| /* display7seg.c - Driver implementation for the 7-segment display |
| * present on Sun Microsystems CP1400 and CP1500 |
| * |
| * Copyright (c) 2000 Eric Brower (ebrower@usa.net) |
| */ |
| |
| #include <linux/device.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/fs.h> |
| #include <linux/errno.h> |
| #include <linux/major.h> |
| #include <linux/miscdevice.h> |
| #include <linux/ioport.h> /* request_region */ |
| #include <linux/slab.h> |
| #include <linux/mutex.h> |
| #include <linux/of.h> |
| #include <linux/of_device.h> |
| #include <linux/atomic.h> |
| #include <asm/uaccess.h> /* put_/get_user */ |
| #include <asm/io.h> |
| |
| #include <asm/display7seg.h> |
| |
| #define D7S_MINOR 193 |
| #define DRIVER_NAME "d7s" |
| #define PFX DRIVER_NAME ": " |
| |
| static DEFINE_MUTEX(d7s_mutex); |
| static int sol_compat = 0; /* Solaris compatibility mode */ |
| |
| /* Solaris compatibility flag - |
| * The Solaris implementation omits support for several |
| * documented driver features (ref Sun doc 806-0180-03). |
| * By default, this module supports the documented driver |
| * abilities, rather than the Solaris implementation: |
| * |
| * 1) Device ALWAYS reverts to OBP-specified FLIPPED mode |
| * upon closure of device or module unload. |
| * 2) Device ioctls D7SIOCRD/D7SIOCWR honor toggling of |
| * FLIP bit |
| * |
| * If you wish the device to operate as under Solaris, |
| * omitting above features, set this parameter to non-zero. |
| */ |
| module_param(sol_compat, int, 0); |
| MODULE_PARM_DESC(sol_compat, |
| "Disables documented functionality omitted from Solaris driver"); |
| |
| MODULE_AUTHOR("Eric Brower <ebrower@usa.net>"); |
| MODULE_DESCRIPTION("7-Segment Display driver for Sun Microsystems CP1400/1500"); |
| MODULE_LICENSE("GPL"); |
| MODULE_SUPPORTED_DEVICE("d7s"); |
| |
| struct d7s { |
| void __iomem *regs; |
| bool flipped; |
| }; |
| struct d7s *d7s_device; |
| |
| /* |
| * Register block address- see header for details |
| * ----------------------------------------- |
| * | DP | ALARM | FLIP | 4 | 3 | 2 | 1 | 0 | |
| * ----------------------------------------- |
| * |
| * DP - Toggles decimal point on/off |
| * ALARM - Toggles "Alarm" LED green/red |
| * FLIP - Inverts display for upside-down mounted board |
| * bits 0-4 - 7-segment display contents |
| */ |
| static atomic_t d7s_users = ATOMIC_INIT(0); |
| |
| static int d7s_open(struct inode *inode, struct file *f) |
| { |
| if (D7S_MINOR != iminor(inode)) |
| return -ENODEV; |
| atomic_inc(&d7s_users); |
| return 0; |
| } |
| |
| static int d7s_release(struct inode *inode, struct file *f) |
| { |
| /* Reset flipped state to OBP default only if |
| * no other users have the device open and we |
| * are not operating in solaris-compat mode |
| */ |
| if (atomic_dec_and_test(&d7s_users) && !sol_compat) { |
| struct d7s *p = d7s_device; |
| u8 regval = 0; |
| |
| regval = readb(p->regs); |
| if (p->flipped) |
| regval |= D7S_FLIP; |
| else |
| regval &= ~D7S_FLIP; |
| writeb(regval, p->regs); |
| } |
| |
| return 0; |
| } |
| |
| static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
| { |
| struct d7s *p = d7s_device; |
| u8 regs = readb(p->regs); |
| int error = 0; |
| u8 ireg = 0; |
| |
| if (D7S_MINOR != iminor(file_inode(file))) |
| return -ENODEV; |
| |
| mutex_lock(&d7s_mutex); |
| switch (cmd) { |
| case D7SIOCWR: |
| /* assign device register values we mask-out D7S_FLIP |
| * if in sol_compat mode |
| */ |
| if (get_user(ireg, (int __user *) arg)) { |
| error = -EFAULT; |
| break; |
| } |
| if (sol_compat) { |
| if (regs & D7S_FLIP) |
| ireg |= D7S_FLIP; |
| else |
| ireg &= ~D7S_FLIP; |
| } |
| writeb(ireg, p->regs); |
| break; |
| |
| case D7SIOCRD: |
| /* retrieve device register values |
| * NOTE: Solaris implementation returns D7S_FLIP bit |
| * as toggled by user, even though it does not honor it. |
| * This driver will not misinform you about the state |
| * of your hardware while in sol_compat mode |
| */ |
| if (put_user(regs, (int __user *) arg)) { |
| error = -EFAULT; |
| break; |
| } |
| break; |
| |
| case D7SIOCTM: |
| /* toggle device mode-- flip display orientation */ |
| regs ^= D7S_FLIP; |
| writeb(regs, p->regs); |
| break; |
| } |
| mutex_unlock(&d7s_mutex); |
| |
| return error; |
| } |
| |
| static const struct file_operations d7s_fops = { |
| .owner = THIS_MODULE, |
| .unlocked_ioctl = d7s_ioctl, |
| .compat_ioctl = d7s_ioctl, |
| .open = d7s_open, |
| .release = d7s_release, |
| .llseek = noop_llseek, |
| }; |
| |
| static struct miscdevice d7s_miscdev = { |
| .minor = D7S_MINOR, |
| .name = DRIVER_NAME, |
| .fops = &d7s_fops |
| }; |
| |
| static int d7s_probe(struct platform_device *op) |
| { |
| struct device_node *opts; |
| int err = -EINVAL; |
| struct d7s *p; |
| u8 regs; |
| |
| if (d7s_device) |
| goto out; |
| |
| p = devm_kzalloc(&op->dev, sizeof(*p), GFP_KERNEL); |
| err = -ENOMEM; |
| if (!p) |
| goto out; |
| |
| p->regs = of_ioremap(&op->resource[0], 0, sizeof(u8), "d7s"); |
| if (!p->regs) { |
| printk(KERN_ERR PFX "Cannot map chip registers\n"); |
| goto out_free; |
| } |
| |
| err = misc_register(&d7s_miscdev); |
| if (err) { |
| printk(KERN_ERR PFX "Unable to acquire miscdevice minor %i\n", |
| D7S_MINOR); |
| goto out_iounmap; |
| } |
| |
| /* OBP option "d7s-flipped?" is honored as default for the |
| * device, and reset default when detached |
| */ |
| regs = readb(p->regs); |
| opts = of_find_node_by_path("/options"); |
| if (opts && |
| of_get_property(opts, "d7s-flipped?", NULL)) |
| p->flipped = true; |
| |
| if (p->flipped) |
| regs |= D7S_FLIP; |
| else |
| regs &= ~D7S_FLIP; |
| |
| writeb(regs, p->regs); |
| |
| printk(KERN_INFO PFX "7-Segment Display%s at [%s:0x%llx] %s\n", |
| op->dev.of_node->full_name, |
| (regs & D7S_FLIP) ? " (FLIPPED)" : "", |
| op->resource[0].start, |
| sol_compat ? "in sol_compat mode" : ""); |
| |
| dev_set_drvdata(&op->dev, p); |
| d7s_device = p; |
| err = 0; |
| of_node_put(opts); |
| |
| out: |
| return err; |
| |
| out_iounmap: |
| of_iounmap(&op->resource[0], p->regs, sizeof(u8)); |
| |
| out_free: |
| goto out; |
| } |
| |
| static int d7s_remove(struct platform_device *op) |
| { |
| struct d7s *p = dev_get_drvdata(&op->dev); |
| u8 regs = readb(p->regs); |
| |
| /* Honor OBP d7s-flipped? unless operating in solaris-compat mode */ |
| if (sol_compat) { |
| if (p->flipped) |
| regs |= D7S_FLIP; |
| else |
| regs &= ~D7S_FLIP; |
| writeb(regs, p->regs); |
| } |
| |
| misc_deregister(&d7s_miscdev); |
| of_iounmap(&op->resource[0], p->regs, sizeof(u8)); |
| |
| return 0; |
| } |
| |
| static const struct of_device_id d7s_match[] = { |
| { |
| .name = "display7seg", |
| }, |
| {}, |
| }; |
| MODULE_DEVICE_TABLE(of, d7s_match); |
| |
| static struct platform_driver d7s_driver = { |
| .driver = { |
| .name = DRIVER_NAME, |
| .of_match_table = d7s_match, |
| }, |
| .probe = d7s_probe, |
| .remove = d7s_remove, |
| }; |
| |
| module_platform_driver(d7s_driver); |