/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include 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; unsigned long timeout; long ret; if (i2c->irq) { ret = wait_event_timeout(i2c->wait, i2c->algo_data.read_byte(i2c, I2C_PCA_CON) & I2C_PCA_CON_SI, i2c->adap.timeout); } else { /* Do polling */ timeout = jiffies + i2c->adap.timeout; do { ret = time_before(jiffies, timeout); if (i2c->algo_data.read_byte(i2c, I2C_PCA_CON) & I2C_PCA_CON_SI) break; udelay(100); } while (ret); } return ret > 0; } 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(&i2c->wait); return IRQ_HANDLED; } static int 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, resource_size(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, resource_size(res)); if (!i2c->reg_base) { ret = -ENOMEM; goto e_remap; } i2c->io_base = res->start; i2c->io_size = resource_size(res); i2c->irq = irq; i2c->adap.nr = pdev->id; i2c->adap.owner = THIS_MODULE; snprintf(i2c->adap.name, sizeof(i2c->adap.name), "PCA9564/PCA9665 at 0x%08lx", (unsigned long) res->start); i2c->adap.algo_data = &i2c->algo_data; i2c->adap.dev.parent = &pdev->dev; if (platform_data) { i2c->adap.timeout = platform_data->timeout; i2c->algo_data.i2c_clock = platform_data->i2c_clock_speed; i2c->gpio = platform_data->gpio; } else { i2c->adap.timeout = HZ; i2c->algo_data.i2c_clock = 59000; i2c->gpio = -1; } i2c->algo_data.data = i2c; i2c->algo_data.wait_for_completion = i2c_pca_pf_waitforcompletion; i2c->algo_data.reset_chip = i2c_pca_pf_dummyreset; 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; } /* 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, pdev->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, resource_size(res)); e_print: printk(KERN_ERR "Registering PCA9564/PCA9665 FAILED! (%d)\n", ret); return ret; } static int i2c_pca_pf_remove(struct platform_device *pdev) { struct i2c_pca_pf_data *i2c = platform_get_drvdata(pdev); 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 = i2c_pca_pf_remove, .driver = { .name = "i2c-pca-platform", .owner = THIS_MODULE, }, }; module_platform_driver(i2c_pca_pf_driver); MODULE_AUTHOR("Wolfram Sang "); MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver"); MODULE_LICENSE("GPL");