--- /dev/null
+/*
+ * i2c_pca_platform.c
+ *
+ * Platform driver for the PCA9564 I2C controller.
+ *
+ * Copyright (C) 2008 Pengutronix
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/i2c-algo-pca.h>
+#include <linux/i2c-pca-platform.h>
+#include <linux/gpio.h>
+
+#include <asm/irq.h>
+#include <asm/io.h>
+
+#define res_len(r) ((r)->end - (r)->start + 1)
+
+struct i2c_pca_pf_data {
+ void __iomem *reg_base;
+ int irq; /* if 0, use polling */
+ int gpio;
+ wait_queue_head_t wait;
+ struct i2c_adapter adap;
+ struct i2c_algo_pca_data algo_data;
+ unsigned long io_base;
+ unsigned long io_size;
+};
+
+/* Read/Write functions for different register alignments */
+
+static int i2c_pca_pf_readbyte8(void *pd, int reg)
+{
+ struct i2c_pca_pf_data *i2c = pd;
+ return ioread8(i2c->reg_base + reg);
+}
+
+static int i2c_pca_pf_readbyte16(void *pd, int reg)
+{
+ struct i2c_pca_pf_data *i2c = pd;
+ return ioread8(i2c->reg_base + reg * 2);
+}
+
+static int i2c_pca_pf_readbyte32(void *pd, int reg)
+{
+ struct i2c_pca_pf_data *i2c = pd;
+ return ioread8(i2c->reg_base + reg * 4);
+}
+
+static void i2c_pca_pf_writebyte8(void *pd, int reg, int val)
+{
+ struct i2c_pca_pf_data *i2c = pd;
+ iowrite8(val, i2c->reg_base + reg);
+}
+
+static void i2c_pca_pf_writebyte16(void *pd, int reg, int val)
+{
+ struct i2c_pca_pf_data *i2c = pd;
+ iowrite8(val, i2c->reg_base + reg * 2);
+}
+
+static void i2c_pca_pf_writebyte32(void *pd, int reg, int val)
+{
+ struct i2c_pca_pf_data *i2c = pd;
+ iowrite8(val, i2c->reg_base + reg * 4);
+}
+
+
+static int i2c_pca_pf_waitforcompletion(void *pd)
+{
+ struct i2c_pca_pf_data *i2c = pd;
+ int ret = 0;
+
+ if (i2c->irq) {
+ ret = wait_event_interruptible(i2c->wait,
+ i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
+ & I2C_PCA_CON_SI);
+ } else {
+ /*
+ * Do polling...
+ * XXX: Could get stuck in extreme cases!
+ * Maybe add timeout, but using irqs is preferred anyhow.
+ */
+ while ((i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
+ & I2C_PCA_CON_SI) == 0)
+ udelay(100);
+ }
+
+ return ret;
+}
+
+static void i2c_pca_pf_dummyreset(void *pd)
+{
+ struct i2c_pca_pf_data *i2c = pd;
+ printk(KERN_WARNING "%s: No reset-pin found. Chip may get stuck!\n",
+ i2c->adap.name);
+}
+
+static void i2c_pca_pf_resetchip(void *pd)
+{
+ struct i2c_pca_pf_data *i2c = pd;
+
+ gpio_set_value(i2c->gpio, 0);
+ ndelay(100);
+ gpio_set_value(i2c->gpio, 1);
+}
+
+static irqreturn_t i2c_pca_pf_handler(int this_irq, void *dev_id)
+{
+ struct i2c_pca_pf_data *i2c = dev_id;
+
+ if ((i2c->algo_data.read_byte(i2c, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0)
+ return IRQ_NONE;
+
+ wake_up_interruptible(&i2c->wait);
+
+ return IRQ_HANDLED;
+}
+
+
+static int __devinit i2c_pca_pf_probe(struct platform_device *pdev)
+{
+ struct i2c_pca_pf_data *i2c;
+ struct resource *res;
+ struct i2c_pca9564_pf_platform_data *platform_data =
+ pdev->dev.platform_data;
+ int ret = 0;
+ int irq;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ irq = platform_get_irq(pdev, 0);
+ /* If irq is 0, we do polling. */
+
+ if (res == NULL) {
+ ret = -ENODEV;
+ goto e_print;
+ }
+
+ if (!request_mem_region(res->start, res_len(res), res->name)) {
+ ret = -ENOMEM;
+ goto e_print;
+ }
+
+ i2c = kzalloc(sizeof(struct i2c_pca_pf_data), GFP_KERNEL);
+ if (!i2c) {
+ ret = -ENOMEM;
+ goto e_alloc;
+ }
+
+ init_waitqueue_head(&i2c->wait);
+
+ i2c->reg_base = ioremap(res->start, res_len(res));
+ if (!i2c->reg_base) {
+ ret = -EIO;
+ goto e_remap;
+ }
+ i2c->io_base = res->start;
+ i2c->io_size = res_len(res);
+ i2c->irq = irq;
+
+ i2c->adap.nr = pdev->id >= 0 ? pdev->id : 0;
+ i2c->adap.owner = THIS_MODULE;
+ snprintf(i2c->adap.name, sizeof(i2c->adap.name), "PCA9564 at 0x%08lx",
+ (unsigned long) res->start);
+ i2c->adap.algo_data = &i2c->algo_data;
+ i2c->adap.dev.parent = &pdev->dev;
+ i2c->adap.timeout = platform_data->timeout;
+
+ i2c->algo_data.i2c_clock = platform_data->i2c_clock_speed;
+ i2c->algo_data.data = i2c;
+
+ switch (res->flags & IORESOURCE_MEM_TYPE_MASK) {
+ case IORESOURCE_MEM_32BIT:
+ i2c->algo_data.write_byte = i2c_pca_pf_writebyte32;
+ i2c->algo_data.read_byte = i2c_pca_pf_readbyte32;
+ break;
+ case IORESOURCE_MEM_16BIT:
+ i2c->algo_data.write_byte = i2c_pca_pf_writebyte16;
+ i2c->algo_data.read_byte = i2c_pca_pf_readbyte16;
+ break;
+ case IORESOURCE_MEM_8BIT:
+ default:
+ i2c->algo_data.write_byte = i2c_pca_pf_writebyte8;
+ i2c->algo_data.read_byte = i2c_pca_pf_readbyte8;
+ break;
+ }
+
+ i2c->algo_data.wait_for_completion = i2c_pca_pf_waitforcompletion;
+
+ i2c->gpio = platform_data->gpio;
+ i2c->algo_data.reset_chip = i2c_pca_pf_dummyreset;
+
+ /* Use gpio_is_valid() when in mainline */
+ if (i2c->gpio > -1) {
+ ret = gpio_request(i2c->gpio, i2c->adap.name);
+ if (ret == 0) {
+ gpio_direction_output(i2c->gpio, 1);
+ i2c->algo_data.reset_chip = i2c_pca_pf_resetchip;
+ } else {
+ printk(KERN_WARNING "%s: Registering gpio failed!\n",
+ i2c->adap.name);
+ i2c->gpio = ret;
+ }
+ }
+
+ if (irq) {
+ ret = request_irq(irq, i2c_pca_pf_handler,
+ IRQF_TRIGGER_FALLING, i2c->adap.name, i2c);
+ if (ret)
+ goto e_reqirq;
+ }
+
+ if (i2c_pca_add_numbered_bus(&i2c->adap) < 0) {
+ ret = -ENODEV;
+ goto e_adapt;
+ }
+
+ platform_set_drvdata(pdev, i2c);
+
+ printk(KERN_INFO "%s registered.\n", i2c->adap.name);
+
+ return 0;
+
+e_adapt:
+ if (irq)
+ free_irq(irq, i2c);
+e_reqirq:
+ if (i2c->gpio > -1)
+ gpio_free(i2c->gpio);
+
+ iounmap(i2c->reg_base);
+e_remap:
+ kfree(i2c);
+e_alloc:
+ release_mem_region(res->start, res_len(res));
+e_print:
+ printk(KERN_ERR "Registering PCA9564 FAILED! (%d)\n", ret);
+ return ret;
+}
+
+static int __devexit i2c_pca_pf_remove(struct platform_device *pdev)
+{
+ struct i2c_pca_pf_data *i2c = platform_get_drvdata(pdev);
+ platform_set_drvdata(pdev, NULL);
+
+ i2c_del_adapter(&i2c->adap);
+
+ if (i2c->irq)
+ free_irq(i2c->irq, i2c);
+
+ if (i2c->gpio > -1)
+ gpio_free(i2c->gpio);
+
+ iounmap(i2c->reg_base);
+ release_mem_region(i2c->io_base, i2c->io_size);
+ kfree(i2c);
+
+ return 0;
+}
+
+static struct platform_driver i2c_pca_pf_driver = {
+ .probe = i2c_pca_pf_probe,
+ .remove = __devexit_p(i2c_pca_pf_remove),
+ .driver = {
+ .name = "i2c-pca-platform",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init i2c_pca_pf_init(void)
+{
+ return platform_driver_register(&i2c_pca_pf_driver);
+}
+
+static void __exit i2c_pca_pf_exit(void)
+{
+ platform_driver_unregister(&i2c_pca_pf_driver);
+}
+
+MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>");
+MODULE_DESCRIPTION("I2C-PCA9564 platform driver");
+MODULE_LICENSE("GPL");
+
+module_init(i2c_pca_pf_init);
+module_exit(i2c_pca_pf_exit);
+
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff