Re: [RFC PATCH] i2c: new bus driver for efm32

["Uwe Kleine-König" <u.kleine-koenig-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>]

On Mon, Feb 10, 2014 at 11:19:58AM +0100, Uwe Kleine-König wrote:
> This was tested on a EFM32GG-DK3750 devboard that has a temperature
> sensor and an eeprom on its i2c bus.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
ping

Thanks
Uwe

> ---
> Hello,
> 
> there are two places marked with a triple-X where I don't know if I did
> it right. The one is "Do I need to protect from .master_xfer being
> called again before the previous call returned?" The other is what to
> return in the .functionality callback.
> 
> Also note there is a matching entry in MAINTAINERS for "ARM/ENERGY MICRO
> (SILICON LABS) EFM32 SUPPORT".
> 
> Best regards
> Uwe
> 
>  drivers/i2c/busses/Kconfig              |   7 +
>  drivers/i2c/busses/Makefile             |   1 +
>  drivers/i2c/busses/i2c-efm32.c          | 527 ++++++++++++++++++++++++++++++++
>  include/linux/platform_data/efm32-i2c.h |  15 +
>  4 files changed, 550 insertions(+)
>  create mode 100644 drivers/i2c/busses/i2c-efm32.c
>  create mode 100644 include/linux/platform_data/efm32-i2c.h
> 
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index f5ed03164d86..7322ff0c4c60 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -432,6 +432,13 @@ config I2C_DESIGNWARE_PCI
>  	  This driver can also be built as a module.  If so, the module
>  	  will be called i2c-designware-pci.
>  
> +config I2C_EFM32
> +	tristate "EFM32 I2C controller"
> +	depends on OF && (ARCH_EFM32 || COMPILE_TEST)
> +	help
> +	  This driver supports the i2c block found in Energy Micro's EFM32
> +	  SoCs.
> +
>  config I2C_EG20T
>  	tristate "Intel EG20T PCH/LAPIS Semicon IOH(ML7213/ML7223/ML7831) I2C"
>  	depends on PCI
> diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
> index a08931fe73e1..2a56ab181851 100644
> --- a/drivers/i2c/busses/Makefile
> +++ b/drivers/i2c/busses/Makefile
> @@ -41,6 +41,7 @@ obj-$(CONFIG_I2C_DESIGNWARE_PLATFORM)	+= i2c-designware-platform.o
>  i2c-designware-platform-objs := i2c-designware-platdrv.o
>  obj-$(CONFIG_I2C_DESIGNWARE_PCI)	+= i2c-designware-pci.o
>  i2c-designware-pci-objs := i2c-designware-pcidrv.o
> +obj-$(CONFIG_I2C_EFM32)		+= i2c-efm32.o
>  obj-$(CONFIG_I2C_EG20T)		+= i2c-eg20t.o
>  obj-$(CONFIG_I2C_EXYNOS5)	+= i2c-exynos5.o
>  obj-$(CONFIG_I2C_GPIO)		+= i2c-gpio.o
> diff --git a/drivers/i2c/busses/i2c-efm32.c b/drivers/i2c/busses/i2c-efm32.c
> new file mode 100644
> index 000000000000..9e860abcab63
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-efm32.c
> @@ -0,0 +1,527 @@
> +/*
> + * Copyright (C) 2014 Uwe Kleine-Koenig for 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/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/i2c.h>
> +#include <linux/io.h>
> +#include <linux/interrupt.h>
> +#include <linux/err.h>
> +#include <linux/clk.h>
> +#include <linux/platform_data/efm32-i2c.h>
> +
> +#define DRIVER_NAME "efm32-i2c"
> +
> +#define MASK_VAL(mask, val)		((val << __ffs(mask)) & mask)
> +
> +#define REG_CTRL		0x00
> +#define REG_CTRL_EN			0x00001
> +#define REG_CTRL_SLAVE			0x00002
> +#define REG_CTRL_AUTOACK		0x00004
> +#define REG_CTRL_AUTOSE			0x00008
> +#define REG_CTRL_AUTOSN			0x00010
> +#define REG_CTRL_ARBDIS			0x00020
> +#define REG_CTRL_GCAMEN			0x00040
> +#define REG_CTRL_CLHR__MASK		0x00300
> +#define REG_CTRL_BITO__MASK		0x03000
> +#define REG_CTRL_BITO_OFF		0x00000
> +#define REG_CTRL_BITO_40PCC		0x01000
> +#define REG_CTRL_BITO_80PCC		0x02000
> +#define REG_CTRL_BITO_160PCC		0x03000
> +#define REG_CTRL_GIBITO			0x08000
> +#define REG_CTRL_CLTO__MASK		0x70000
> +#define REG_CTRL_CLTO_OFF		0x00000
> +
> +#define REG_CMD			0x04
> +#define REG_CMD_START			0x00001
> +#define REG_CMD_STOP			0x00002
> +#define REG_CMD_ACK			0x00004
> +#define REG_CMD_NACK			0x00008
> +#define REG_CMD_CONT			0x00010
> +#define REG_CMD_ABORT			0x00020
> +#define REG_CMD_CLEARTX			0x00040
> +#define REG_CMD_CLEARPC			0x00080
> +
> +#define REG_STATE		0x08
> +#define REG_STATE_BUSY			0x00001
> +#define REG_STATE_MASTER		0x00002
> +#define REG_STATE_TRANSMITTER		0x00004
> +#define REG_STATE_NACKED		0x00008
> +#define REG_STATE_BUSHOLD		0x00010
> +#define REG_STATE_STATE__MASK		0x000e0
> +#define REG_STATE_STATE_IDLE		0x00000
> +#define REG_STATE_STATE_WAIT		0x00020
> +#define REG_STATE_STATE_START		0x00040
> +#define REG_STATE_STATE_ADDR		0x00060
> +#define REG_STATE_STATE_ADDRACK		0x00080
> +#define REG_STATE_STATE_DATA		0x000a0
> +#define REG_STATE_STATE_DATAACK		0x000c0
> +
> +#define REG_STATUS		0x0c
> +#define REG_STATUS_PSTART		0x00001
> +#define REG_STATUS_PSTOP		0x00002
> +#define REG_STATUS_PACK			0x00004
> +#define REG_STATUS_PNACK		0x00008
> +#define REG_STATUS_PCONT		0x00010
> +#define REG_STATUS_PABORT		0x00020
> +#define REG_STATUS_TXC			0x00040
> +#define REG_STATUS_TXBL			0x00080
> +#define REG_STATUS_RXDATAV		0x00100
> +
> +#define REG_CLKDIV		0x10
> +#define REG_CLKDIV_DIV__MASK		0x001ff
> +#define REG_CLKDIV_DIV(div)		MASK_VAL(REG_CLKDIV_DIV__MASK, (div))
> +
> +#define REG_SADDR		0x14
> +#define REG_SADDRMASK		0x18
> +#define REG_RXDATA		0x1c
> +#define REG_RXDATAP		0x20
> +#define REG_TXDATA		0x24
> +#define REG_IF			0x28
> +#define REG_IF_START			0x00001
> +#define REG_IF_RSTART			0x00002
> +#define REG_IF_ADDR			0x00004
> +#define REG_IF_TXC			0x00008
> +#define REG_IF_TXBL			0x00010
> +#define REG_IF_RXDATAV			0x00020
> +#define REG_IF_ACK			0x00040
> +#define REG_IF_NACK			0x00080
> +#define REG_IF_MSTOP			0x00100
> +#define REG_IF_ARBLOST			0x00200
> +#define REG_IF_BUSERR			0x00400
> +#define REG_IF_BUSHOLD			0x00800
> +#define REG_IF_TXOF			0x01000
> +#define REG_IF_RXUF			0x02000
> +#define REG_IF_BITO			0x04000
> +#define REG_IF_CLTO			0x08000
> +#define REG_IF_SSTOP			0x10000
> +
> +#define REG_IFS			0x2c
> +#define REG_IFC			0x30
> +#define REG_IFC__MASK			0x1ffcf
> +
> +#define REG_IEN			0x34
> +
> +#define REG_ROUTE		0x38
> +#define REG_ROUTE_SDAPEN		0x00001
> +#define REG_ROUTE_SCLPEN		0x00002
> +#define REG_ROUTE_LOCATION__MASK	0x00700
> +#define REG_ROUTE_LOCATION(n)		MASK_VAL(REG_ROUTE_LOCATION__MASK, (n))
> +
> +struct efm32_i2c_ddata {
> +	struct i2c_adapter adapter;
> +	spinlock_t lock;
> +
> +	struct clk *clk;
> +	void __iomem *base;
> +	unsigned int irq;
> +	struct efm32_i2c_pdata pdata;
> +
> +	/* transfer data */
> +	struct completion done;
> +	struct i2c_msg *msgs;
> +	size_t num_msgs;
> +	size_t current_word, current_msg;
> +};
> +
> +static u32 efm32_i2c_read32(struct efm32_i2c_ddata *ddata, unsigned offset)
> +{
> +	return readl(ddata->base + offset);
> +}
> +
> +static void efm32_i2c_write32(struct efm32_i2c_ddata *ddata,
> +		unsigned offset, u32 value)
> +{
> +	writel(value, ddata->base + offset);
> +}
> +
> +static void efm32_i2c_send_next_msg(struct efm32_i2c_ddata *ddata)
> +{
> +	struct i2c_msg *cur_msg = &ddata->msgs[ddata->current_msg];
> +
> +	dev_dbg(&ddata->adapter.dev, "send msg %zu/%zu (addr = %x, flags = %x, if = %08x)\n",
> +			ddata->current_msg, ddata->num_msgs, cur_msg->addr,
> +			cur_msg->flags, efm32_i2c_read32(ddata, REG_IF));
> +	efm32_i2c_write32(ddata, REG_CMD, REG_CMD_START);
> +	efm32_i2c_write32(ddata, REG_TXDATA, cur_msg->addr << 1 |
> +			(cur_msg->flags & I2C_M_RD ? 1 : 0));
> +}
> +
> +static void efm32_i2c_send_next_byte(struct efm32_i2c_ddata *ddata)
> +{
> +	struct i2c_msg *cur_msg = &ddata->msgs[ddata->current_msg];
> +	dev_dbg(&ddata->adapter.dev, "%s, %zu %zu\n",
> +			__func__, ddata->current_word, cur_msg->len);
> +	if (ddata->current_word >= cur_msg->len) {
> +		/* cur_msg completely transferred */
> +		ddata->current_word = 0;
> +		ddata->current_msg += 1;
> +
> +		if (ddata->current_msg >= ddata->num_msgs) {
> +			dev_dbg(&ddata->adapter.dev, "Stop\n");
> +			efm32_i2c_write32(ddata, REG_CMD, REG_CMD_STOP);
> +			complete(&ddata->done);
> +		} else {
> +			efm32_i2c_send_next_msg(ddata);
> +		}
> +	} else {
> +		dev_dbg(&ddata->adapter.dev, "send byte %zu/%zu\n",
> +				ddata->current_word, cur_msg->len);
> +		efm32_i2c_write32(ddata, REG_TXDATA,
> +				cur_msg->buf[ddata->current_word++]);
> +	}
> +}
> +
> +static void efm32_i2c_recv_next_byte(struct efm32_i2c_ddata *ddata)
> +{
> +	struct i2c_msg *cur_msg = &ddata->msgs[ddata->current_msg];
> +
> +	cur_msg->buf[ddata->current_word] = efm32_i2c_read32(ddata, REG_RXDATA);
> +	dev_dbg(&ddata->adapter.dev, "recv byte %zu/%zu: 0x%02hhx\n",
> +			ddata->current_word, cur_msg->len, cur_msg->buf[ddata->current_word]);
> +	ddata->current_word += 1;
> +	if (ddata->current_word >= cur_msg->len) {
> +		/* cur_msg completely transferred */
> +		ddata->current_word = 0;
> +		ddata->current_msg += 1;
> +
> +		efm32_i2c_write32(ddata, REG_CMD, REG_CMD_NACK);
> +
> +		if (ddata->current_msg >= ddata->num_msgs) {
> +			efm32_i2c_write32(ddata, REG_CMD, REG_CMD_STOP);
> +			complete(&ddata->done);
> +		} else {
> +			efm32_i2c_send_next_msg(ddata);
> +		}
> +	} else {
> +		efm32_i2c_write32(ddata, REG_CMD, REG_CMD_ACK);
> +	}
> +}
> +
> +static irqreturn_t efm32_i2c_irq(int irq, void *dev_id)
> +{
> +	struct efm32_i2c_ddata *ddata = dev_id;
> +	struct i2c_msg *cur_msg = &ddata->msgs[ddata->current_msg];
> +	u32 irqflag = efm32_i2c_read32(ddata, REG_IF);
> +	u32 state = efm32_i2c_read32(ddata, REG_STATE);
> +
> +	dev_dbg(&ddata->adapter.dev, "irq: if: %08x, state: %08x, status: %08x\n",
> +			irqflag, state, efm32_i2c_read32(ddata, REG_STATUS));
> +	efm32_i2c_write32(ddata, REG_IFC, irqflag & REG_IFC__MASK);
> +
> +	switch (state & REG_STATE_STATE__MASK) {
> +	case REG_STATE_STATE_IDLE:
> +		/* arbitration lost? */
> +		complete(&ddata->done);
> +		break;
> +	case REG_STATE_STATE_WAIT:
> +		/* huh, this shouldn't happen */
> +		BUG();
> +		break;
> +	case REG_STATE_STATE_START:
> +		/* "caller" is expected to send an address */
> +		break;
> +	case REG_STATE_STATE_ADDR:
> +		/* wait for Ack or NAck of slave */
> +		break;
> +	case REG_STATE_STATE_ADDRACK:
> +		if (state & REG_STATE_NACKED) {
> +			efm32_i2c_write32(ddata, REG_CMD, REG_CMD_STOP);
> +			complete(&ddata->done);
> +		} else if (cur_msg->flags & I2C_M_RD) {
> +			/* wait for slave to send first data byte */
> +		} else {
> +			efm32_i2c_send_next_byte(ddata);
> +		}
> +		break;
> +	case REG_STATE_STATE_DATA:
> +		if (cur_msg->flags & I2C_M_RD) {
> +			efm32_i2c_recv_next_byte(ddata);
> +		} else {
> +			/* wait for Ack or Nack of slave */
> +		}
> +		break;
> +	case REG_STATE_STATE_DATAACK:
> +		if (state & REG_STATE_NACKED) {
> +			efm32_i2c_write32(ddata, REG_CMD, REG_CMD_STOP);
> +			complete(&ddata->done);
> +		} else {
> +			efm32_i2c_send_next_byte(ddata);
> +		}
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int efm32_i2c_master_xfer(struct i2c_adapter *adap,
> +		struct i2c_msg *msgs, int num)
> +{
> +	struct efm32_i2c_ddata *ddata = i2c_get_adapdata(adap);
> +	int ret = -EBUSY;
> +
> +	spin_lock_irq(&ddata->lock);
> +
> +	if (ddata->msgs)
> +		/*
> +		 * XXX: can .master_xfer be called when the previous is still
> +		 * running?
> +		 */
> +		goto out_unlock;
> +
> +	ddata->msgs = msgs;
> +	ddata->num_msgs = num;
> +	ddata->current_word = 0;
> +	ddata->current_msg = 0;
> +
> +	init_completion(&ddata->done);
> +
> +	dev_dbg(&ddata->adapter.dev, "state: %08x, status: %08x\n",
> +			efm32_i2c_read32(ddata, REG_STATE),
> +			efm32_i2c_read32(ddata, REG_STATUS));
> +
> +	efm32_i2c_send_next_msg(ddata);
> +
> +	spin_unlock_irq(&ddata->lock);
> +
> +	wait_for_completion(&ddata->done);
> +
> +	spin_lock_irq(&ddata->lock);
> +
> +	if (ddata->current_msg >= ddata->num_msgs)
> +		ret = ddata->num_msgs;
> +	else
> +		ret = -EIO;
> +
> +	ddata->msgs = NULL;
> +
> +out_unlock:
> +	spin_unlock_irq(&ddata->lock);
> +	return ret;
> +}
> +
> +static u32 efm32_i2c_functionality(struct i2c_adapter *adap)
> +{
> +	/* XXX: some more? */
> +	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
> +}
> +
> +static const struct i2c_algorithm efm32_i2c_algo = {
> +	.master_xfer = efm32_i2c_master_xfer,
> +	.functionality = efm32_i2c_functionality,
> +};
> +
> +static u32 efm32_i2c_get_configured_location(struct efm32_i2c_ddata *ddata)
> +{
> +	u32 reg = efm32_i2c_read32(ddata, REG_ROUTE);
> +
> +	return (reg & REG_ROUTE_LOCATION__MASK) >>
> +		__ffs(REG_ROUTE_LOCATION__MASK);
> +}
> +
> +static int efm32_i2c_probe_dt(struct platform_device *pdev,
> +		struct efm32_i2c_ddata *ddata)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	u32 location, frequency;
> +	int ret;
> +
> +	if (!np)
> +		return 1;
> +
> +	ret = of_property_read_u32(np, "location", &location);
> +	if (!ret) {
> +		dev_dbg(&pdev->dev, "using location %u\n", location);
> +	} else {
> +		/* default to location configured in hardware */
> +		location = efm32_i2c_get_configured_location(ddata);
> +
> +		dev_info(&pdev->dev, "fall back to location %u\n", location);
> +	}
> +
> +	ddata->pdata.location = location;
> +
> +	ret = of_property_read_u32(np, "clock-frequency", &frequency);
> +	if (!ret) {
> +		dev_dbg(&pdev->dev, "using frequency %u\n", frequency);
> +	} else {
> +		frequency = 100000;
> +		dev_info(&pdev->dev, "defaulting to 100 kHz\n");
> +	}
> +	ddata->pdata.frequency = frequency;
> +
> +	/* i2c core takes care about bus numbering using an alias */
> +	ddata->adapter.nr = -1;
> +
> +	return 0;
> +}
> +
> +static int efm32_i2c_probe(struct platform_device *pdev)
> +{
> +	struct efm32_i2c_ddata *ddata;
> +	struct resource *res;
> +	unsigned long rate;
> +	int ret;
> +	u32 clkdiv;
> +
> +	ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
> +	if (!ddata) {
> +		dev_dbg(&pdev->dev, "failed to allocate private data\n");
> +		return -ENOMEM;
> +	}
> +	platform_set_drvdata(pdev, ddata);
> +
> +	strlcpy(ddata->adapter.name, pdev->name, sizeof(ddata->adapter.name));
> +	ddata->adapter.owner = THIS_MODULE;
> +	ddata->adapter.algo = &efm32_i2c_algo;
> +	ddata->adapter.dev.parent = &pdev->dev;
> +	ddata->adapter.dev.of_node = pdev->dev.of_node;
> +	i2c_set_adapdata(&ddata->adapter, ddata);
> +
> +	spin_lock_init(&ddata->lock);
> +
> +	ddata->clk = devm_clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(ddata->clk)) {
> +		ret = PTR_ERR(ddata->clk);
> +		dev_err(&pdev->dev, "failed to get clock: %d\n", ret);
> +		return ret;
> +	}
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res) {
> +		dev_err(&pdev->dev, "failed to determine base address\n");
> +		return -ENODEV;
> +	}
> +
> +	if (resource_size(res) < 0x42) {
> +		dev_err(&pdev->dev, "memory resource too small\n");
> +		return -EINVAL;
> +	}
> +
> +	ddata->base = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(ddata->base))
> +		return PTR_ERR(ddata->base);
> +
> +	ret = platform_get_irq(pdev, 0);
> +	if (ret <= 0) {
> +		dev_err(&pdev->dev, "failed to get irq (%d)\n", ret);
> +		if (!ret)
> +			ret = -EINVAL;
> +		return ret;
> +	}
> +
> +	ddata->irq = ret;
> +
> +	ret = clk_prepare_enable(ddata->clk);
> +	if (ret < 0) {
> +		dev_err(&pdev->dev, "failed to enable clock (%d)\n", ret);
> +		return ret;
> +	}
> +
> +	ret = efm32_i2c_probe_dt(pdev, ddata);
> +	if (ret > 0) {
> +		/* not created by device tree */
> +		const struct efm32_i2c_pdata *pdata =
> +			dev_get_platdata(&pdev->dev);
> +
> +		if (pdata)
> +			ddata->pdata = *pdata;
> +		else {
> +			ddata->pdata.location =
> +				efm32_i2c_get_configured_location(ddata);
> +			ddata->pdata.frequency = 100000;
> +		}
> +
> +		ddata->adapter.nr = pdev->id;
> +	} else if (ret < 0) {
> +		goto err_disable_clk;
> +	}
> +
> +	rate = clk_get_rate(ddata->clk);
> +	if (!rate) {
> +		dev_err(&pdev->dev, "there is no input clock available\n");
> +		ret = -EIO;
> +		goto err_disable_clk;
> +	}
> +	clkdiv = DIV_ROUND_UP(rate, 8 * ddata->pdata.frequency) - 1;
> +	if (clkdiv >= 0x200) {
> +		dev_err(&pdev->dev,
> +				"input clock too fast (%lu) to divide down to bus freq (%lu)",
> +				rate, ddata->pdata.frequency);
> +		ret = -EIO;
> +		goto err_disable_clk;
> +	}
> +
> +	dev_dbg(&pdev->dev, "input clock = %lu, bus freq = %lu, clkdiv = %lu\n",
> +			rate, ddata->pdata.frequency, (unsigned long)clkdiv);
> +	efm32_i2c_write32(ddata, REG_CLKDIV, REG_CLKDIV_DIV(clkdiv));
> +
> +	efm32_i2c_write32(ddata, REG_ROUTE, REG_ROUTE_SDAPEN |
> +			REG_ROUTE_SCLPEN |
> +			REG_ROUTE_LOCATION(ddata->pdata.location));
> +
> +	efm32_i2c_write32(ddata, REG_CTRL, REG_CTRL_EN |
> +			REG_CTRL_BITO_160PCC | 0 * REG_CTRL_GIBITO);
> +
> +	efm32_i2c_write32(ddata, REG_IFC, REG_IFC__MASK);
> +	efm32_i2c_write32(ddata, REG_IEN, REG_IF_TXC | REG_IF_ACK | REG_IF_NACK
> +			| REG_IF_ARBLOST | REG_IF_BUSERR | REG_IF_RXDATAV);
> +
> +	/* to make bus idle */
> +	efm32_i2c_write32(ddata, REG_CMD, REG_CMD_ABORT);
> +
> +	ret = request_irq(ddata->irq, efm32_i2c_irq, 0, DRIVER_NAME, ddata);
> +	if (ret < 0) {
> +		dev_err(&pdev->dev, "failed to request irq (%d)\n", ret);
> +		return ret;
> +	}
> +
> +	ret = i2c_add_numbered_adapter(&ddata->adapter);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to add i2c adapter (%d)\n", ret);
> +		free_irq(ddata->irq, ddata);
> +
> +err_disable_clk:
> +		clk_disable_unprepare(ddata->clk);
> +	}
> +	return ret;
> +}
> +
> +static int efm32_i2c_remove(struct platform_device *pdev)
> +{
> +	struct efm32_i2c_ddata *ddata = platform_get_drvdata(pdev);
> +
> +	free_irq(ddata->irq, ddata);
> +	clk_disable_unprepare(ddata->clk);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id efm32_i2c_dt_ids[] = {
> +	{
> +		.compatible = "efm32,i2c",
> +	}, {
> +		/* sentinel */
> +	}
> +};
> +MODULE_DEVICE_TABLE(of, efm32_i2c_dt_ids);
> +
> +static struct platform_driver efm32_i2c_driver = {
> +	.probe = efm32_i2c_probe,
> +	.remove = efm32_i2c_remove,
> +
> +	.driver = {
> +		.name = DRIVER_NAME,
> +		.owner = THIS_MODULE,
> +		.of_match_table = efm32_i2c_dt_ids,
> +	},
> +};
> +module_platform_driver(efm32_i2c_driver);
> +
> +MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>");
> +MODULE_DESCRIPTION("EFM32 i2c driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:" DRIVER_NAME);
> diff --git a/include/linux/platform_data/efm32-i2c.h b/include/linux/platform_data/efm32-i2c.h
> new file mode 100644
> index 000000000000..5e175db68bb6
> --- /dev/null
> +++ b/include/linux/platform_data/efm32-i2c.h
> @@ -0,0 +1,15 @@
> +#ifndef __LINUX_PLATFORM_DATA_EFM32_I2C_H__
> +#define __LINUX_PLATFORM_DATA_EFM32_I2C_H__
> +
> +#include <linux/types.h>
> +
> +/**
> + * struct efm32_i2c_pdata
> + * @location: pinmux location for the I/O pins (to be written to the ROUTE
> + * 	register)
> + */
> +struct efm32_i2c_pdata {
> +	u8 location;
> +	unsigned long frequency; /* in Hz */
> +};
> +#endif /* ifndef __LINUX_PLATFORM_DATA_EFM32_I2C_H__ */
> -- 
> 1.8.5.2
> 
> 

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |