diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-elektor.c')
-rw-r--r-- | drivers/i2c/busses/i2c-elektor.c | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-elektor.c b/drivers/i2c/busses/i2c-elektor.c new file mode 100644 index 000000000..5416003e0 --- /dev/null +++ b/drivers/i2c/busses/i2c-elektor.c @@ -0,0 +1,331 @@ +/* ------------------------------------------------------------------------- */ +/* i2c-elektor.c i2c-hw access for PCF8584 style isa bus adaptes */ +/* ------------------------------------------------------------------------- */ +/* Copyright (C) 1995-97 Simon G. Vogl + 1998-99 Hans Berglund + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. */ +/* ------------------------------------------------------------------------- */ + +/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and even + Frodo Looijaard <frodol@dds.nl> */ + +/* Partially rewriten by Oleg I. Vdovikin for mmapped support of + for Alpha Processor Inc. UP-2000(+) boards */ + +#include <linux/kernel.h> +#include <linux/ioport.h> +#include <linux/module.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/pci.h> +#include <linux/wait.h> + +#include <linux/isa.h> +#include <linux/i2c.h> +#include <linux/i2c-algo-pcf.h> +#include <linux/io.h> + +#include <asm/irq.h> + +#include "../algos/i2c-algo-pcf.h" + +#define DEFAULT_BASE 0x330 + +static int base; +static u8 __iomem *base_iomem; + +static int irq; +static int clock = 0x1c; +static int own = 0x55; +static int mmapped; + +/* vdovikin: removed static struct i2c_pcf_isa gpi; code - + this module in real supports only one device, due to missing arguments + in some functions, called from the algo-pcf module. Sometimes it's + need to be rewriten - but for now just remove this for simpler reading */ + +static wait_queue_head_t pcf_wait; +static int pcf_pending; +static spinlock_t lock; + +static struct i2c_adapter pcf_isa_ops; + +/* ----- local functions ---------------------------------------------- */ + +static void pcf_isa_setbyte(void *data, int ctl, int val) +{ + u8 __iomem *address = ctl ? (base_iomem + 1) : base_iomem; + + /* enable irq if any specified for serial operation */ + if (ctl && irq && (val & I2C_PCF_ESO)) { + val |= I2C_PCF_ENI; + } + + pr_debug("%s: Write %p 0x%02X\n", pcf_isa_ops.name, address, val); + iowrite8(val, address); +#ifdef __alpha__ + /* API UP2000 needs some hardware fudging to make the write stick */ + iowrite8(val, address); +#endif +} + +static int pcf_isa_getbyte(void *data, int ctl) +{ + u8 __iomem *address = ctl ? (base_iomem + 1) : base_iomem; + int val = ioread8(address); + + pr_debug("%s: Read %p 0x%02X\n", pcf_isa_ops.name, address, val); + return (val); +} + +static int pcf_isa_getown(void *data) +{ + return (own); +} + + +static int pcf_isa_getclock(void *data) +{ + return (clock); +} + +static void pcf_isa_waitforpin(void *data) +{ + DEFINE_WAIT(wait); + int timeout = 2; + unsigned long flags; + + if (irq > 0) { + spin_lock_irqsave(&lock, flags); + if (pcf_pending == 0) { + spin_unlock_irqrestore(&lock, flags); + prepare_to_wait(&pcf_wait, &wait, TASK_INTERRUPTIBLE); + if (schedule_timeout(timeout*HZ)) { + spin_lock_irqsave(&lock, flags); + if (pcf_pending == 1) { + pcf_pending = 0; + } + spin_unlock_irqrestore(&lock, flags); + } + finish_wait(&pcf_wait, &wait); + } else { + pcf_pending = 0; + spin_unlock_irqrestore(&lock, flags); + } + } else { + udelay(100); + } +} + + +static irqreturn_t pcf_isa_handler(int this_irq, void *dev_id) { + spin_lock(&lock); + pcf_pending = 1; + spin_unlock(&lock); + wake_up_interruptible(&pcf_wait); + return IRQ_HANDLED; +} + + +static int pcf_isa_init(void) +{ + spin_lock_init(&lock); + if (!mmapped) { + if (!request_region(base, 2, pcf_isa_ops.name)) { + printk(KERN_ERR "%s: requested I/O region (%#x:2) is " + "in use\n", pcf_isa_ops.name, base); + return -ENODEV; + } + base_iomem = ioport_map(base, 2); + if (!base_iomem) { + printk(KERN_ERR "%s: remap of I/O region %#x failed\n", + pcf_isa_ops.name, base); + release_region(base, 2); + return -ENODEV; + } + } else { + if (!request_mem_region(base, 2, pcf_isa_ops.name)) { + printk(KERN_ERR "%s: requested memory region (%#x:2) " + "is in use\n", pcf_isa_ops.name, base); + return -ENODEV; + } + base_iomem = ioremap(base, 2); + if (base_iomem == NULL) { + printk(KERN_ERR "%s: remap of memory region %#x " + "failed\n", pcf_isa_ops.name, base); + release_mem_region(base, 2); + return -ENODEV; + } + } + pr_debug("%s: registers %#x remapped to %p\n", pcf_isa_ops.name, base, + base_iomem); + + if (irq > 0) { + if (request_irq(irq, pcf_isa_handler, 0, pcf_isa_ops.name, + NULL) < 0) { + printk(KERN_ERR "%s: Request irq%d failed\n", + pcf_isa_ops.name, irq); + irq = 0; + } else + enable_irq(irq); + } + return 0; +} + +/* ------------------------------------------------------------------------ + * Encapsulate the above functions in the correct operations structure. + * This is only done when more than one hardware adapter is supported. + */ +static struct i2c_algo_pcf_data pcf_isa_data = { + .setpcf = pcf_isa_setbyte, + .getpcf = pcf_isa_getbyte, + .getown = pcf_isa_getown, + .getclock = pcf_isa_getclock, + .waitforpin = pcf_isa_waitforpin, +}; + +static struct i2c_adapter pcf_isa_ops = { + .owner = THIS_MODULE, + .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, + .algo_data = &pcf_isa_data, + .name = "i2c-elektor", +}; + +static int elektor_match(struct device *dev, unsigned int id) +{ +#ifdef __alpha__ + /* check to see we have memory mapped PCF8584 connected to the + Cypress cy82c693 PCI-ISA bridge as on UP2000 board */ + if (base == 0) { + struct pci_dev *cy693_dev; + + cy693_dev = pci_get_device(PCI_VENDOR_ID_CONTAQ, + PCI_DEVICE_ID_CONTAQ_82C693, NULL); + if (cy693_dev) { + unsigned char config; + /* yeap, we've found cypress, let's check config */ + if (!pci_read_config_byte(cy693_dev, 0x47, &config)) { + + dev_dbg(dev, "found cy82c693, config " + "register 0x47 = 0x%02x\n", config); + + /* UP2000 board has this register set to 0xe1, + but the most significant bit as seems can be + reset during the proper initialisation + sequence if guys from API decides to do that + (so, we can even enable Tsunami Pchip + window for the upper 1 Gb) */ + + /* so just check for ROMCS at 0xe0000, + ROMCS enabled for writes + and external XD Bus buffer in use. */ + if ((config & 0x7f) == 0x61) { + /* seems to be UP2000 like board */ + base = 0xe0000; + mmapped = 1; + /* UP2000 drives ISA with + 8.25 MHz (PCI/4) clock + (this can be read from cypress) */ + clock = I2C_PCF_CLK | I2C_PCF_TRNS90; + dev_info(dev, "found API UP2000 like " + "board, will probe PCF8584 " + "later\n"); + } + } + pci_dev_put(cy693_dev); + } + } +#endif + + /* sanity checks for mmapped I/O */ + if (mmapped && base < 0xc8000) { + dev_err(dev, "incorrect base address (%#x) specified " + "for mmapped I/O\n", base); + return 0; + } + + if (base == 0) { + base = DEFAULT_BASE; + } + return 1; +} + +static int elektor_probe(struct device *dev, unsigned int id) +{ + init_waitqueue_head(&pcf_wait); + if (pcf_isa_init()) + return -ENODEV; + pcf_isa_ops.dev.parent = dev; + if (i2c_pcf_add_bus(&pcf_isa_ops) < 0) + goto fail; + + dev_info(dev, "found device at %#x\n", base); + + return 0; + + fail: + if (irq > 0) { + disable_irq(irq); + free_irq(irq, NULL); + } + + if (!mmapped) { + ioport_unmap(base_iomem); + release_region(base, 2); + } else { + iounmap(base_iomem); + release_mem_region(base, 2); + } + return -ENODEV; +} + +static int elektor_remove(struct device *dev, unsigned int id) +{ + i2c_del_adapter(&pcf_isa_ops); + + if (irq > 0) { + disable_irq(irq); + free_irq(irq, NULL); + } + + if (!mmapped) { + ioport_unmap(base_iomem); + release_region(base, 2); + } else { + iounmap(base_iomem); + release_mem_region(base, 2); + } + + return 0; +} + +static struct isa_driver i2c_elektor_driver = { + .match = elektor_match, + .probe = elektor_probe, + .remove = elektor_remove, + .driver = { + .owner = THIS_MODULE, + .name = "i2c-elektor", + }, +}; + +MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>"); +MODULE_DESCRIPTION("I2C-Bus adapter routines for PCF8584 ISA bus adapter"); +MODULE_LICENSE("GPL"); + +module_param_hw(base, int, ioport_or_iomem, 0); +module_param_hw(irq, int, irq, 0); +module_param(clock, int, 0); +module_param(own, int, 0); +module_param_hw(mmapped, int, other, 0); +module_isa_driver(i2c_elektor_driver, 1); |