1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Altera University Program PS2 controller driver 4 * 5 * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw> 6 * 7 * Based on sa1111ps2.c, which is: 8 * Copyright (C) 2002 Russell King 9 */ 10 11 #include <linux/module.h> 12 #include <linux/input.h> 13 #include <linux/serio.h> 14 #include <linux/interrupt.h> 15 #include <linux/platform_device.h> 16 #include <linux/io.h> 17 #include <linux/slab.h> 18 #include <linux/of.h> 19 20 #define DRV_NAME "altera_ps2" 21 22 struct ps2if { 23 struct serio *io; 24 void __iomem *base; 25 }; 26 27 /* 28 * Read all bytes waiting in the PS2 port. There should be 29 * at the most one, but we loop for safety. 30 */ 31 static irqreturn_t altera_ps2_rxint(int irq, void *dev_id) 32 { 33 struct ps2if *ps2if = dev_id; 34 unsigned int status; 35 irqreturn_t handled = IRQ_NONE; 36 37 while ((status = readl(ps2if->base)) & 0xffff0000) { 38 serio_interrupt(ps2if->io, status & 0xff, 0); 39 handled = IRQ_HANDLED; 40 } 41 42 return handled; 43 } 44 45 /* 46 * Write a byte to the PS2 port. 47 */ 48 static int altera_ps2_write(struct serio *io, unsigned char val) 49 { 50 struct ps2if *ps2if = io->port_data; 51 52 writel(val, ps2if->base); 53 return 0; 54 } 55 56 static int altera_ps2_open(struct serio *io) 57 { 58 struct ps2if *ps2if = io->port_data; 59 60 /* clear fifo */ 61 while (readl(ps2if->base) & 0xffff0000) 62 /* empty */; 63 64 writel(1, ps2if->base + 4); /* enable rx irq */ 65 return 0; 66 } 67 68 static void altera_ps2_close(struct serio *io) 69 { 70 struct ps2if *ps2if = io->port_data; 71 72 writel(0, ps2if->base + 4); /* disable rx irq */ 73 } 74 75 /* 76 * Add one device to this driver. 77 */ 78 static int altera_ps2_probe(struct platform_device *pdev) 79 { 80 struct ps2if *ps2if; 81 struct resource *res; 82 struct serio *serio; 83 int error, irq; 84 85 ps2if = devm_kzalloc(&pdev->dev, sizeof(struct ps2if), GFP_KERNEL); 86 if (!ps2if) 87 return -ENOMEM; 88 89 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 90 ps2if->base = devm_ioremap_resource(&pdev->dev, res); 91 if (IS_ERR(ps2if->base)) 92 return PTR_ERR(ps2if->base); 93 94 irq = platform_get_irq(pdev, 0); 95 if (irq < 0) 96 return -ENXIO; 97 98 error = devm_request_irq(&pdev->dev, irq, altera_ps2_rxint, 0, 99 pdev->name, ps2if); 100 if (error) { 101 dev_err(&pdev->dev, "could not request IRQ %d\n", irq); 102 return error; 103 } 104 105 serio = kzalloc(sizeof(struct serio), GFP_KERNEL); 106 if (!serio) 107 return -ENOMEM; 108 109 serio->id.type = SERIO_8042; 110 serio->write = altera_ps2_write; 111 serio->open = altera_ps2_open; 112 serio->close = altera_ps2_close; 113 strscpy(serio->name, dev_name(&pdev->dev), sizeof(serio->name)); 114 strscpy(serio->phys, dev_name(&pdev->dev), sizeof(serio->phys)); 115 serio->port_data = ps2if; 116 serio->dev.parent = &pdev->dev; 117 ps2if->io = serio; 118 119 dev_info(&pdev->dev, "base %p, irq %d\n", ps2if->base, irq); 120 121 serio_register_port(ps2if->io); 122 platform_set_drvdata(pdev, ps2if); 123 124 return 0; 125 } 126 127 /* 128 * Remove one device from this driver. 129 */ 130 static int altera_ps2_remove(struct platform_device *pdev) 131 { 132 struct ps2if *ps2if = platform_get_drvdata(pdev); 133 134 serio_unregister_port(ps2if->io); 135 136 return 0; 137 } 138 139 #ifdef CONFIG_OF 140 static const struct of_device_id altera_ps2_match[] = { 141 { .compatible = "ALTR,ps2-1.0", }, 142 { .compatible = "altr,ps2-1.0", }, 143 {}, 144 }; 145 MODULE_DEVICE_TABLE(of, altera_ps2_match); 146 #endif /* CONFIG_OF */ 147 148 /* 149 * Our device driver structure 150 */ 151 static struct platform_driver altera_ps2_driver = { 152 .probe = altera_ps2_probe, 153 .remove = altera_ps2_remove, 154 .driver = { 155 .name = DRV_NAME, 156 .of_match_table = of_match_ptr(altera_ps2_match), 157 }, 158 }; 159 module_platform_driver(altera_ps2_driver); 160 161 MODULE_DESCRIPTION("Altera University Program PS2 controller driver"); 162 MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>"); 163 MODULE_LICENSE("GPL"); 164 MODULE_ALIAS("platform:" DRV_NAME); 165