/* * 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 #include #include struct i2c_pca_pf_data { void __iomem *reg_base; int irq; /* if 0, use polling */ struct gpio_desc *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; dev_warn(&i2c->adap.dev, "No reset-pin found. Chip may get stuck!\n"); } static void i2c_pca_pf_resetchip(void *pd) { struct i2c_pca_pf_data *i2c = pd; gpiod_set_value(i2c->gpio, 1); ndelay(100); gpiod_set_value(i2c->gpio, 0); } 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 = dev_get_platdata(&pdev->dev); struct device_node *np = pdev->dev.of_node; int ret = 0; int irq; irq = platform_get_irq(pdev, 0); /* If irq is 0, we do polling. */ if (irq < 0) irq = 0; i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL); if (!i2c) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); i2c->reg_base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(i2c->reg_base)) return PTR_ERR(i2c->reg_base); init_waitqueue_head(&i2c->wait); 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; i2c->adap.dev.of_node = np; i2c->gpio = devm_gpiod_get_optional(&pdev->dev, "reset-gpios", GPIOD_OUT_LOW); if (IS_ERR(i2c->gpio)) return PTR_ERR(i2c->gpio); i2c->adap.timeout = HZ; ret = device_property_read_u32(&pdev->dev, "clock-frequency", &i2c->algo_data.i2c_clock); if (ret) i2c->algo_data.i2c_clock = 59000; if (platform_data) { i2c->adap.timeout = platform_data->timeout; i2c->algo_data.i2c_clock = platform_data->i2c_clock_speed; } i2c->algo_data.data = i2c; i2c->algo_data.wait_for_completion = i2c_pca_pf_waitforcompletion; if (i2c->gpio) i2c->algo_data.reset_chip = i2c_pca_pf_resetchip; else 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; } if (irq) { ret = devm_request_irq(&pdev->dev, irq, i2c_pca_pf_handler, IRQF_TRIGGER_FALLING, pdev->name, i2c); if (ret) return ret; } ret = i2c_pca_add_numbered_bus(&i2c->adap); if (ret) return ret; platform_set_drvdata(pdev, i2c); dev_info(&pdev->dev, "registered.\n"); return 0; } 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); return 0; } #ifdef CONFIG_OF static const struct of_device_id i2c_pca_of_match_table[] = { { .compatible = "nxp,pca9564" }, { .compatible = "nxp,pca9665" }, {}, }; MODULE_DEVICE_TABLE(of, i2c_pca_of_match_table); #endif static struct platform_driver i2c_pca_pf_driver = { .probe = i2c_pca_pf_probe, .remove = i2c_pca_pf_remove, .driver = { .name = "i2c-pca-platform", .of_match_table = of_match_ptr(i2c_pca_of_match_table), }, }; module_platform_driver(i2c_pca_pf_driver); MODULE_AUTHOR("Wolfram Sang "); MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver"); MODULE_LICENSE("GPL");