input/serio/ambakmi.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  *  linux/drivers/input/serio/ambakmi.c
0004  *
0005  *  Copyright (C) 2000-2003 Deep Blue Solutions Ltd.
0006  *  Copyright (C) 2002 Russell King.
0007  */
0008 #include <linux/module.h>
0009 #include <linux/serio.h>
0010 #include <linux/errno.h>
0011 #include <linux/interrupt.h>
0012 #include <linux/ioport.h>
0013 #include <linux/device.h>
0014 #include <linux/delay.h>
0015 #include <linux/slab.h>
0016 #include <linux/err.h>
0017 #include <linux/amba/bus.h>
0018 #include <linux/amba/kmi.h>
0019 #include <linux/clk.h>
0020
0021 #include <asm/io.h>
0022 #include <asm/irq.h>
0023
0024 #define KMI_BASE    (kmi->base)
0025
0026 struct amba_kmi_port {
0027     struct serio        *io;
0028     struct clk      *clk;
0029     void __iomem        *base;
0030     unsigned int        irq;
0031     unsigned int        divisor;
0032     unsigned int        open;
0033 };
0034
0035 static irqreturn_t amba_kmi_int(int irq, void *dev_id)
0036 {
0037     struct amba_kmi_port *kmi = dev_id;
0038     unsigned int status = readb(KMIIR);
0039     int handled = IRQ_NONE;
0040
0041     while (status & KMIIR_RXINTR) {
0042         serio_interrupt(kmi->io, readb(KMIDATA), 0);
0043         status = readb(KMIIR);
0044         handled = IRQ_HANDLED;
0045     }
0046
0047     return handled;
0048 }
0049
0050 static int amba_kmi_write(struct serio *io, unsigned char val)
0051 {
0052     struct amba_kmi_port *kmi = io->port_data;
0053     unsigned int timeleft = 10000; /* timeout in 100ms */
0054
0055     while ((readb(KMISTAT) & KMISTAT_TXEMPTY) == 0 && --timeleft)
0056         udelay(10);
0057
0058     if (timeleft)
0059         writeb(val, KMIDATA);
0060
0061     return timeleft ? 0 : SERIO_TIMEOUT;
0062 }
0063
0064 static int amba_kmi_open(struct serio *io)
0065 {
0066     struct amba_kmi_port *kmi = io->port_data;
0067     unsigned int divisor;
0068     int ret;
0069
0070     ret = clk_prepare_enable(kmi->clk);
0071     if (ret)
0072         goto out;
0073
0074     divisor = clk_get_rate(kmi->clk) / 8000000 - 1;
0075     writeb(divisor, KMICLKDIV);
0076     writeb(KMICR_EN, KMICR);
0077
0078     ret = request_irq(kmi->irq, amba_kmi_int, IRQF_SHARED, "kmi-pl050",
0079               kmi);
0080     if (ret) {
0081         printk(KERN_ERR "kmi: failed to claim IRQ%d\n", kmi->irq);
0082         writeb(0, KMICR);
0083         goto clk_disable;
0084     }
0085
0086     writeb(KMICR_EN | KMICR_RXINTREN, KMICR);
0087
0088     return 0;
0089
0090  clk_disable:
0091     clk_disable_unprepare(kmi->clk);
0092  out:
0093     return ret;
0094 }
0095
0096 static void amba_kmi_close(struct serio *io)
0097 {
0098     struct amba_kmi_port *kmi = io->port_data;
0099
0100     writeb(0, KMICR);
0101
0102     free_irq(kmi->irq, kmi);
0103     clk_disable_unprepare(kmi->clk);
0104 }
0105
0106 static int amba_kmi_probe(struct amba_device *dev,
0107     const struct amba_id *id)
0108 {
0109     struct amba_kmi_port *kmi;
0110     struct serio *io;
0111     int ret;
0112
0113     ret = amba_request_regions(dev, NULL);
0114     if (ret)
0115         return ret;
0116
0117     kmi = kzalloc(sizeof(struct amba_kmi_port), GFP_KERNEL);
0118     io = kzalloc(sizeof(struct serio), GFP_KERNEL);
0119     if (!kmi || !io) {
0120         ret = -ENOMEM;
0121         goto out;
0122     }
0123
0124
0125     io->id.type = SERIO_8042;
0126     io->write   = amba_kmi_write;
0127     io->open    = amba_kmi_open;
0128     io->close   = amba_kmi_close;
0129     strlcpy(io->name, dev_name(&dev->dev), sizeof(io->name));
0130     strlcpy(io->phys, dev_name(&dev->dev), sizeof(io->phys));
0131     io->port_data   = kmi;
0132     io->dev.parent  = &dev->dev;
0133
0134     kmi->io     = io;
0135     kmi->base   = ioremap(dev->res.start, resource_size(&dev->res));
0136     if (!kmi->base) {
0137         ret = -ENOMEM;
0138         goto out;
0139     }
0140
0141     kmi->clk = clk_get(&dev->dev, "KMIREFCLK");
0142     if (IS_ERR(kmi->clk)) {
0143         ret = PTR_ERR(kmi->clk);
0144         goto unmap;
0145     }
0146
0147     kmi->irq = dev->irq[0];
0148     amba_set_drvdata(dev, kmi);
0149
0150     serio_register_port(kmi->io);
0151     return 0;
0152
0153  unmap:
0154     iounmap(kmi->base);
0155  out:
0156     kfree(kmi);
0157     kfree(io);
0158     amba_release_regions(dev);
0159     return ret;
0160 }
0161
0162 static void amba_kmi_remove(struct amba_device *dev)
0163 {
0164     struct amba_kmi_port *kmi = amba_get_drvdata(dev);
0165
0166     serio_unregister_port(kmi->io);
0167     clk_put(kmi->clk);
0168     iounmap(kmi->base);
0169     kfree(kmi);
0170     amba_release_regions(dev);
0171 }
0172
0173 static int __maybe_unused amba_kmi_resume(struct device *dev)
0174 {
0175     struct amba_kmi_port *kmi = dev_get_drvdata(dev);
0176
0177     /* kick the serio layer to rescan this port */
0178     serio_reconnect(kmi->io);
0179
0180     return 0;
0181 }
0182
0183 static SIMPLE_DEV_PM_OPS(amba_kmi_dev_pm_ops, NULL, amba_kmi_resume);
0184
0185 static const struct amba_id amba_kmi_idtable[] = {
0186     {
0187         .id = 0x00041050,
0188         .mask   = 0x000fffff,
0189     },
0190     { 0, 0 }
0191 };
0192
0193 MODULE_DEVICE_TABLE(amba, amba_kmi_idtable);
0194
0195 static struct amba_driver ambakmi_driver = {
0196     .drv        = {
0197         .name   = "kmi-pl050",
0198         .owner  = THIS_MODULE,
0199         .pm = &amba_kmi_dev_pm_ops,
0200     },
0201     .id_table   = amba_kmi_idtable,
0202     .probe      = amba_kmi_probe,
0203     .remove     = amba_kmi_remove,
0204 };
0205
0206 module_amba_driver(ambakmi_driver);
0207
0208 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
0209 MODULE_DESCRIPTION("AMBA KMI controller driver");
0210 MODULE_LICENSE("GPL");