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	i2c: axxia: Add I2C driver for AXM55xx
Add I2C bus driver for the controller found in the LSI Axxia family SoCs. The driver implements 10-bit addressing and SMBus transfer modes via emulation (including SMBus block data read). Signed-off-by: Anders Berg <anders.berg@avagotech.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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								Documentation/devicetree/bindings/i2c/i2c-axxia.txt
									
									
									
									
									
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										30
									
								
								Documentation/devicetree/bindings/i2c/i2c-axxia.txt
									
									
									
									
									
										Normal file
									
								
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			@ -0,0 +1,30 @@
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LSI Axxia I2C
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Required properties :
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- compatible : Must be "lsi,api2c"
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- reg : Offset and length of the register set for the device
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- interrupts : the interrupt specifier
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- #address-cells : Must be <1>;
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- #size-cells : Must be <0>;
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- clock-names : Must contain "i2c".
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- clocks: Must contain an entry for each name in clock-names. See the common
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  clock bindings.
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Optional properties :
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- clock-frequency : Desired I2C bus clock frequency in Hz. If not specified,
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  the default 100 kHz frequency will be used. As only Normal and Fast modes
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  are supported, possible values are 100000 and 400000.
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Example :
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i2c@02010084000 {
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	compatible = "lsi,api2c";
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	device_type = "i2c";
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	#address-cells = <1>;
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	#size-cells = <0>;
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	reg = <0x20 0x10084000 0x00 0x1000>;
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	interrupts = <0 19 4>;
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	clocks = <&clk_per>;
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	clock-names = "i2c";
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	clock-frequency = <400000>;
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};
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			@ -337,6 +337,17 @@ config I2C_AU1550
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	  This driver can also be built as a module.  If so, the module
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	  will be called i2c-au1550.
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config I2C_AXXIA
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	tristate "Axxia I2C controller"
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	depends on ARCH_AXXIA || COMPILE_TEST
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	default ARCH_AXXIA
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	help
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	  Say yes if you want to support the I2C bus on Axxia platforms.
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	  Please note that this controller is limited to transfers of maximum
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	  255 bytes in length. Any attempt to to a larger transfer will return
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	  an error.
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config I2C_BCM2835
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	tristate "Broadcom BCM2835 I2C controller"
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	depends on ARCH_BCM2835
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			@ -31,6 +31,7 @@ obj-$(CONFIG_I2C_POWERMAC)	+= i2c-powermac.o
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# Embedded system I2C/SMBus host controller drivers
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obj-$(CONFIG_I2C_AT91)		+= i2c-at91.o
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obj-$(CONFIG_I2C_AU1550)	+= i2c-au1550.o
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obj-$(CONFIG_I2C_AXXIA)		+= i2c-axxia.o
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obj-$(CONFIG_I2C_BCM2835)	+= i2c-bcm2835.o
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obj-$(CONFIG_I2C_BLACKFIN_TWI)	+= i2c-bfin-twi.o
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obj-$(CONFIG_I2C_CADENCE)	+= i2c-cadence.o
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										559
									
								
								drivers/i2c/busses/i2c-axxia.c
									
									
									
									
									
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										559
									
								
								drivers/i2c/busses/i2c-axxia.c
									
									
									
									
									
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			@ -0,0 +1,559 @@
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/*
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 * This driver implements I2C master functionality using the LSI API2C
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 * controller.
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 *
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 * NOTE: The controller has a limitation in that it can only do transfers of
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 * maximum 255 bytes at a time. If a larger transfer is attempted, error code
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 * (-EINVAL) is returned.
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 *
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 * This software is licensed under the terms of the GNU General Public
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 * License version 2, as published by the Free Software Foundation, and
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 * may be copied, distributed, and modified under those terms.
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 */
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#include <linux/clk.h>
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#include <linux/clkdev.h>
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#include <linux/err.h>
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#include <linux/i2c.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/platform_device.h>
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#define SCL_WAIT_TIMEOUT_NS 25000000
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#define I2C_XFER_TIMEOUT    (msecs_to_jiffies(250))
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#define I2C_STOP_TIMEOUT    (msecs_to_jiffies(100))
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#define FIFO_SIZE           8
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#define GLOBAL_CONTROL		0x00
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#define   GLOBAL_MST_EN         BIT(0)
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#define   GLOBAL_SLV_EN         BIT(1)
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#define   GLOBAL_IBML_EN        BIT(2)
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#define INTERRUPT_STATUS	0x04
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#define INTERRUPT_ENABLE	0x08
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#define   INT_SLV               BIT(1)
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#define   INT_MST               BIT(0)
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#define WAIT_TIMER_CONTROL	0x0c
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#define   WT_EN			BIT(15)
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#define   WT_VALUE(_x)		((_x) & 0x7fff)
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#define IBML_TIMEOUT		0x10
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#define IBML_LOW_MEXT		0x14
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#define IBML_LOW_SEXT		0x18
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#define TIMER_CLOCK_DIV		0x1c
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#define I2C_BUS_MONITOR		0x20
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#define SOFT_RESET		0x24
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#define MST_COMMAND		0x28
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#define   CMD_BUSY		(1<<3)
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#define   CMD_MANUAL		(0x00 | CMD_BUSY)
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#define   CMD_AUTO		(0x01 | CMD_BUSY)
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#define MST_RX_XFER		0x2c
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#define MST_TX_XFER		0x30
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#define MST_ADDR_1		0x34
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#define MST_ADDR_2		0x38
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#define MST_DATA		0x3c
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#define MST_TX_FIFO		0x40
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#define MST_RX_FIFO		0x44
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#define MST_INT_ENABLE		0x48
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#define MST_INT_STATUS		0x4c
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#define   MST_STATUS_RFL	(1 << 13) /* RX FIFO serivce */
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#define   MST_STATUS_TFL	(1 << 12) /* TX FIFO service */
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#define   MST_STATUS_SNS	(1 << 11) /* Manual mode done */
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#define   MST_STATUS_SS		(1 << 10) /* Automatic mode done */
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#define   MST_STATUS_SCC	(1 << 9)  /* Stop complete */
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#define   MST_STATUS_IP		(1 << 8)  /* Invalid parameter */
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#define   MST_STATUS_TSS	(1 << 7)  /* Timeout */
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#define   MST_STATUS_AL		(1 << 6)  /* Arbitration lost */
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#define   MST_STATUS_ND		(1 << 5)  /* NAK on data phase */
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#define   MST_STATUS_NA		(1 << 4)  /* NAK on address phase */
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#define   MST_STATUS_NAK	(MST_STATUS_NA | \
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				 MST_STATUS_ND)
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#define   MST_STATUS_ERR	(MST_STATUS_NAK | \
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				 MST_STATUS_AL  | \
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				 MST_STATUS_IP  | \
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				 MST_STATUS_TSS)
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#define MST_TX_BYTES_XFRD	0x50
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#define MST_RX_BYTES_XFRD	0x54
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#define SCL_HIGH_PERIOD		0x80
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#define SCL_LOW_PERIOD		0x84
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#define SPIKE_FLTR_LEN		0x88
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#define SDA_SETUP_TIME		0x8c
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#define SDA_HOLD_TIME		0x90
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/**
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 * axxia_i2c_dev - I2C device context
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 * @base: pointer to register struct
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 * @msg: pointer to current message
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 * @msg_xfrd: number of bytes transferred in msg
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 * @msg_err: error code for completed message
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 * @msg_complete: xfer completion object
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 * @dev: device reference
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 * @adapter: core i2c abstraction
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 * @i2c_clk: clock reference for i2c input clock
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 * @bus_clk_rate: current i2c bus clock rate
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 */
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struct axxia_i2c_dev {
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	void __iomem *base;
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	struct i2c_msg *msg;
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	size_t msg_xfrd;
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	int msg_err;
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	struct completion msg_complete;
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	struct device *dev;
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	struct i2c_adapter adapter;
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	struct clk *i2c_clk;
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	u32 bus_clk_rate;
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};
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static void i2c_int_disable(struct axxia_i2c_dev *idev, u32 mask)
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{
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	u32 int_en;
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	int_en = readl(idev->base + MST_INT_ENABLE);
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	writel(int_en & ~mask, idev->base + MST_INT_ENABLE);
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}
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static void i2c_int_enable(struct axxia_i2c_dev *idev, u32 mask)
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{
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	u32 int_en;
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	int_en = readl(idev->base + MST_INT_ENABLE);
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	writel(int_en | mask, idev->base + MST_INT_ENABLE);
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}
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/**
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 * ns_to_clk - Convert time (ns) to clock cycles for the given clock frequency.
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 */
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static u32 ns_to_clk(u64 ns, u32 clk_mhz)
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{
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	return div_u64(ns * clk_mhz, 1000);
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}
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static int axxia_i2c_init(struct axxia_i2c_dev *idev)
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{
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	u32 divisor = clk_get_rate(idev->i2c_clk) / idev->bus_clk_rate;
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	u32 clk_mhz = clk_get_rate(idev->i2c_clk) / 1000000;
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	u32 t_setup;
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	u32 t_high, t_low;
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	u32 tmo_clk;
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	u32 prescale;
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	unsigned long timeout;
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	dev_dbg(idev->dev, "rate=%uHz per_clk=%uMHz -> ratio=1:%u\n",
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		idev->bus_clk_rate, clk_mhz, divisor);
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	/* Reset controller */
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	writel(0x01, idev->base + SOFT_RESET);
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	timeout = jiffies + msecs_to_jiffies(100);
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	while (readl(idev->base + SOFT_RESET) & 1) {
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		if (time_after(jiffies, timeout)) {
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			dev_warn(idev->dev, "Soft reset failed\n");
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			break;
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		}
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	}
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	/* Enable Master Mode */
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	writel(0x1, idev->base + GLOBAL_CONTROL);
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	if (idev->bus_clk_rate <= 100000) {
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		/* Standard mode SCL 50/50, tSU:DAT = 250 ns */
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		t_high = divisor * 1 / 2;
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		t_low = divisor * 1 / 2;
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		t_setup = ns_to_clk(250, clk_mhz);
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	} else {
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		/* Fast mode SCL 33/66, tSU:DAT = 100 ns */
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		t_high = divisor * 1 / 3;
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		t_low = divisor * 2 / 3;
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		t_setup = ns_to_clk(100, clk_mhz);
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	}
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	/* SCL High Time */
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	writel(t_high, idev->base + SCL_HIGH_PERIOD);
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	/* SCL Low Time */
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	writel(t_low, idev->base + SCL_LOW_PERIOD);
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	/* SDA Setup Time */
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	writel(t_setup, idev->base + SDA_SETUP_TIME);
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	/* SDA Hold Time, 300ns */
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	writel(ns_to_clk(300, clk_mhz), idev->base + SDA_HOLD_TIME);
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	/* Filter <50ns spikes */
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	writel(ns_to_clk(50, clk_mhz), idev->base + SPIKE_FLTR_LEN);
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	/* Configure Time-Out Registers */
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	tmo_clk = ns_to_clk(SCL_WAIT_TIMEOUT_NS, clk_mhz);
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	/* Find prescaler value that makes tmo_clk fit in 15-bits counter. */
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	for (prescale = 0; prescale < 15; ++prescale) {
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		if (tmo_clk <= 0x7fff)
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			break;
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		tmo_clk >>= 1;
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	}
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	if (tmo_clk > 0x7fff)
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		tmo_clk = 0x7fff;
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	/* Prescale divider (log2) */
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	writel(prescale, idev->base + TIMER_CLOCK_DIV);
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	/* Timeout in divided clocks */
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	writel(WT_EN | WT_VALUE(tmo_clk), idev->base + WAIT_TIMER_CONTROL);
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	/* Mask all master interrupt bits */
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	i2c_int_disable(idev, ~0);
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	/* Interrupt enable */
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	writel(0x01, idev->base + INTERRUPT_ENABLE);
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	return 0;
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}
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static int i2c_m_rd(const struct i2c_msg *msg)
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{
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	return (msg->flags & I2C_M_RD) != 0;
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}
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static int i2c_m_ten(const struct i2c_msg *msg)
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{
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	return (msg->flags & I2C_M_TEN) != 0;
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}
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static int i2c_m_recv_len(const struct i2c_msg *msg)
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{
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	return (msg->flags & I2C_M_RECV_LEN) != 0;
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}
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/**
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 * axxia_i2c_empty_rx_fifo - Fetch data from RX FIFO and update SMBus block
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 * transfer length if this is the first byte of such a transfer.
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 */
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static int axxia_i2c_empty_rx_fifo(struct axxia_i2c_dev *idev)
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{
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	struct i2c_msg *msg = idev->msg;
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	size_t rx_fifo_avail = readl(idev->base + MST_RX_FIFO);
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	int bytes_to_transfer = min(rx_fifo_avail, msg->len - idev->msg_xfrd);
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	while (bytes_to_transfer-- > 0) {
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		int c = readl(idev->base + MST_DATA);
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		if (idev->msg_xfrd == 0 && i2c_m_recv_len(msg)) {
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			/*
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			 * Check length byte for SMBus block read
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			 */
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			if (c <= 0 || c > I2C_SMBUS_BLOCK_MAX) {
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				idev->msg_err = -EPROTO;
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				i2c_int_disable(idev, ~0);
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				complete(&idev->msg_complete);
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				break;
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			}
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			msg->len = 1 + c;
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			writel(msg->len, idev->base + MST_RX_XFER);
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		}
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		msg->buf[idev->msg_xfrd++] = c;
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	}
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	return 0;
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}
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/**
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 * axxia_i2c_fill_tx_fifo - Fill TX FIFO from current message buffer.
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 * @return: Number of bytes left to transfer.
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 */
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static int axxia_i2c_fill_tx_fifo(struct axxia_i2c_dev *idev)
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{
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	struct i2c_msg *msg = idev->msg;
 | 
			
		||||
	size_t tx_fifo_avail = FIFO_SIZE - readl(idev->base + MST_TX_FIFO);
 | 
			
		||||
	int bytes_to_transfer = min(tx_fifo_avail, msg->len - idev->msg_xfrd);
 | 
			
		||||
	int ret = msg->len - idev->msg_xfrd - bytes_to_transfer;
 | 
			
		||||
 | 
			
		||||
	while (bytes_to_transfer-- > 0)
 | 
			
		||||
		writel(msg->buf[idev->msg_xfrd++], idev->base + MST_DATA);
 | 
			
		||||
 | 
			
		||||
	return ret;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static irqreturn_t axxia_i2c_isr(int irq, void *_dev)
 | 
			
		||||
{
 | 
			
		||||
	struct axxia_i2c_dev *idev = _dev;
 | 
			
		||||
	u32 status;
 | 
			
		||||
 | 
			
		||||
	if (!(readl(idev->base + INTERRUPT_STATUS) & INT_MST))
 | 
			
		||||
		return IRQ_NONE;
 | 
			
		||||
 | 
			
		||||
	/* Read interrupt status bits */
 | 
			
		||||
	status = readl(idev->base + MST_INT_STATUS);
 | 
			
		||||
 | 
			
		||||
	if (!idev->msg) {
 | 
			
		||||
		dev_warn(idev->dev, "unexpected interrupt\n");
 | 
			
		||||
		goto out;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	/* RX FIFO needs service? */
 | 
			
		||||
	if (i2c_m_rd(idev->msg) && (status & MST_STATUS_RFL))
 | 
			
		||||
		axxia_i2c_empty_rx_fifo(idev);
 | 
			
		||||
 | 
			
		||||
	/* TX FIFO needs service? */
 | 
			
		||||
	if (!i2c_m_rd(idev->msg) && (status & MST_STATUS_TFL)) {
 | 
			
		||||
		if (axxia_i2c_fill_tx_fifo(idev) == 0)
 | 
			
		||||
			i2c_int_disable(idev, MST_STATUS_TFL);
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	if (status & MST_STATUS_SCC) {
 | 
			
		||||
		/* Stop completed */
 | 
			
		||||
		i2c_int_disable(idev, ~0);
 | 
			
		||||
		complete(&idev->msg_complete);
 | 
			
		||||
	} else if (status & MST_STATUS_SNS) {
 | 
			
		||||
		/* Transfer done */
 | 
			
		||||
		i2c_int_disable(idev, ~0);
 | 
			
		||||
		if (i2c_m_rd(idev->msg) && idev->msg_xfrd < idev->msg->len)
 | 
			
		||||
			axxia_i2c_empty_rx_fifo(idev);
 | 
			
		||||
		complete(&idev->msg_complete);
 | 
			
		||||
	} else if (unlikely(status & MST_STATUS_ERR)) {
 | 
			
		||||
		/* Transfer error */
 | 
			
		||||
		i2c_int_disable(idev, ~0);
 | 
			
		||||
		if (status & MST_STATUS_AL)
 | 
			
		||||
			idev->msg_err = -EAGAIN;
 | 
			
		||||
		else if (status & MST_STATUS_NAK)
 | 
			
		||||
			idev->msg_err = -ENXIO;
 | 
			
		||||
		else
 | 
			
		||||
			idev->msg_err = -EIO;
 | 
			
		||||
		dev_dbg(idev->dev, "error %#x, addr=%#x rx=%u/%u tx=%u/%u\n",
 | 
			
		||||
			status,
 | 
			
		||||
			idev->msg->addr,
 | 
			
		||||
			readl(idev->base + MST_RX_BYTES_XFRD),
 | 
			
		||||
			readl(idev->base + MST_RX_XFER),
 | 
			
		||||
			readl(idev->base + MST_TX_BYTES_XFRD),
 | 
			
		||||
			readl(idev->base + MST_TX_XFER));
 | 
			
		||||
		complete(&idev->msg_complete);
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
out:
 | 
			
		||||
	/* Clear interrupt */
 | 
			
		||||
	writel(INT_MST, idev->base + INTERRUPT_STATUS);
 | 
			
		||||
 | 
			
		||||
	return IRQ_HANDLED;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static int axxia_i2c_xfer_msg(struct axxia_i2c_dev *idev, struct i2c_msg *msg)
 | 
			
		||||
{
 | 
			
		||||
	u32 int_mask = MST_STATUS_ERR | MST_STATUS_SNS;
 | 
			
		||||
	u32 rx_xfer, tx_xfer;
 | 
			
		||||
	u32 addr_1, addr_2;
 | 
			
		||||
	int ret;
 | 
			
		||||
 | 
			
		||||
	if (msg->len > 255) {
 | 
			
		||||
		dev_warn(idev->dev, "unsupported length %u\n", msg->len);
 | 
			
		||||
		return -EINVAL;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	idev->msg = msg;
 | 
			
		||||
	idev->msg_xfrd = 0;
 | 
			
		||||
	idev->msg_err = 0;
 | 
			
		||||
	reinit_completion(&idev->msg_complete);
 | 
			
		||||
 | 
			
		||||
	if (i2c_m_ten(msg)) {
 | 
			
		||||
		/* 10-bit address
 | 
			
		||||
		 *   addr_1: 5'b11110 | addr[9:8] | (R/nW)
 | 
			
		||||
		 *   addr_2: addr[7:0]
 | 
			
		||||
		 */
 | 
			
		||||
		addr_1 = 0xF0 | ((msg->addr >> 7) & 0x06);
 | 
			
		||||
		addr_2 = msg->addr & 0xFF;
 | 
			
		||||
	} else {
 | 
			
		||||
		/* 7-bit address
 | 
			
		||||
		 *   addr_1: addr[6:0] | (R/nW)
 | 
			
		||||
		 *   addr_2: dont care
 | 
			
		||||
		 */
 | 
			
		||||
		addr_1 = (msg->addr << 1) & 0xFF;
 | 
			
		||||
		addr_2 = 0;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	if (i2c_m_rd(msg)) {
 | 
			
		||||
		/* I2C read transfer */
 | 
			
		||||
		rx_xfer = i2c_m_recv_len(msg) ? I2C_SMBUS_BLOCK_MAX : msg->len;
 | 
			
		||||
		tx_xfer = 0;
 | 
			
		||||
		addr_1 |= 1;	/* Set the R/nW bit of the address */
 | 
			
		||||
	} else {
 | 
			
		||||
		/* I2C write transfer */
 | 
			
		||||
		rx_xfer = 0;
 | 
			
		||||
		tx_xfer = msg->len;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	writel(rx_xfer, idev->base + MST_RX_XFER);
 | 
			
		||||
	writel(tx_xfer, idev->base + MST_TX_XFER);
 | 
			
		||||
	writel(addr_1, idev->base + MST_ADDR_1);
 | 
			
		||||
	writel(addr_2, idev->base + MST_ADDR_2);
 | 
			
		||||
 | 
			
		||||
	if (i2c_m_rd(msg))
 | 
			
		||||
		int_mask |= MST_STATUS_RFL;
 | 
			
		||||
	else if (axxia_i2c_fill_tx_fifo(idev) != 0)
 | 
			
		||||
		int_mask |= MST_STATUS_TFL;
 | 
			
		||||
 | 
			
		||||
	/* Start manual mode */
 | 
			
		||||
	writel(CMD_MANUAL, idev->base + MST_COMMAND);
 | 
			
		||||
 | 
			
		||||
	i2c_int_enable(idev, int_mask);
 | 
			
		||||
 | 
			
		||||
	ret = wait_for_completion_timeout(&idev->msg_complete,
 | 
			
		||||
					  I2C_XFER_TIMEOUT);
 | 
			
		||||
 | 
			
		||||
	i2c_int_disable(idev, int_mask);
 | 
			
		||||
 | 
			
		||||
	if (readl(idev->base + MST_COMMAND) & CMD_BUSY)
 | 
			
		||||
		dev_warn(idev->dev, "busy after xfer\n");
 | 
			
		||||
 | 
			
		||||
	if (ret == 0)
 | 
			
		||||
		idev->msg_err = -ETIMEDOUT;
 | 
			
		||||
 | 
			
		||||
	if (unlikely(idev->msg_err) && idev->msg_err != -ENXIO)
 | 
			
		||||
		axxia_i2c_init(idev);
 | 
			
		||||
 | 
			
		||||
	return idev->msg_err;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static int axxia_i2c_stop(struct axxia_i2c_dev *idev)
 | 
			
		||||
{
 | 
			
		||||
	u32 int_mask = MST_STATUS_ERR | MST_STATUS_SCC;
 | 
			
		||||
	int ret;
 | 
			
		||||
 | 
			
		||||
	reinit_completion(&idev->msg_complete);
 | 
			
		||||
 | 
			
		||||
	/* Issue stop */
 | 
			
		||||
	writel(0xb, idev->base + MST_COMMAND);
 | 
			
		||||
	i2c_int_enable(idev, int_mask);
 | 
			
		||||
	ret = wait_for_completion_timeout(&idev->msg_complete,
 | 
			
		||||
					  I2C_STOP_TIMEOUT);
 | 
			
		||||
	i2c_int_disable(idev, int_mask);
 | 
			
		||||
	if (ret == 0)
 | 
			
		||||
		return -ETIMEDOUT;
 | 
			
		||||
 | 
			
		||||
	if (readl(idev->base + MST_COMMAND) & CMD_BUSY)
 | 
			
		||||
		dev_warn(idev->dev, "busy after stop\n");
 | 
			
		||||
 | 
			
		||||
	return 0;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static int
 | 
			
		||||
axxia_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 | 
			
		||||
{
 | 
			
		||||
	struct axxia_i2c_dev *idev = i2c_get_adapdata(adap);
 | 
			
		||||
	int i;
 | 
			
		||||
	int ret = 0;
 | 
			
		||||
 | 
			
		||||
	for (i = 0; ret == 0 && i < num; ++i)
 | 
			
		||||
		ret = axxia_i2c_xfer_msg(idev, &msgs[i]);
 | 
			
		||||
 | 
			
		||||
	axxia_i2c_stop(idev);
 | 
			
		||||
 | 
			
		||||
	return ret ? : i;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static u32 axxia_i2c_func(struct i2c_adapter *adap)
 | 
			
		||||
{
 | 
			
		||||
	u32 caps = (I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR |
 | 
			
		||||
		    I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA);
 | 
			
		||||
	return caps;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static const struct i2c_algorithm axxia_i2c_algo = {
 | 
			
		||||
	.master_xfer = axxia_i2c_xfer,
 | 
			
		||||
	.functionality = axxia_i2c_func,
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
static int axxia_i2c_probe(struct platform_device *pdev)
 | 
			
		||||
{
 | 
			
		||||
	struct device_node *np = pdev->dev.of_node;
 | 
			
		||||
	struct axxia_i2c_dev *idev = NULL;
 | 
			
		||||
	struct resource *res;
 | 
			
		||||
	void __iomem *base;
 | 
			
		||||
	int irq;
 | 
			
		||||
	int ret = 0;
 | 
			
		||||
 | 
			
		||||
	idev = devm_kzalloc(&pdev->dev, sizeof(*idev), GFP_KERNEL);
 | 
			
		||||
	if (!idev)
 | 
			
		||||
		return -ENOMEM;
 | 
			
		||||
 | 
			
		||||
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 | 
			
		||||
	base = devm_ioremap_resource(&pdev->dev, res);
 | 
			
		||||
	if (IS_ERR(base))
 | 
			
		||||
		return PTR_ERR(base);
 | 
			
		||||
 | 
			
		||||
	irq = platform_get_irq(pdev, 0);
 | 
			
		||||
	if (irq < 0) {
 | 
			
		||||
		dev_err(&pdev->dev, "missing interrupt resource\n");
 | 
			
		||||
		return irq;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	idev->i2c_clk = devm_clk_get(&pdev->dev, "i2c");
 | 
			
		||||
	if (IS_ERR(idev->i2c_clk)) {
 | 
			
		||||
		dev_err(&pdev->dev, "missing clock\n");
 | 
			
		||||
		return PTR_ERR(idev->i2c_clk);
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	idev->base = base;
 | 
			
		||||
	idev->dev = &pdev->dev;
 | 
			
		||||
	init_completion(&idev->msg_complete);
 | 
			
		||||
 | 
			
		||||
	of_property_read_u32(np, "clock-frequency", &idev->bus_clk_rate);
 | 
			
		||||
	if (idev->bus_clk_rate == 0)
 | 
			
		||||
		idev->bus_clk_rate = 100000;	/* default clock rate */
 | 
			
		||||
 | 
			
		||||
	ret = axxia_i2c_init(idev);
 | 
			
		||||
	if (ret) {
 | 
			
		||||
		dev_err(&pdev->dev, "failed to initialize\n");
 | 
			
		||||
		return ret;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	ret = devm_request_irq(&pdev->dev, irq, axxia_i2c_isr, 0,
 | 
			
		||||
			       pdev->name, idev);
 | 
			
		||||
	if (ret) {
 | 
			
		||||
		dev_err(&pdev->dev, "failed to claim IRQ%d\n", irq);
 | 
			
		||||
		return ret;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	clk_prepare_enable(idev->i2c_clk);
 | 
			
		||||
 | 
			
		||||
	i2c_set_adapdata(&idev->adapter, idev);
 | 
			
		||||
	strlcpy(idev->adapter.name, pdev->name, sizeof(idev->adapter.name));
 | 
			
		||||
	idev->adapter.owner = THIS_MODULE;
 | 
			
		||||
	idev->adapter.algo = &axxia_i2c_algo;
 | 
			
		||||
	idev->adapter.dev.parent = &pdev->dev;
 | 
			
		||||
	idev->adapter.dev.of_node = pdev->dev.of_node;
 | 
			
		||||
 | 
			
		||||
	platform_set_drvdata(pdev, idev);
 | 
			
		||||
 | 
			
		||||
	ret = i2c_add_adapter(&idev->adapter);
 | 
			
		||||
	if (ret) {
 | 
			
		||||
		dev_err(&pdev->dev, "failed to add adapter\n");
 | 
			
		||||
		return ret;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	return 0;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static int axxia_i2c_remove(struct platform_device *pdev)
 | 
			
		||||
{
 | 
			
		||||
	struct axxia_i2c_dev *idev = platform_get_drvdata(pdev);
 | 
			
		||||
 | 
			
		||||
	clk_disable_unprepare(idev->i2c_clk);
 | 
			
		||||
	i2c_del_adapter(&idev->adapter);
 | 
			
		||||
 | 
			
		||||
	return 0;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/* Match table for of_platform binding */
 | 
			
		||||
static const struct of_device_id axxia_i2c_of_match[] = {
 | 
			
		||||
	{ .compatible = "lsi,api2c", },
 | 
			
		||||
	{},
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
MODULE_DEVICE_TABLE(of, axxia_i2c_of_match);
 | 
			
		||||
 | 
			
		||||
static struct platform_driver axxia_i2c_driver = {
 | 
			
		||||
	.probe = axxia_i2c_probe,
 | 
			
		||||
	.remove = axxia_i2c_remove,
 | 
			
		||||
	.driver = {
 | 
			
		||||
		.name = "axxia-i2c",
 | 
			
		||||
		.of_match_table = axxia_i2c_of_match,
 | 
			
		||||
	},
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
module_platform_driver(axxia_i2c_driver);
 | 
			
		||||
 | 
			
		||||
MODULE_DESCRIPTION("Axxia I2C Bus driver");
 | 
			
		||||
MODULE_AUTHOR("Anders Berg <anders.berg@lsi.com>");
 | 
			
		||||
MODULE_LICENSE("GPL v2");
 | 
			
		||||
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		Reference in a new issue