diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-02-26 09:41:53 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-02-26 09:41:53 -0800 |
commit | 52caa59ed335616c5254adff7911465a57ed9f14 (patch) | |
tree | de0a1e91850c9e439e82f83f228d89fee3b90b09 | |
parent | 4c8c225abf972ce422c241579ce1d4d27eaeb166 (diff) | |
parent | 55827f4aa6442ddd1d6a4e1e32f2f457eb113c22 (diff) |
Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
"Highlights:
- new drivers for Intel ismt & Broadcom bcm2835
- a number of drivers got support for more variants and mostly got
cleaned up on the way (sis630, i801, at91, tegra, designware)
- i2c got rid of all *_set_drvdata(..., NULL) on remove/probe failure
- removed the i2c_smbus_process_call from the core since there are no
users
- mxs can now switch between PIO and DMA depending on the message
size and the bus speed can now be arbitrary
In addition, there is the usual bunch of fixes, cleanups, devm_*
conversions, etc"
Fixed conflict (and buggy devm_* conversion) in i2c-s3c2410.c
* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (39 commits)
i2c: Remove unneeded xxx_set_drvdata(..., NULL) calls
i2c: pxa: remove incorrect __exit annotations
i2c: ocores: Fix pointer to integer cast warning
i2c: tegra: remove warning dump if timeout happen in transfer
i2c: fix i2c-ismt.c printk format warning
i2c: i801: Add Device IDs for Intel Wellsburg PCH
i2c: add bcm2835 driver
i2c: ismt: Add Seth and Myself as maintainers
i2c: sis630: checkpatch cleanup
i2c: sis630: display unsigned hex
i2c: sis630: use hex to constants for SMBus commands
i2c: sis630: fix behavior after collision
i2c: sis630: clear sticky bits
i2c: sis630: Add SIS964 support
i2c: isch: Add module parameter for backbone clock rate if divider is unset
i2c: at91: fix unsed variable warning when building with !CONFIG_OF
i2c: Adding support for Intel iSMT SMBus 2.0 host controller
i2c: sh_mobile: don't send a stop condition by default inside transfers
i2c: sh_mobile: eliminate an open-coded "goto" loop
i2c: sh_mobile: fix timeout error handling
...
57 files changed, 2310 insertions, 514 deletions
diff --git a/Documentation/devicetree/bindings/i2c/brcm,bcm2835-i2c.txt b/Documentation/devicetree/bindings/i2c/brcm,bcm2835-i2c.txt new file mode 100644 index 00000000000..e9de3756752 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/brcm,bcm2835-i2c.txt @@ -0,0 +1,20 @@ +Broadcom BCM2835 I2C controller + +Required properties: +- compatible : Should be "brcm,bcm2835-i2c". +- reg: Should contain register location and length. +- interrupts: Should contain interrupt. +- clocks : The clock feeding the I2C controller. + +Recommended properties: +- clock-frequency : desired I2C bus clock frequency in Hz. + +Example: + +i2c@20205000 { + compatible = "brcm,bcm2835-i2c"; + reg = <0x7e205000 0x1000>; + interrupts = <2 21>; + clocks = <&clk_i2c>; + clock-frequency = <100000>; +}; diff --git a/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt b/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt index e9611ace879..f98d4c5b5cc 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt @@ -8,6 +8,8 @@ Required properties: (b) "samsung, s3c2440-i2c", for i2c compatible with s3c2440 i2c. (c) "samsung, s3c2440-hdmiphy-i2c", for s3c2440-like i2c used inside HDMIPHY block found on several samsung SoCs + (d) "samsung, exynos5440-i2c", for s3c2440-like i2c used + on EXYNOS5440 which does not need GPIO configuration. - reg: physical base address of the controller and length of memory mapped region. - interrupts: interrupt number to the cpu. diff --git a/Documentation/i2c/busses/i2c-i801 b/Documentation/i2c/busses/i2c-i801 index 157416e78cc..d55b8ab2d10 100644 --- a/Documentation/i2c/busses/i2c-i801 +++ b/Documentation/i2c/busses/i2c-i801 @@ -22,6 +22,8 @@ Supported adapters: * Intel Panther Point (PCH) * Intel Lynx Point (PCH) * Intel Lynx Point-LP (PCH) + * Intel Avoton (SOC) + * Intel Wellsburg (PCH) Datasheets: Publicly available at the Intel website On Intel Patsburg and later chipsets, both the normal host SMBus controller diff --git a/Documentation/i2c/busses/i2c-ismt b/Documentation/i2c/busses/i2c-ismt new file mode 100644 index 00000000000..737355822c0 --- /dev/null +++ b/Documentation/i2c/busses/i2c-ismt @@ -0,0 +1,36 @@ +Kernel driver i2c-ismt + +Supported adapters: + * Intel S12xx series SOCs + +Authors: + Bill Brown <bill.e.brown@intel.com> + + +Module Parameters +----------------- + +* bus_speed (unsigned int) +Allows changing of the bus speed. Normally, the bus speed is set by the BIOS +and never needs to be changed. However, some SMBus analyzers are too slow for +monitoring the bus during debug, thus the need for this module parameter. +Specify the bus speed in kHz. +Available bus frequency settings: + 0 no change + 80 kHz + 100 kHz + 400 kHz + 1000 kHz + + +Description +----------- + +The S12xx series of SOCs have a pair of integrated SMBus 2.0 controllers +targeted primarily at the microserver and storage markets. + +The S12xx series contain a pair of PCI functions. An output of lspci will show +something similar to the following: + + 00:13.0 System peripheral: Intel Corporation Centerton SMBus 2.0 Controller 0 + 00:13.1 System peripheral: Intel Corporation Centerton SMBus 2.0 Controller 1 diff --git a/Documentation/i2c/busses/i2c-sis630 b/Documentation/i2c/busses/i2c-sis630 index 0b969736693..ee794363107 100644 --- a/Documentation/i2c/busses/i2c-sis630 +++ b/Documentation/i2c/busses/i2c-sis630 @@ -4,9 +4,11 @@ Supported adapters: * Silicon Integrated Systems Corp (SiS) 630 chipset (Datasheet: available at http://www.sfr-fresh.com/linux) 730 chipset + 964 chipset * Possible other SiS chipsets ? Author: Alexander Malysh <amalysh@web.de> + Amaury Decrême <amaury.decreme@gmail.com> - SiS964 support Module Parameters ----------------- @@ -18,6 +20,7 @@ Module Parameters * high_clock = [1|0] Forcibly set Host Master Clock to 56KHz (default, what your BIOS use). DANGEROUS! This should be a bit faster, but freeze some systems (i.e. my Laptop). + SIS630/730 chip only. Description @@ -36,6 +39,12 @@ or like this: 00:00.0 Host bridge: Silicon Integrated Systems [SiS] 730 Host (rev 02) 00:01.0 ISA bridge: Silicon Integrated Systems [SiS] 85C503/5513 +or like this: + +00:00.0 Host bridge: Silicon Integrated Systems [SiS] 760/M760 Host (rev 02) +00:02.0 ISA bridge: Silicon Integrated Systems [SiS] SiS964 [MuTIOL Media IO] + LPC Controller (rev 36) + in your 'lspci' output , then this driver is for your chipset. Thank You diff --git a/Documentation/i2c/smbus-protocol b/Documentation/i2c/smbus-protocol index d1f22618e14..6012b12b351 100644 --- a/Documentation/i2c/smbus-protocol +++ b/Documentation/i2c/smbus-protocol @@ -137,8 +137,8 @@ available for writes where the two data bytes are the other way around (not SMBus compliant, but very popular.) -SMBus Process Call: i2c_smbus_process_call() -============================================= +SMBus Process Call: +=================== This command selects a device register (through the Comm byte), sends 16 bits of data to it, and reads 16 bits of data in return. diff --git a/Documentation/i2c/writing-clients b/Documentation/i2c/writing-clients index 3a94b0e6f60..6b344b516bf 100644 --- a/Documentation/i2c/writing-clients +++ b/Documentation/i2c/writing-clients @@ -365,8 +365,6 @@ in terms of it. Never use this function directly! s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command); s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value); - s32 i2c_smbus_process_call(struct i2c_client *client, - u8 command, u16 value); s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command, u8 *values); s32 i2c_smbus_write_block_data(struct i2c_client *client, @@ -381,6 +379,8 @@ These ones were removed from i2c-core because they had no users, but could be added back later if needed: s32 i2c_smbus_write_quick(struct i2c_client *client, u8 value); + s32 i2c_smbus_process_call(struct i2c_client *client, + u8 command, u16 value); s32 i2c_smbus_block_process_call(struct i2c_client *client, u8 command, u8 length, u8 *values); diff --git a/MAINTAINERS b/MAINTAINERS index ec9b7d2aa6a..1e5c3a4ece7 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3852,6 +3852,13 @@ F: drivers/i2c/busses/i2c-sis96x.c F: drivers/i2c/busses/i2c-via.c F: drivers/i2c/busses/i2c-viapro.c +I2C/SMBUS ISMT DRIVER +M: Seth Heasley <seth.heasley@intel.com> +M: Neil Horman <nhorman@tuxdriver.com> +L: linux-i2c@vger.kernel.org +F: drivers/i2c/busses/i2c-ismt.c +F: Documentation/i2c/busses/i2c-ismt + I2C/SMBUS STUB DRIVER M: "Mark M. Hoffman" <mhoffman@lightlink.com> L: linux-i2c@vger.kernel.org diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 8bb810e1900..a3725de9238 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -106,6 +106,8 @@ config I2C_I801 Panther Point (PCH) Lynx Point (PCH) Lynx Point-LP (PCH) + Avoton (SOC) + Wellsburg (PCH) This driver can also be built as a module. If so, the module will be called i2c-i801. @@ -121,6 +123,16 @@ config I2C_ISCH This driver can also be built as a module. If so, the module will be called i2c-isch. +config I2C_ISMT + tristate "Intel iSMT SMBus Controller" + depends on PCI && X86 + help + If you say yes to this option, support will be included for the Intel + iSMT SMBus host controller interface. + + This driver can also be built as a module. If so, the module will be + called i2c-ismt. + config I2C_PIIX4 tristate "Intel PIIX4 and compatible (ATI/AMD/Serverworks/Broadcom/SMSC)" depends on PCI @@ -186,11 +198,11 @@ config I2C_SIS5595 will be called i2c-sis5595. config I2C_SIS630 - tristate "SiS 630/730" + tristate "SiS 630/730/964" depends on PCI help If you say yes to this option, support will be included for the - SiS630 and SiS730 SMBus (a subset of I2C) interface. + SiS630, SiS730 and SiS964 SMBus (a subset of I2C) interface. This driver can also be built as a module. If so, the module will be called i2c-sis630. @@ -319,6 +331,18 @@ config I2C_AU1550 This driver can also be built as a module. If so, the module will be called i2c-au1550. +config I2C_BCM2835 + tristate "Broadcom BCM2835 I2C controller" + depends on ARCH_BCM2835 + help + If you say yes to this option, support will be included for the + BCM2835 I2C controller. + + If you don't know what to do here, say N. + + This support is also available as a module. If so, the module + will be called i2c-bcm2835. + config I2C_BLACKFIN_TWI tristate "Blackfin TWI I2C support" depends on BLACKFIN diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 6181f3ff263..8f4fc23b85b 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -14,6 +14,7 @@ obj-$(CONFIG_I2C_AMD756_S4882) += i2c-amd756-s4882.o obj-$(CONFIG_I2C_AMD8111) += i2c-amd8111.o obj-$(CONFIG_I2C_I801) += i2c-i801.o obj-$(CONFIG_I2C_ISCH) += i2c-isch.o +obj-$(CONFIG_I2C_ISMT) += i2c-ismt.o obj-$(CONFIG_I2C_NFORCE2) += i2c-nforce2.o obj-$(CONFIG_I2C_NFORCE2_S4985) += i2c-nforce2-s4985.o obj-$(CONFIG_I2C_PIIX4) += i2c-piix4.o @@ -30,6 +31,7 @@ obj-$(CONFIG_I2C_POWERMAC) += i2c-powermac.o # Embedded system I2C/SMBus host controller drivers obj-$(CONFIG_I2C_AT91) += i2c-at91.o obj-$(CONFIG_I2C_AU1550) += i2c-au1550.o +obj-$(CONFIG_I2C_BCM2835) += i2c-bcm2835.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 diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c index ebc22415469..75195e3f5dd 100644 --- a/drivers/i2c/busses/i2c-at91.c +++ b/drivers/i2c/busses/i2c-at91.c @@ -553,13 +553,6 @@ static struct at91_twi_pdata at91sam9g10_config = { .has_dma_support = false, }; -static struct at91_twi_pdata at91sam9x5_config = { - .clk_max_div = 7, - .clk_offset = 4, - .has_unre_flag = false, - .has_dma_support = true, -}; - static const struct platform_device_id at91_twi_devtypes[] = { { .name = "i2c-at91rm9200", @@ -582,8 +575,18 @@ static const struct platform_device_id at91_twi_devtypes[] = { }; #if defined(CONFIG_OF) +static struct at91_twi_pdata at91sam9x5_config = { + .clk_max_div = 7, + .clk_offset = 4, + .has_unre_flag = false, + .has_dma_support = true, +}; + static const struct of_device_id atmel_twi_dt_ids[] = { { + .compatible = "atmel,at91rm9200-i2c", + .data = &at91rm9200_config, + } , { .compatible = "atmel,at91sam9260-i2c", .data = &at91sam9260_config, } , { diff --git a/drivers/i2c/busses/i2c-au1550.c b/drivers/i2c/busses/i2c-au1550.c index b278298787d..b5b89239d62 100644 --- a/drivers/i2c/busses/i2c-au1550.c +++ b/drivers/i2c/busses/i2c-au1550.c @@ -376,7 +376,6 @@ static int i2c_au1550_remove(struct platform_device *pdev) { struct i2c_au1550_data *priv = platform_get_drvdata(pdev); - platform_set_drvdata(pdev, NULL); i2c_del_adapter(&priv->adap); i2c_au1550_disable(priv); iounmap(priv->psc_base); diff --git a/drivers/i2c/busses/i2c-bcm2835.c b/drivers/i2c/busses/i2c-bcm2835.c new file mode 100644 index 00000000000..ea4b08fc335 --- /dev/null +++ b/drivers/i2c/busses/i2c-bcm2835.c @@ -0,0 +1,342 @@ +/* + * BCM2835 master mode driver + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * 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/clk.h> +#include <linux/completion.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#define BCM2835_I2C_C 0x0 +#define BCM2835_I2C_S 0x4 +#define BCM2835_I2C_DLEN 0x8 +#define BCM2835_I2C_A 0xc +#define BCM2835_I2C_FIFO 0x10 +#define BCM2835_I2C_DIV 0x14 +#define BCM2835_I2C_DEL 0x18 +#define BCM2835_I2C_CLKT 0x1c + +#define BCM2835_I2C_C_READ BIT(0) +#define BCM2835_I2C_C_CLEAR BIT(4) /* bits 4 and 5 both clear */ +#define BCM2835_I2C_C_ST BIT(7) +#define BCM2835_I2C_C_INTD BIT(8) +#define BCM2835_I2C_C_INTT BIT(9) +#define BCM2835_I2C_C_INTR BIT(10) +#define BCM2835_I2C_C_I2CEN BIT(15) + +#define BCM2835_I2C_S_TA BIT(0) +#define BCM2835_I2C_S_DONE BIT(1) +#define BCM2835_I2C_S_TXW BIT(2) +#define BCM2835_I2C_S_RXR BIT(3) +#define BCM2835_I2C_S_TXD BIT(4) +#define BCM2835_I2C_S_RXD BIT(5) +#define BCM2835_I2C_S_TXE BIT(6) +#define BCM2835_I2C_S_RXF BIT(7) +#define BCM2835_I2C_S_ERR BIT(8) +#define BCM2835_I2C_S_CLKT BIT(9) +#define BCM2835_I2C_S_LEN BIT(10) /* Fake bit for SW error reporting */ + +#define BCM2835_I2C_TIMEOUT (msecs_to_jiffies(1000)) + +struct bcm2835_i2c_dev { + struct device *dev; + void __iomem *regs; + struct clk *clk; + int irq; + struct i2c_adapter adapter; + struct completion completion; + u32 msg_err; + u8 *msg_buf; + size_t msg_buf_remaining; +}; + +static inline void bcm2835_i2c_writel(struct bcm2835_i2c_dev *i2c_dev, + u32 reg, u32 val) +{ + writel(val, i2c_dev->regs + reg); +} + +static inline u32 bcm2835_i2c_readl(struct bcm2835_i2c_dev *i2c_dev, u32 reg) +{ + return readl(i2c_dev->regs + reg); +} + +static void bcm2835_fill_txfifo(struct bcm2835_i2c_dev *i2c_dev) +{ + u32 val; + + while (i2c_dev->msg_buf_remaining) { + val = bcm2835_i2c_readl(i2c_dev, BCM2835_I2C_S); + if (!(val & BCM2835_I2C_S_TXD)) + break; + bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_FIFO, + *i2c_dev->msg_buf); + i2c_dev->msg_buf++; + i2c_dev->msg_buf_remaining--; + } +} + +static void bcm2835_drain_rxfifo(struct bcm2835_i2c_dev *i2c_dev) +{ + u32 val; + + while (i2c_dev->msg_buf_remaining) { + val = bcm2835_i2c_readl(i2c_dev, BCM2835_I2C_S); + if (!(val & BCM2835_I2C_S_RXD)) + break; + *i2c_dev->msg_buf = bcm2835_i2c_readl(i2c_dev, + BCM2835_I2C_FIFO); + i2c_dev->msg_buf++; + i2c_dev->msg_buf_remaining--; + } +} + +static irqreturn_t bcm2835_i2c_isr(int this_irq, void *data) +{ + struct bcm2835_i2c_dev *i2c_dev = data; + u32 val, err; + + val = bcm2835_i2c_readl(i2c_dev, BCM2835_I2C_S); + bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_S, val); + + err = val & (BCM2835_I2C_S_CLKT | BCM2835_I2C_S_ERR); + if (err) { + i2c_dev->msg_err = err; + complete(&i2c_dev->completion); + return IRQ_HANDLED; + } + + if (val & BCM2835_I2C_S_RXD) { + bcm2835_drain_rxfifo(i2c_dev); + if (!(val & BCM2835_I2C_S_DONE)) + return IRQ_HANDLED; + } + + if (val & BCM2835_I2C_S_DONE) { + if (i2c_dev->msg_buf_remaining) + i2c_dev->msg_err = BCM2835_I2C_S_LEN; + else + i2c_dev->msg_err = 0; + complete(&i2c_dev->completion); + return IRQ_HANDLED; + } + + if (val & BCM2835_I2C_S_TXD) { + bcm2835_fill_txfifo(i2c_dev); + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + +static int bcm2835_i2c_xfer_msg(struct bcm2835_i2c_dev *i2c_dev, + struct i2c_msg *msg) +{ + u32 c; + int time_left; + + i2c_dev->msg_buf = msg->buf; + i2c_dev->msg_buf_remaining = msg->len; + INIT_COMPLETION(i2c_dev->completion); + + bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_C, BCM2835_I2C_C_CLEAR); + + if (msg->flags & I2C_M_RD) { + c = BCM2835_I2C_C_READ | BCM2835_I2C_C_INTR; + } else { + c = BCM2835_I2C_C_INTT; + bcm2835_fill_txfifo(i2c_dev); + } + c |= BCM2835_I2C_C_ST | BCM2835_I2C_C_INTD | BCM2835_I2C_C_I2CEN; + + bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_A, msg->addr); + bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_DLEN, msg->len); + bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_C, c); + + time_left = wait_for_completion_timeout(&i2c_dev->completion, + BCM2835_I2C_TIMEOUT); + bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_C, BCM2835_I2C_C_CLEAR); + if (!time_left) { + dev_err(i2c_dev->dev, "i2c transfer timed out\n"); + return -ETIMEDOUT; + } + + if (likely(!i2c_dev->msg_err)) + return 0; + + if ((i2c_dev->msg_err & BCM2835_I2C_S_ERR) && + (msg->flags & I2C_M_IGNORE_NAK)) + return 0; + + dev_err(i2c_dev->dev, "i2c transfer failed: %x\n", i2c_dev->msg_err); + + if (i2c_dev->msg_err & BCM2835_I2C_S_ERR) + return -EREMOTEIO; + else + return -EIO; +} + +static int bcm2835_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], + int num) +{ + struct bcm2835_i2c_dev *i2c_dev = i2c_get_adapdata(adap); + int i; + int ret = 0; + + for (i = 0; i < num; i++) { + ret = bcm2835_i2c_xfer_msg(i2c_dev, &msgs[i]); + if (ret) + break; + } + + return ret ?: i; +} + +static u32 bcm2835_i2c_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static const struct i2c_algorithm bcm2835_i2c_algo = { + .master_xfer = bcm2835_i2c_xfer, + .functionality = bcm2835_i2c_func, +}; + +static int bcm2835_i2c_probe(struct platform_device *pdev) +{ + struct bcm2835_i2c_dev *i2c_dev; + struct resource *mem, *requested, *irq; + u32 bus_clk_rate, divider; + int ret; + struct i2c_adapter *adap; + + i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL); + if (!i2c_dev) { + dev_err(&pdev->dev, "Cannot allocate i2c_dev\n"); + return -ENOMEM; + } + platform_set_drvdata(pdev, i2c_dev); + i2c_dev->dev = &pdev->dev; + init_completion(&i2c_dev->completion); + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!mem) { + dev_err(&pdev->dev, "No mem resource\n"); + return -ENODEV; + } + + requested = devm_request_mem_region(&pdev->dev, mem->start, + resource_size(mem), + dev_name(&pdev->dev)); + if (!requested) { + dev_err(&pdev->dev, "Could not claim register region\n"); + return -EBUSY; + } + + i2c_dev->regs = devm_ioremap(&pdev->dev, mem->start, + resource_size(mem)); + if (!i2c_dev->regs) { + dev_err(&pdev->dev, "Could not map registers\n"); + return -ENOMEM; + } + + i2c_dev->clk = de |