diff options
| -rw-r--r-- | Documentation/devicetree/bindings/i2c/i2c-cbus-gpio.txt | 27 | ||||
| -rw-r--r-- | arch/arm/mach-omap2/board-n8x0.c | 42 | ||||
| -rw-r--r-- | drivers/i2c/busses/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/i2c/busses/Makefile | 1 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-cbus-gpio.c | 300 | ||||
| -rw-r--r-- | include/linux/platform_data/i2c-cbus-gpio.h | 27 |
6 files changed, 407 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-cbus-gpio.txt b/Documentation/devicetree/bindings/i2c/i2c-cbus-gpio.txt new file mode 100644 index 000000000000..8ce9cd2855b5 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-cbus-gpio.txt @@ -0,0 +1,27 @@ +Device tree bindings for i2c-cbus-gpio driver + +Required properties: + - compatible = "i2c-cbus-gpio"; + - gpios: clk, dat, sel + - #address-cells = <1>; + - #size-cells = <0>; + +Optional properties: + - child nodes conforming to i2c bus binding + +Example: + +i2c@0 { + compatible = "i2c-cbus-gpio"; + gpios = <&gpio 66 0 /* clk */ + &gpio 65 0 /* dat */ + &gpio 64 0 /* sel */ + >; + #address-cells = <1>; + #size-cells = <0>; + + retu-mfd: retu@1 { + compatible = "retu-mfd"; + reg = <0x1>; + }; +}; diff --git a/arch/arm/mach-omap2/board-n8x0.c b/arch/arm/mach-omap2/board-n8x0.c index d95f727ca39a..bbfd74263c42 100644 --- a/arch/arm/mach-omap2/board-n8x0.c +++ b/arch/arm/mach-omap2/board-n8x0.c @@ -16,10 +16,12 @@ #include <linux/gpio.h> #include <linux/init.h> #include <linux/io.h> +#include <linux/irq.h> #include <linux/stddef.h> #include <linux/i2c.h> #include <linux/spi/spi.h> #include <linux/usb/musb.h> +#include <linux/platform_data/i2c-cbus-gpio.h> #include <linux/platform_data/spi-omap2-mcspi.h> #include <linux/platform_data/mtd-onenand-omap2.h> #include <sound/tlv320aic3x.h> @@ -39,6 +41,45 @@ #define TUSB6010_GPIO_ENABLE 0 #define TUSB6010_DMACHAN 0x3f +#if defined(CONFIG_I2C_CBUS_GPIO) || defined(CONFIG_I2C_CBUS_GPIO_MODULE) +static struct i2c_cbus_platform_data n8x0_cbus_data = { + .clk_gpio = 66, + .dat_gpio = 65, + .sel_gpio = 64, +}; + +static struct platform_device n8x0_cbus_device = { + .name = "i2c-cbus-gpio", + .id = 3, + .dev = { + .platform_data = &n8x0_cbus_data, + }, +}; + +static struct i2c_board_info n8x0_i2c_board_info_3[] __initdata = { + { + I2C_BOARD_INFO("retu-mfd", 0x01), + }, +}; + +static void __init n8x0_cbus_init(void) +{ + const int retu_irq_gpio = 108; + + if (gpio_request_one(retu_irq_gpio, GPIOF_IN, "Retu IRQ")) + return; + irq_set_irq_type(gpio_to_irq(retu_irq_gpio), IRQ_TYPE_EDGE_RISING); + n8x0_i2c_board_info_3[0].irq = gpio_to_irq(retu_irq_gpio); + i2c_register_board_info(3, n8x0_i2c_board_info_3, + ARRAY_SIZE(n8x0_i2c_board_info_3)); + platform_device_register(&n8x0_cbus_device); +} +#else /* CONFIG_I2C_CBUS_GPIO */ +static void __init n8x0_cbus_init(void) +{ +} +#endif /* CONFIG_I2C_CBUS_GPIO */ + #if defined(CONFIG_USB_MUSB_TUSB6010) || defined(CONFIG_USB_MUSB_TUSB6010_MODULE) /* * Enable or disable power to TUSB6010. When enabling, turn on 3.3 V and @@ -677,6 +718,7 @@ static void __init n8x0_init_machine(void) gpmc_onenand_init(board_onenand_data); n8x0_mmc_init(); n8x0_usb_init(); + n8x0_cbus_init(); } MACHINE_START(NOKIA_N800, "Nokia N800") diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index e9df4612b7eb..e949edf644d4 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -337,6 +337,16 @@ config I2C_BLACKFIN_TWI_CLK_KHZ help The unit of the TWI clock is kHz. +config I2C_CBUS_GPIO + tristate "CBUS I2C driver" + depends on GENERIC_GPIO + help + Support for CBUS access using I2C API. Mostly relevant for Nokia + Internet Tablets (770, N800 and N810). + + This driver can also be built as a module. If so, the module + will be called i2c-cbus-gpio. + config I2C_CPM tristate "Freescale CPM1 or CPM2 (MPC8xx/826x)" depends on (CPM1 || CPM2) && OF_I2C diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 395b516ffa08..f9e3e0b5c827 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -31,6 +31,7 @@ obj-$(CONFIG_I2C_POWERMAC) += i2c-powermac.o obj-$(CONFIG_I2C_AT91) += i2c-at91.o obj-$(CONFIG_I2C_AU1550) += i2c-au1550.o obj-$(CONFIG_I2C_BLACKFIN_TWI) += i2c-bfin-twi.o +obj-$(CONFIG_I2C_CBUS_GPIO) += i2c-cbus-gpio.o obj-$(CONFIG_I2C_CPM) += i2c-cpm.o obj-$(CONFIG_I2C_DAVINCI) += i2c-davinci.o obj-$(CONFIG_I2C_DESIGNWARE_CORE) += i2c-designware-core.o diff --git a/drivers/i2c/busses/i2c-cbus-gpio.c b/drivers/i2c/busses/i2c-cbus-gpio.c new file mode 100644 index 000000000000..98386d659318 --- /dev/null +++ b/drivers/i2c/busses/i2c-cbus-gpio.c @@ -0,0 +1,300 @@ +/* + * CBUS I2C driver for Nokia Internet Tablets. + * + * Copyright (C) 2004-2010 Nokia Corporation + * + * Based on code written by Juha Yrjölä, David Weinehall, Mikko Ylinen and + * Felipe Balbi. Converted to I2C driver by Aaro Koskinen. + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file "COPYING" in the main directory of this + * archive for more details. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/io.h> +#include <linux/i2c.h> +#include <linux/gpio.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/delay.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of_gpio.h> +#include <linux/interrupt.h> +#include <linux/platform_device.h> +#include <linux/platform_data/i2c-cbus-gpio.h> + +/* + * Bit counts are derived from Nokia implementation. These should be checked + * if other CBUS implementations appear. + */ +#define CBUS_ADDR_BITS 3 +#define CBUS_REG_BITS 5 + +struct cbus_host { + spinlock_t lock; /* host lock */ + struct device *dev; + int clk_gpio; + int dat_gpio; + int sel_gpio; +}; + +/** + * cbus_send_bit - sends one bit over the bus + * @host: the host we're using + * @bit: one bit of information to send + */ +static void cbus_send_bit(struct cbus_host *host, unsigned bit) +{ + gpio_set_value(host->dat_gpio, bit ? 1 : 0); + gpio_set_value(host->clk_gpio, 1); + gpio_set_value(host->clk_gpio, 0); +} + +/** + * cbus_send_data - sends @len amount of data over the bus + * @host: the host we're using + * @data: the data to send + * @len: size of the transfer + */ +static void cbus_send_data(struct cbus_host *host, unsigned data, unsigned len) +{ + int i; + + for (i = len; i > 0; i--) + cbus_send_bit(host, data & (1 << (i - 1))); +} + +/** + * cbus_receive_bit - receives one bit from the bus + * @host: the host we're using + */ +static int cbus_receive_bit(struct cbus_host *host) +{ + int ret; + + gpio_set_value(host->clk_gpio, 1); + ret = gpio_get_value(host->dat_gpio); + gpio_set_value(host->clk_gpio, 0); + return ret; +} + +/** + * cbus_receive_word - receives 16-bit word from the bus + * @host: the host we're using + */ +static int cbus_receive_word(struct cbus_host *host) +{ + int ret = 0; + int i; + + for (i = 16; i > 0; i--) { + int bit = cbus_receive_bit(host); + + if (bit < 0) + return bit; + + if (bit) + ret |= 1 << (i - 1); + } + return ret; +} + +/** + * cbus_transfer - transfers data over the bus + * @host: the host we're using + * @rw: read/write flag + * @dev: device address + * @reg: register address + * @data: if @rw == I2C_SBUS_WRITE data to send otherwise 0 + */ +static int cbus_transfer(struct cbus_host *host, char rw, unsigned dev, + unsigned reg, unsigned data) +{ + unsigned long flags; + int ret; + + /* We don't want interrupts disturbing our transfer */ + spin_lock_irqsave(&host->lock, flags); + + /* Reset state and start of transfer, SEL stays down during transfer */ + gpio_set_value(host->sel_gpio, 0); + + /* Set the DAT pin to output */ + gpio_direction_output(host->dat_gpio, 1); + + /* Send the device address */ + cbus_send_data(host, dev, CBUS_ADDR_BITS); + + /* Send the rw flag */ + cbus_send_bit(host, rw == I2C_SMBUS_READ); + + /* Send the register address */ + cbus_send_data(host, reg, CBUS_REG_BITS); + + if (rw == I2C_SMBUS_WRITE) { + cbus_send_data(host, data, 16); + ret = 0; + } else { + ret = gpio_direction_input(host->dat_gpio); + if (ret) { + dev_dbg(host->dev, "failed setting direction\n"); + goto out; + } + gpio_set_value(host->clk_gpio, 1); + + ret = cbus_receive_word(host); + if (ret < 0) { + dev_dbg(host->dev, "failed receiving data\n"); + goto out; + } + } + + /* Indicate end of transfer, SEL goes up until next transfer */ + gpio_set_value(host->sel_gpio, 1); + gpio_set_value(host->clk_gpio, 1); + gpio_set_value(host->clk_gpio, 0); + +out: + spin_unlock_irqrestore(&host->lock, flags); + + return ret; +} + +static int cbus_i2c_smbus_xfer(struct i2c_adapter *adapter, + u16 addr, + unsigned short flags, + char read_write, + u8 command, + int size, + union i2c_smbus_data *data) +{ + struct cbus_host *chost = i2c_get_adapdata(adapter); + int ret; + + if (size != I2C_SMBUS_WORD_DATA) + return -EINVAL; + + ret = cbus_transfer(chost, read_write == I2C_SMBUS_READ, addr, + command, data->word); + if (ret < 0) + return ret; + + if (read_write == I2C_SMBUS_READ) + data->word = ret; + + return 0; +} + +static u32 cbus_i2c_func(struct i2c_adapter *adapter) +{ + return I2C_FUNC_SMBUS_READ_WORD_DATA | I2C_FUNC_SMBUS_WRITE_WORD_DATA; +} + +static const struct i2c_algorithm cbus_i2c_algo = { + .smbus_xfer = cbus_i2c_smbus_xfer, + .functionality = cbus_i2c_func, +}; + +static int cbus_i2c_remove(struct platform_device *pdev) +{ + struct i2c_adapter *adapter = platform_get_drvdata(pdev); + + return i2c_del_adapter(adapter); +} + +static int cbus_i2c_probe(struct platform_device *pdev) +{ + struct i2c_adapter *adapter; + struct cbus_host *chost; + int ret; + + adapter = devm_kzalloc(&pdev->dev, sizeof(struct i2c_adapter), + GFP_KERNEL); + if (!adapter) + return -ENOMEM; + + chost = devm_kzalloc(&pdev->dev, sizeof(*chost), GFP_KERNEL); + if (!chost) + return -ENOMEM; + + if (pdev->dev.of_node) { + struct device_node *dnode = pdev->dev.of_node; + if (of_gpio_count(dnode) != 3) + return -ENODEV; + chost->clk_gpio = of_get_gpio(dnode, 0); + chost->dat_gpio = of_get_gpio(dnode, 1); + chost->sel_gpio = of_get_gpio(dnode, 2); + } else if (pdev->dev.platform_data) { + struct i2c_cbus_platform_data *pdata = pdev->dev.platform_data; + chost->clk_gpio = pdata->clk_gpio; + chost->dat_gpio = pdata->dat_gpio; + chost->sel_gpio = pdata->sel_gpio; + } else { + return -ENODEV; + } + + adapter->owner = THIS_MODULE; + adapter->class = I2C_CLASS_HWMON; + adapter->dev.parent = &pdev->dev; + adapter->nr = pdev->id; + adapter->timeout = HZ; + adapter->algo = &cbus_i2c_algo; + strlcpy(adapter->name, "CBUS I2C adapter", sizeof(adapter->name)); + + spin_lock_init(&chost->lock); + chost->dev = &pdev->dev; + + ret = devm_gpio_request_one(&pdev->dev, chost->clk_gpio, + GPIOF_OUT_INIT_LOW, "CBUS clk"); + if (ret) + return ret; + + ret = devm_gpio_request_one(&pdev->dev, chost->dat_gpio, GPIOF_IN, + "CBUS data"); + if (ret) + return ret; + + ret = devm_gpio_request_one(&pdev->dev, chost->sel_gpio, + GPIOF_OUT_INIT_HIGH, "CBUS sel"); + if (ret) + return ret; + + i2c_set_adapdata(adapter, chost); + platform_set_drvdata(pdev, adapter); + + return i2c_add_numbered_adapter(adapter); +} + +#if defined(CONFIG_OF) +static const struct of_device_id i2c_cbus_dt_ids[] = { + { .compatible = "i2c-cbus-gpio", }, + { } +}; +MODULE_DEVICE_TABLE(of, i2c_cbus_dt_ids); +#endif + +static struct platform_driver cbus_i2c_driver = { + .probe = cbus_i2c_probe, + .remove = cbus_i2c_remove, + .driver = { + .owner = THIS_MODULE, + .name = "i2c-cbus-gpio", + }, +}; +module_platform_driver(cbus_i2c_driver); + +MODULE_ALIAS("platform:i2c-cbus-gpio"); +MODULE_DESCRIPTION("CBUS I2C driver"); +MODULE_AUTHOR("Juha Yrjölä"); +MODULE_AUTHOR("David Weinehall"); +MODULE_AUTHOR("Mikko Ylinen"); +MODULE_AUTHOR("Felipe Balbi"); +MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/platform_data/i2c-cbus-gpio.h b/include/linux/platform_data/i2c-cbus-gpio.h new file mode 100644 index 000000000000..6faa992a9502 --- /dev/null +++ b/include/linux/platform_data/i2c-cbus-gpio.h @@ -0,0 +1,27 @@ +/* + * i2c-cbus-gpio.h - CBUS I2C platform_data definition + * + * Copyright (C) 2004-2009 Nokia Corporation + * + * Written by Felipe Balbi and Aaro Koskinen. + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file "COPYING" in the main directory of this + * archive for more details. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef __INCLUDE_LINUX_I2C_CBUS_GPIO_H +#define __INCLUDE_LINUX_I2C_CBUS_GPIO_H + +struct i2c_cbus_platform_data { + int dat_gpio; + int clk_gpio; + int sel_gpio; +}; + +#endif /* __INCLUDE_LINUX_I2C_CBUS_GPIO_H */ |
