summaryrefslogtreecommitdiffstats
path: root/drivers/i2c/busses/i2c-elektor.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/i2c/busses/i2c-elektor.c')
-rw-r--r--drivers/i2c/busses/i2c-elektor.c321
1 files changed, 321 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-elektor.c b/drivers/i2c/busses/i2c-elektor.c
new file mode 100644
index 0000000000..b0f50dce9d
--- /dev/null
+++ b/drivers/i2c/busses/i2c-elektor.c
@@ -0,0 +1,321 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* ------------------------------------------------------------------------- */
+/* i2c-elektor.c i2c-hw access for PCF8584 style isa bus adaptes */
+/* ------------------------------------------------------------------------- */
+/* Copyright (C) 1995-97 Simon G. Vogl
+ 1998-99 Hans Berglund
+
+ */
+/* ------------------------------------------------------------------------- */
+
+/* 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 DEFINE_SPINLOCK(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)
+{
+ 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 void 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);
+ }
+}
+
+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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-03 15:51:20 +0000