diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-pca-platform.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-pca-platform.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-pca-platform.c b/drivers/i2c/busses/i2c-pca-platform.c new file mode 100644 index 000000000..f50afa8e3 --- /dev/null +++ b/drivers/i2c/busses/i2c-pca-platform.c @@ -0,0 +1,262 @@ +/* + * 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/slab.h> +#include <linux/delay.h> +#include <linux/jiffies.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/platform_data/i2c-pca-platform.h> +#include <linux/gpio/consumer.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_device.h> + +#include <asm/irq.h> + +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", 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 <kernel@pengutronix.de>"); +MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver"); +MODULE_LICENSE("GPL"); |