i2c: designware: introducing I2C_SLAVE definitions

- Definitions were added to core library
- A example was added to designware-core.txt Documentation that shows
  how the slave can be setup using DTS

SLAVE related definitions were added to the core of the controller.

Signed-off-by: Luis Oliveira <lolivei@synopsys.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Documentation/devicetree/bindings/i2c/i2c-designware.txt

@@ -20,7 +20,7 @@ Optional properties :
  - i2c-sda-falling-time-ns : should contain the SDA falling time in nanoseconds.
    This value which is by default 300ns is used to compute the tHIGH period.
 
-Example :
+Examples :
 
 	i2c@f0000 {
 		#address-cells = <1>;
@@ -43,3 +43,17 @@ Example :
 		i2c-sda-falling-time-ns = <300>;
 		i2c-scl-falling-time-ns = <300>;
 	};
+
+	i2c@1120000 {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <0x2000 0x100>;
+		clock-frequency = <400000>;
+		clocks = <&i2cclk>;
+		interrupts = <0>;
+
+		eeprom@64 {
+			compatible = "linux,slave-24c02";
+			reg = <0x40000064>;
+		};
+	};

drivers/i2c/busses/i2c-designware-core.h

@@ -1,5 +1,5 @@
 /*
- * Synopsys DesignWare I2C adapter driver (master only).
+ * Synopsys DesignWare I2C adapter driver.
  *
  * Based on the TI DAVINCI I2C adapter driver.
  *
@@ -37,15 +37,20 @@
 #define DW_IC_CON_SPEED_FAST		0x4
 #define DW_IC_CON_SPEED_HIGH		0x6
 #define DW_IC_CON_SPEED_MASK		0x6
+#define DW_IC_CON_10BITADDR_SLAVE		0x8
 #define DW_IC_CON_10BITADDR_MASTER	0x10
 #define DW_IC_CON_RESTART_EN		0x20
 #define DW_IC_CON_SLAVE_DISABLE		0x40
+#define DW_IC_CON_STOP_DET_IFADDRESSED		0x80
+#define DW_IC_CON_TX_EMPTY_CTRL		0x100
+#define DW_IC_CON_RX_FIFO_FULL_HLD_CTRL		0x200
 
 /*
  * Registers offset
  */
 #define DW_IC_CON		0x0
 #define DW_IC_TAR		0x4
+#define DW_IC_SAR		0x8
 #define DW_IC_DATA_CMD		0x10
 #define DW_IC_SS_SCL_HCNT	0x14
 #define DW_IC_SS_SCL_LCNT	0x18
@@ -76,6 +81,7 @@
 #define DW_IC_SDA_HOLD		0x7c
 #define DW_IC_TX_ABRT_SOURCE	0x80
 #define DW_IC_ENABLE_STATUS	0x9c
+#define DW_IC_CLR_RESTART_DET	0xa8
 #define DW_IC_COMP_PARAM_1	0xf4
 #define DW_IC_COMP_VERSION	0xf8
 #define DW_IC_SDA_HOLD_MIN_VERS	0x3131312A
@@ -94,15 +100,22 @@
 #define DW_IC_INTR_STOP_DET	0x200
 #define DW_IC_INTR_START_DET	0x400
 #define DW_IC_INTR_GEN_CALL	0x800
+#define DW_IC_INTR_RESTART_DET	0x1000
 
 #define DW_IC_INTR_DEFAULT_MASK		(DW_IC_INTR_RX_FULL | \
 					 DW_IC_INTR_TX_ABRT | \
 					 DW_IC_INTR_STOP_DET)
 #define DW_IC_INTR_MASTER_MASK		(DW_IC_INTR_DEFAULT_MASK | \
 					 DW_IC_INTR_TX_EMPTY)
+#define DW_IC_INTR_SLAVE_MASK		(DW_IC_INTR_DEFAULT_MASK | \
+					 DW_IC_INTR_RX_DONE | \
+					 DW_IC_INTR_RX_UNDER | \
+					 DW_IC_INTR_RD_REQ)
+
 #define DW_IC_STATUS_ACTIVITY		0x1
 #define DW_IC_STATUS_TFE		BIT(2)
 #define DW_IC_STATUS_MASTER_ACTIVITY	BIT(5)
+#define DW_IC_STATUS_SLAVE_ACTIVITY	BIT(6)
 
 #define DW_IC_SDA_HOLD_RX_SHIFT		16
 #define DW_IC_SDA_HOLD_RX_MASK		GENMASK(23, DW_IC_SDA_HOLD_RX_SHIFT)
@@ -115,7 +128,7 @@
 #define DW_IC_COMP_PARAM_1_SPEED_MODE_MASK	GENMASK(3, 2)
 
 /*
- * Status codes
+ * status codes
  */
 #define STATUS_IDLE			0x0
 #define STATUS_WRITE_IN_PROGRESS	0x1
@@ -123,6 +136,12 @@
 
 #define TIMEOUT			20 /* ms */
 
+/*
+ * operation modes
+ */
+#define DW_IC_MASTER		0
+#define DW_IC_SLAVE		1
+
 /*
  * Hardware abort codes from the DW_IC_TX_ABRT_SOURCE register
  *
@@ -140,6 +159,9 @@
 #define ABRT_10B_RD_NORSTRT	10
 #define ABRT_MASTER_DIS		11
 #define ARB_LOST		12
+#define ABRT_SLAVE_FLUSH_TXFIFO	13
+#define ABRT_SLAVE_ARBLOST	14
+#define ABRT_SLAVE_RD_INTX	15
 
 #define DW_IC_TX_ABRT_7B_ADDR_NOACK	(1UL << ABRT_7B_ADDR_NOACK)
 #define DW_IC_TX_ABRT_10ADDR1_NOACK	(1UL << ABRT_10ADDR1_NOACK)
@@ -152,6 +174,9 @@
 #define DW_IC_TX_ABRT_10B_RD_NORSTRT	(1UL << ABRT_10B_RD_NORSTRT)
 #define DW_IC_TX_ABRT_MASTER_DIS	(1UL << ABRT_MASTER_DIS)
 #define DW_IC_TX_ARB_LOST		(1UL << ARB_LOST)
+#define DW_IC_RX_ABRT_SLAVE_RD_INTX	(1UL << ABRT_SLAVE_RD_INTX)
+#define DW_IC_RX_ABRT_SLAVE_ARBLOST	(1UL << ABRT_SLAVE_ARBLOST)
+#define DW_IC_RX_ABRT_SLAVE_FLUSH_TXFIFO	(1UL << ABRT_SLAVE_FLUSH_TXFIFO)
 
 #define DW_IC_TX_ABRT_NOACK		(DW_IC_TX_ABRT_7B_ADDR_NOACK | \
 					 DW_IC_TX_ABRT_10ADDR1_NOACK | \
@@ -166,6 +191,7 @@
  * @base: IO registers pointer
  * @cmd_complete: tx completion indicator
  * @clk: input reference clock
+ * @slave: represent an I2C slave device
  * @cmd_err: run time hadware error code
  * @msgs: points to an array of messages currently being transferred
  * @msgs_num: the number of elements in msgs
@@ -182,6 +208,7 @@
  * @abort_source: copy of the TX_ABRT_SOURCE register
  * @irq: interrupt number for the i2c master
  * @adapter: i2c subsystem adapter node
+ * @slave_cfg: configuration for the slave device
  * @tx_fifo_depth: depth of the hardware tx fifo
  * @rx_fifo_depth: depth of the hardware rx fifo
  * @rx_outstanding: current master-rx elements in tx fifo
@@ -212,6 +239,7 @@ struct dw_i2c_dev {
 	struct completion	cmd_complete;
 	struct clk		*clk;
 	struct reset_control	*rst;
+	struct i2c_client		*slave;
 	u32			(*get_clk_rate_khz) (struct dw_i2c_dev *dev);
 	struct dw_pci_controller *controller;
 	int			cmd_err;
@@ -231,6 +259,7 @@ struct dw_i2c_dev {
 	struct i2c_adapter	adapter;
 	u32			functionality;
 	u32			master_cfg;
+	u32			slave_cfg;
 	unsigned int		tx_fifo_depth;
 	unsigned int		rx_fifo_depth;
 	int			rx_outstanding;