1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * linux/drivers/input/serio/ambakmi.c 4 * 5 * Copyright (C) 2000-2003 Deep Blue Solutions Ltd. 6 * Copyright (C) 2002 Russell King. 7 */ 8 #include <linux/module.h> 9 #include <linux/serio.h> 10 #include <linux/errno.h> 11 #include <linux/interrupt.h> 12 #include <linux/ioport.h> 13 #include <linux/device.h> 14 #include <linux/delay.h> 15 #include <linux/slab.h> 16 #include <linux/err.h> 17 #include <linux/amba/bus.h> 18 #include <linux/amba/kmi.h> 19 #include <linux/clk.h> 20 21 #include <asm/io.h> 22 #include <asm/irq.h> 23 24 #define KMI_BASE (kmi->base) 25 26 struct amba_kmi_port { 27 struct serio *io; 28 struct clk *clk; 29 void __iomem *base; 30 unsigned int irq; 31 unsigned int divisor; 32 unsigned int open; 33 }; 34 35 static irqreturn_t amba_kmi_int(int irq, void *dev_id) 36 { 37 struct amba_kmi_port *kmi = dev_id; 38 unsigned int status = readb(KMIIR); 39 int handled = IRQ_NONE; 40 41 while (status & KMIIR_RXINTR) { 42 serio_interrupt(kmi->io, readb(KMIDATA), 0); 43 status = readb(KMIIR); 44 handled = IRQ_HANDLED; 45 } 46 47 return handled; 48 } 49 50 static int amba_kmi_write(struct serio *io, unsigned char val) 51 { 52 struct amba_kmi_port *kmi = io->port_data; 53 unsigned int timeleft = 10000; /* timeout in 100ms */ 54 55 while ((readb(KMISTAT) & KMISTAT_TXEMPTY) == 0 && --timeleft) 56 udelay(10); 57 58 if (timeleft) 59 writeb(val, KMIDATA); 60 61 return timeleft ? 0 : SERIO_TIMEOUT; 62 } 63 64 static int amba_kmi_open(struct serio *io) 65 { 66 struct amba_kmi_port *kmi = io->port_data; 67 unsigned int divisor; 68 int ret; 69 70 ret = clk_prepare_enable(kmi->clk); 71 if (ret) 72 goto out; 73 74 divisor = clk_get_rate(kmi->clk) / 8000000 - 1; 75 writeb(divisor, KMICLKDIV); 76 writeb(KMICR_EN, KMICR); 77 78 ret = request_irq(kmi->irq, amba_kmi_int, IRQF_SHARED, "kmi-pl050", 79 kmi); 80 if (ret) { 81 printk(KERN_ERR "kmi: failed to claim IRQ%d\n", kmi->irq); 82 writeb(0, KMICR); 83 goto clk_disable; 84 } 85 86 writeb(KMICR_EN | KMICR_RXINTREN, KMICR); 87 88 return 0; 89 90 clk_disable: 91 clk_disable_unprepare(kmi->clk); 92 out: 93 return ret; 94 } 95 96 static void amba_kmi_close(struct serio *io) 97 { 98 struct amba_kmi_port *kmi = io->port_data; 99 100 writeb(0, KMICR); 101 102 free_irq(kmi->irq, kmi); 103 clk_disable_unprepare(kmi->clk); 104 } 105 106 static int amba_kmi_probe(struct amba_device *dev, 107 const struct amba_id *id) 108 { 109 struct amba_kmi_port *kmi; 110 struct serio *io; 111 int ret; 112 113 ret = amba_request_regions(dev, NULL); 114 if (ret) 115 return ret; 116 117 kmi = kzalloc(sizeof(struct amba_kmi_port), GFP_KERNEL); 118 io = kzalloc(sizeof(struct serio), GFP_KERNEL); 119 if (!kmi || !io) { 120 ret = -ENOMEM; 121 goto out; 122 } 123 124 125 io->id.type = SERIO_8042; 126 io->write = amba_kmi_write; 127 io->open = amba_kmi_open; 128 io->close = amba_kmi_close; 129 strscpy(io->name, dev_name(&dev->dev), sizeof(io->name)); 130 strscpy(io->phys, dev_name(&dev->dev), sizeof(io->phys)); 131 io->port_data = kmi; 132 io->dev.parent = &dev->dev; 133 134 kmi->io = io; 135 kmi->base = ioremap(dev->res.start, resource_size(&dev->res)); 136 if (!kmi->base) { 137 ret = -ENOMEM; 138 goto out; 139 } 140 141 kmi->clk = clk_get(&dev->dev, "KMIREFCLK"); 142 if (IS_ERR(kmi->clk)) { 143 ret = PTR_ERR(kmi->clk); 144 goto unmap; 145 } 146 147 kmi->irq = dev->irq[0]; 148 amba_set_drvdata(dev, kmi); 149 150 serio_register_port(kmi->io); 151 return 0; 152 153 unmap: 154 iounmap(kmi->base); 155 out: 156 kfree(kmi); 157 kfree(io); 158 amba_release_regions(dev); 159 return ret; 160 } 161 162 static void amba_kmi_remove(struct amba_device *dev) 163 { 164 struct amba_kmi_port *kmi = amba_get_drvdata(dev); 165 166 serio_unregister_port(kmi->io); 167 clk_put(kmi->clk); 168 iounmap(kmi->base); 169 kfree(kmi); 170 amba_release_regions(dev); 171 } 172 173 static int __maybe_unused amba_kmi_resume(struct device *dev) 174 { 175 struct amba_kmi_port *kmi = dev_get_drvdata(dev); 176 177 /* kick the serio layer to rescan this port */ 178 serio_reconnect(kmi->io); 179 180 return 0; 181 } 182 183 static SIMPLE_DEV_PM_OPS(amba_kmi_dev_pm_ops, NULL, amba_kmi_resume); 184 185 static const struct amba_id amba_kmi_idtable[] = { 186 { 187 .id = 0x00041050, 188 .mask = 0x000fffff, 189 }, 190 { 0, 0 } 191 }; 192 193 MODULE_DEVICE_TABLE(amba, amba_kmi_idtable); 194 195 static struct amba_driver ambakmi_driver = { 196 .drv = { 197 .name = "kmi-pl050", 198 .owner = THIS_MODULE, 199 .pm = &amba_kmi_dev_pm_ops, 200 }, 201 .id_table = amba_kmi_idtable, 202 .probe = amba_kmi_probe, 203 .remove = amba_kmi_remove, 204 }; 205 206 module_amba_driver(ambakmi_driver); 207 208 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); 209 MODULE_DESCRIPTION("AMBA KMI controller driver"); 210 MODULE_LICENSE("GPL"); 211