resource_size(ps2if->iomem_res)); 153 err_free_mem: 154 kfree(ps2if); 155 kfree(serio); 156 return error; 157 } 158 159 /* 160 * Remove one device from this driver. 161 */ 162 static int altera_ps2_remove(struct platform_device *pdev) 163 { 164 struct ps2if *ps2if = platform_get_drvdata(pdev); 165 166 platform_set_drvdata(pdev, NULL); 167 serio_unregister_port(ps2if->io); 168 free_irq(ps2if->irq, ps2if); 169 iounmap(ps2if->base); 170 release_mem_region(ps2if->iomem_res->start, 171 resource_size(ps2if->iomem_res)); 172 kfree(ps2if); 173 174 return 0; 175 } 176 177 #ifdef CONFIG_OF 178 static const struct of_device_id altera_ps2_match[] = { 179 { .compatible = "ALTR,ps2-1.0", }, 180 {}, 181 }; 182 MODULE_DEVICE_TABLE(of, altera_ps2_match); 183 #endif /* CONFIG_OF */ 184 185 /* 186 * Our device driver structure 187 */ 188 static struct platform_driver altera_ps2_driver = { 189 .probe = altera_ps2_probe, 190 .remove = altera_ps2_remove, 191 .driver = { 192 .name = DRV_NAME, 193 .owner = THIS_MODULE, 194 .of_match_table = of_match_ptr(altera_ps2_match), 195 }, 196 }; 197 module_platform_driver(altera_ps2_driver); 198 199 MODULE_DESCRIPTION("Altera University Program PS2 controller driver"); 200 MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>"); 201 MODULE_LICENSE("GPL"); 202 MODULE_ALIAS("platform:" DRV_NAME); 203