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-rw-r--r--drivers/i2c/busses/i2c-at91.h191
1 files changed, 191 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-at91.h b/drivers/i2c/busses/i2c-at91.h
new file mode 100644
index 000000000..942e9c397
--- /dev/null
+++ b/drivers/i2c/busses/i2c-at91.h
@@ -0,0 +1,191 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * i2c Support for Atmel's AT91 Two-Wire Interface (TWI)
+ *
+ * Copyright (C) 2011 Weinmann Medical GmbH
+ * Author: Nikolaus Voss <n.voss@weinmann.de>
+ *
+ * Evolved from original work by:
+ * Copyright (C) 2004 Rick Bronson
+ * Converted to 2.6 by Andrew Victor <andrew@sanpeople.com>
+ *
+ * Borrowed heavily from original work by:
+ * Copyright (C) 2000 Philip Edelbrock <phil@stimpy.netroedge.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/i2c.h>
+#include <linux/platform_device.h>
+
+#define AT91_I2C_TIMEOUT msecs_to_jiffies(100) /* transfer timeout */
+#define AT91_I2C_DMA_THRESHOLD 8 /* enable DMA if transfer size is bigger than this threshold */
+#define AUTOSUSPEND_TIMEOUT 2000
+#define AT91_I2C_MAX_ALT_CMD_DATA_SIZE 256
+
+/* AT91 TWI register definitions */
+#define AT91_TWI_CR 0x0000 /* Control Register */
+#define AT91_TWI_START BIT(0) /* Send a Start Condition */
+#define AT91_TWI_STOP BIT(1) /* Send a Stop Condition */
+#define AT91_TWI_MSEN BIT(2) /* Master Transfer Enable */
+#define AT91_TWI_MSDIS BIT(3) /* Master Transfer Disable */
+#define AT91_TWI_SVEN BIT(4) /* Slave Transfer Enable */
+#define AT91_TWI_SVDIS BIT(5) /* Slave Transfer Disable */
+#define AT91_TWI_QUICK BIT(6) /* SMBus quick command */
+#define AT91_TWI_SWRST BIT(7) /* Software Reset */
+#define AT91_TWI_CLEAR BIT(15) /* Bus clear command */
+#define AT91_TWI_ACMEN BIT(16) /* Alternative Command Mode Enable */
+#define AT91_TWI_ACMDIS BIT(17) /* Alternative Command Mode Disable */
+#define AT91_TWI_THRCLR BIT(24) /* Transmit Holding Register Clear */
+#define AT91_TWI_RHRCLR BIT(25) /* Receive Holding Register Clear */
+#define AT91_TWI_LOCKCLR BIT(26) /* Lock Clear */
+#define AT91_TWI_FIFOEN BIT(28) /* FIFO Enable */
+#define AT91_TWI_FIFODIS BIT(29) /* FIFO Disable */
+
+#define AT91_TWI_MMR 0x0004 /* Master Mode Register */
+#define AT91_TWI_IADRSZ_1 0x0100 /* Internal Device Address Size */
+#define AT91_TWI_MREAD BIT(12) /* Master Read Direction */
+
+#define AT91_TWI_SMR 0x0008 /* Slave Mode Register */
+#define AT91_TWI_SMR_SADR_MAX 0x007f
+#define AT91_TWI_SMR_SADR(x) (((x) & AT91_TWI_SMR_SADR_MAX) << 16)
+
+#define AT91_TWI_IADR 0x000c /* Internal Address Register */
+
+#define AT91_TWI_CWGR 0x0010 /* Clock Waveform Generator Reg */
+#define AT91_TWI_CWGR_HOLD_MAX 0x1f
+#define AT91_TWI_CWGR_HOLD(x) (((x) & AT91_TWI_CWGR_HOLD_MAX) << 24)
+
+#define AT91_TWI_SR 0x0020 /* Status Register */
+#define AT91_TWI_TXCOMP BIT(0) /* Transmission Complete */
+#define AT91_TWI_RXRDY BIT(1) /* Receive Holding Register Ready */
+#define AT91_TWI_TXRDY BIT(2) /* Transmit Holding Register Ready */
+#define AT91_TWI_SVREAD BIT(3) /* Slave Read */
+#define AT91_TWI_SVACC BIT(4) /* Slave Access */
+#define AT91_TWI_OVRE BIT(6) /* Overrun Error */
+#define AT91_TWI_UNRE BIT(7) /* Underrun Error */
+#define AT91_TWI_NACK BIT(8) /* Not Acknowledged */
+#define AT91_TWI_EOSACC BIT(11) /* End Of Slave Access */
+#define AT91_TWI_LOCK BIT(23) /* TWI Lock due to Frame Errors */
+#define AT91_TWI_SCL BIT(24) /* TWI SCL status */
+#define AT91_TWI_SDA BIT(25) /* TWI SDA status */
+
+#define AT91_TWI_INT_MASK \
+ (AT91_TWI_TXCOMP | AT91_TWI_RXRDY | AT91_TWI_TXRDY | AT91_TWI_NACK \
+ | AT91_TWI_SVACC | AT91_TWI_EOSACC)
+
+#define AT91_TWI_IER 0x0024 /* Interrupt Enable Register */
+#define AT91_TWI_IDR 0x0028 /* Interrupt Disable Register */
+#define AT91_TWI_IMR 0x002c /* Interrupt Mask Register */
+#define AT91_TWI_RHR 0x0030 /* Receive Holding Register */
+#define AT91_TWI_THR 0x0034 /* Transmit Holding Register */
+
+#define AT91_TWI_ACR 0x0040 /* Alternative Command Register */
+#define AT91_TWI_ACR_DATAL_MASK GENMASK(15, 0)
+#define AT91_TWI_ACR_DATAL(len) ((len) & AT91_TWI_ACR_DATAL_MASK)
+#define AT91_TWI_ACR_DIR BIT(8)
+
+#define AT91_TWI_FILTR 0x0044
+#define AT91_TWI_FILTR_FILT BIT(0)
+#define AT91_TWI_FILTR_PADFEN BIT(1)
+#define AT91_TWI_FILTR_THRES(v) ((v) << 8)
+#define AT91_TWI_FILTR_THRES_MAX 7
+#define AT91_TWI_FILTR_THRES_MASK GENMASK(10, 8)
+
+#define AT91_TWI_FMR 0x0050 /* FIFO Mode Register */
+#define AT91_TWI_FMR_TXRDYM(mode) (((mode) & 0x3) << 0)
+#define AT91_TWI_FMR_TXRDYM_MASK (0x3 << 0)
+#define AT91_TWI_FMR_RXRDYM(mode) (((mode) & 0x3) << 4)
+#define AT91_TWI_FMR_RXRDYM_MASK (0x3 << 4)
+#define AT91_TWI_ONE_DATA 0x0
+#define AT91_TWI_TWO_DATA 0x1
+#define AT91_TWI_FOUR_DATA 0x2
+
+#define AT91_TWI_FLR 0x0054 /* FIFO Level Register */
+
+#define AT91_TWI_FSR 0x0060 /* FIFO Status Register */
+#define AT91_TWI_FIER 0x0064 /* FIFO Interrupt Enable Register */
+#define AT91_TWI_FIDR 0x0068 /* FIFO Interrupt Disable Register */
+#define AT91_TWI_FIMR 0x006c /* FIFO Interrupt Mask Register */
+
+#define AT91_TWI_VER 0x00fc /* Version Register */
+
+struct at91_twi_pdata {
+ unsigned clk_max_div;
+ unsigned clk_offset;
+ bool has_unre_flag;
+ bool has_alt_cmd;
+ bool has_hold_field;
+ bool has_dig_filtr;
+ bool has_adv_dig_filtr;
+ bool has_ana_filtr;
+ bool has_clear_cmd;
+};
+
+struct at91_twi_dma {
+ struct dma_chan *chan_rx;
+ struct dma_chan *chan_tx;
+ struct scatterlist sg[2];
+ struct dma_async_tx_descriptor *data_desc;
+ enum dma_data_direction direction;
+ bool buf_mapped;
+ bool xfer_in_progress;
+};
+
+struct at91_twi_dev {
+ struct device *dev;
+ void __iomem *base;
+ struct completion cmd_complete;
+ struct clk *clk;
+ u8 *buf;
+ size_t buf_len;
+ struct i2c_msg *msg;
+ int irq;
+ unsigned imr;
+ unsigned transfer_status;
+ struct i2c_adapter adapter;
+ unsigned twi_cwgr_reg;
+ struct at91_twi_pdata *pdata;
+ bool use_dma;
+ bool use_alt_cmd;
+ bool recv_len_abort;
+ u32 fifo_size;
+ struct at91_twi_dma dma;
+ bool slave_detected;
+ struct i2c_bus_recovery_info rinfo;
+#ifdef CONFIG_I2C_AT91_SLAVE_EXPERIMENTAL
+ unsigned smr;
+ struct i2c_client *slave;
+#endif
+ bool enable_dig_filt;
+ bool enable_ana_filt;
+ u32 filter_width;
+};
+
+unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg);
+void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val);
+void at91_disable_twi_interrupts(struct at91_twi_dev *dev);
+void at91_twi_irq_save(struct at91_twi_dev *dev);
+void at91_twi_irq_restore(struct at91_twi_dev *dev);
+void at91_init_twi_bus(struct at91_twi_dev *dev);
+
+void at91_init_twi_bus_master(struct at91_twi_dev *dev);
+int at91_twi_probe_master(struct platform_device *pdev, u32 phy_addr,
+ struct at91_twi_dev *dev);
+
+#ifdef CONFIG_I2C_AT91_SLAVE_EXPERIMENTAL
+void at91_init_twi_bus_slave(struct at91_twi_dev *dev);
+int at91_twi_probe_slave(struct platform_device *pdev, u32 phy_addr,
+ struct at91_twi_dev *dev);
+
+#else
+static inline void at91_init_twi_bus_slave(struct at91_twi_dev *dev) {}
+static inline int at91_twi_probe_slave(struct platform_device *pdev,
+ u32 phy_addr, struct at91_twi_dev *dev)
+{
+ return -EINVAL;
+}
+
+#endif