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Depending on the hardware, TX and RX FIFOs may be available. The RX FIFO can avoid receive overruns, especially when DMA transfers are not used to read data from the Receive Holding Register. For heavy system load, The CPU is likely not be able to fetch data fast enough from the RHR. In addition, the RX FIFO can supersede the DMA/PDC to control the RTS line when the Hardware Handshaking mode is enabled. Two thresholds are to be set for that purpose: - When the number of data in the RX FIFO crosses and becomes lower than or equal to the low threshold, the RTS line is set to low level: the remote peer is requested to send data. - When the number of data in the RX FIFO crosses and becomes greater than or equal to the high threshold, the RTS line is set to high level: the remote peer should stop sending new data. - low threshold <= high threshold Once these two thresholds are set properly, this new feature is enabled by setting the FIFO RTS Control bit of the FIFO Mode Register. FIFOs also introduce a new multiple data mode: the USART works either in multiple data mode or in single data (legacy) mode. If MODE9 bit is set into the Mode Register or if USMODE is set to either LIN_MASTER, LIN_SLAVE or LON_MODE, FIFOs operate in single data mode. Otherwise, they operate in multiple data mode. In this new multiple data mode, accesses to the Receive Holding Register or Transmit Holding Register slightly change. Since this driver implements neither the 9bit data feature (MODE9 bit set into the Mode Register) nor LIN modes, the USART works in multiple data mode whenever FIFOs are available and enabled. We also assume that data are 8bit wide. In single data mode, 32bit access CAN be used to read a single data from RHR or write a single data into THR. However in multiple data mode, a 32bit access to RHR now allows us to read four consecutive data from RX FIFO. Also a 32bit access to THR now allows to write four consecutive data into TX FIFO. So we MUST use 8bit access whenever only one data have to be read/written at a time. Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
166 lines
7.7 KiB
C
166 lines
7.7 KiB
C
/*
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* include/linux/atmel_serial.h
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*
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* Copyright (C) 2005 Ivan Kokshaysky
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* Copyright (C) SAN People
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*
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* USART registers.
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* Based on AT91RM9200 datasheet revision E.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#ifndef ATMEL_SERIAL_H
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#define ATMEL_SERIAL_H
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#define ATMEL_US_CR 0x00 /* Control Register */
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#define ATMEL_US_RSTRX BIT(2) /* Reset Receiver */
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#define ATMEL_US_RSTTX BIT(3) /* Reset Transmitter */
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#define ATMEL_US_RXEN BIT(4) /* Receiver Enable */
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#define ATMEL_US_RXDIS BIT(5) /* Receiver Disable */
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#define ATMEL_US_TXEN BIT(6) /* Transmitter Enable */
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#define ATMEL_US_TXDIS BIT(7) /* Transmitter Disable */
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#define ATMEL_US_RSTSTA BIT(8) /* Reset Status Bits */
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#define ATMEL_US_STTBRK BIT(9) /* Start Break */
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#define ATMEL_US_STPBRK BIT(10) /* Stop Break */
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#define ATMEL_US_STTTO BIT(11) /* Start Time-out */
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#define ATMEL_US_SENDA BIT(12) /* Send Address */
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#define ATMEL_US_RSTIT BIT(13) /* Reset Iterations */
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#define ATMEL_US_RSTNACK BIT(14) /* Reset Non Acknowledge */
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#define ATMEL_US_RETTO BIT(15) /* Rearm Time-out */
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#define ATMEL_US_DTREN BIT(16) /* Data Terminal Ready Enable */
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#define ATMEL_US_DTRDIS BIT(17) /* Data Terminal Ready Disable */
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#define ATMEL_US_RTSEN BIT(18) /* Request To Send Enable */
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#define ATMEL_US_RTSDIS BIT(19) /* Request To Send Disable */
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#define ATMEL_US_TXFCLR BIT(24) /* Transmit FIFO Clear */
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#define ATMEL_US_RXFCLR BIT(25) /* Receive FIFO Clear */
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#define ATMEL_US_TXFLCLR BIT(26) /* Transmit FIFO Lock Clear */
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#define ATMEL_US_FIFOEN BIT(30) /* FIFO enable */
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#define ATMEL_US_FIFODIS BIT(31) /* FIFO disable */
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#define ATMEL_US_MR 0x04 /* Mode Register */
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#define ATMEL_US_USMODE GENMASK(3, 0) /* Mode of the USART */
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#define ATMEL_US_USMODE_NORMAL 0
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#define ATMEL_US_USMODE_RS485 1
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#define ATMEL_US_USMODE_HWHS 2
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#define ATMEL_US_USMODE_MODEM 3
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#define ATMEL_US_USMODE_ISO7816_T0 4
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#define ATMEL_US_USMODE_ISO7816_T1 6
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#define ATMEL_US_USMODE_IRDA 8
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#define ATMEL_US_USCLKS GENMASK(5, 4) /* Clock Selection */
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#define ATMEL_US_USCLKS_MCK (0 << 4)
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#define ATMEL_US_USCLKS_MCK_DIV8 (1 << 4)
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#define ATMEL_US_USCLKS_SCK (3 << 4)
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#define ATMEL_US_CHRL GENMASK(7, 6) /* Character Length */
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#define ATMEL_US_CHRL_5 (0 << 6)
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#define ATMEL_US_CHRL_6 (1 << 6)
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#define ATMEL_US_CHRL_7 (2 << 6)
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#define ATMEL_US_CHRL_8 (3 << 6)
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#define ATMEL_US_SYNC BIT(8) /* Synchronous Mode Select */
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#define ATMEL_US_PAR GENMASK(11, 9) /* Parity Type */
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#define ATMEL_US_PAR_EVEN (0 << 9)
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#define ATMEL_US_PAR_ODD (1 << 9)
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#define ATMEL_US_PAR_SPACE (2 << 9)
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#define ATMEL_US_PAR_MARK (3 << 9)
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#define ATMEL_US_PAR_NONE (4 << 9)
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#define ATMEL_US_PAR_MULTI_DROP (6 << 9)
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#define ATMEL_US_NBSTOP GENMASK(13, 12) /* Number of Stop Bits */
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#define ATMEL_US_NBSTOP_1 (0 << 12)
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#define ATMEL_US_NBSTOP_1_5 (1 << 12)
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#define ATMEL_US_NBSTOP_2 (2 << 12)
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#define ATMEL_US_CHMODE GENMASK(15, 14) /* Channel Mode */
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#define ATMEL_US_CHMODE_NORMAL (0 << 14)
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#define ATMEL_US_CHMODE_ECHO (1 << 14)
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#define ATMEL_US_CHMODE_LOC_LOOP (2 << 14)
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#define ATMEL_US_CHMODE_REM_LOOP (3 << 14)
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#define ATMEL_US_MSBF BIT(16) /* Bit Order */
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#define ATMEL_US_MODE9 BIT(17) /* 9-bit Character Length */
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#define ATMEL_US_CLKO BIT(18) /* Clock Output Select */
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#define ATMEL_US_OVER BIT(19) /* Oversampling Mode */
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#define ATMEL_US_INACK BIT(20) /* Inhibit Non Acknowledge */
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#define ATMEL_US_DSNACK BIT(21) /* Disable Successive NACK */
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#define ATMEL_US_MAX_ITER GENMASK(26, 24) /* Max Iterations */
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#define ATMEL_US_FILTER BIT(28) /* Infrared Receive Line Filter */
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#define ATMEL_US_IER 0x08 /* Interrupt Enable Register */
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#define ATMEL_US_RXRDY BIT(0) /* Receiver Ready */
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#define ATMEL_US_TXRDY BIT(1) /* Transmitter Ready */
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#define ATMEL_US_RXBRK BIT(2) /* Break Received / End of Break */
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#define ATMEL_US_ENDRX BIT(3) /* End of Receiver Transfer */
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#define ATMEL_US_ENDTX BIT(4) /* End of Transmitter Transfer */
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#define ATMEL_US_OVRE BIT(5) /* Overrun Error */
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#define ATMEL_US_FRAME BIT(6) /* Framing Error */
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#define ATMEL_US_PARE BIT(7) /* Parity Error */
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#define ATMEL_US_TIMEOUT BIT(8) /* Receiver Time-out */
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#define ATMEL_US_TXEMPTY BIT(9) /* Transmitter Empty */
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#define ATMEL_US_ITERATION BIT(10) /* Max number of Repetitions Reached */
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#define ATMEL_US_TXBUFE BIT(11) /* Transmission Buffer Empty */
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#define ATMEL_US_RXBUFF BIT(12) /* Reception Buffer Full */
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#define ATMEL_US_NACK BIT(13) /* Non Acknowledge */
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#define ATMEL_US_RIIC BIT(16) /* Ring Indicator Input Change */
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#define ATMEL_US_DSRIC BIT(17) /* Data Set Ready Input Change */
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#define ATMEL_US_DCDIC BIT(18) /* Data Carrier Detect Input Change */
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#define ATMEL_US_CTSIC BIT(19) /* Clear to Send Input Change */
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#define ATMEL_US_RI BIT(20) /* RI */
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#define ATMEL_US_DSR BIT(21) /* DSR */
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#define ATMEL_US_DCD BIT(22) /* DCD */
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#define ATMEL_US_CTS BIT(23) /* CTS */
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#define ATMEL_US_IDR 0x0c /* Interrupt Disable Register */
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#define ATMEL_US_IMR 0x10 /* Interrupt Mask Register */
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#define ATMEL_US_CSR 0x14 /* Channel Status Register */
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#define ATMEL_US_RHR 0x18 /* Receiver Holding Register */
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#define ATMEL_US_THR 0x1c /* Transmitter Holding Register */
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#define ATMEL_US_SYNH BIT(15) /* Transmit/Receive Sync */
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#define ATMEL_US_BRGR 0x20 /* Baud Rate Generator Register */
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#define ATMEL_US_CD GENMASK(15, 0) /* Clock Divider */
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#define ATMEL_US_RTOR 0x24 /* Receiver Time-out Register */
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#define ATMEL_US_TO GENMASK(15, 0) /* Time-out Value */
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#define ATMEL_US_TTGR 0x28 /* Transmitter Timeguard Register */
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#define ATMEL_US_TG GENMASK(7, 0) /* Timeguard Value */
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#define ATMEL_US_FIDI 0x40 /* FI DI Ratio Register */
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#define ATMEL_US_NER 0x44 /* Number of Errors Register */
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#define ATMEL_US_IF 0x4c /* IrDA Filter Register */
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#define ATMEL_US_CMPR 0x90 /* Comparaison Register */
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#define ATMEL_US_FMR 0xa0 /* FIFO Mode Register */
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#define ATMEL_US_TXRDYM(data) (((data) & 0x3) << 0) /* TX Ready Mode */
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#define ATMEL_US_RXRDYM(data) (((data) & 0x3) << 4) /* RX Ready Mode */
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#define ATMEL_US_ONE_DATA 0x0
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#define ATMEL_US_TWO_DATA 0x1
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#define ATMEL_US_FOUR_DATA 0x2
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#define ATMEL_US_FRTSC BIT(7) /* FIFO RTS pin Control */
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#define ATMEL_US_TXFTHRES(thr) (((thr) & 0x3f) << 8) /* TX FIFO Threshold */
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#define ATMEL_US_RXFTHRES(thr) (((thr) & 0x3f) << 16) /* RX FIFO Threshold */
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#define ATMEL_US_RXFTHRES2(thr) (((thr) & 0x3f) << 24) /* RX FIFO Threshold2 */
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#define ATMEL_US_FLR 0xa4 /* FIFO Level Register */
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#define ATMEL_US_TXFL(reg) (((reg) >> 0) & 0x3f) /* TX FIFO Level */
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#define ATMEL_US_RXFL(reg) (((reg) >> 16) & 0x3f) /* RX FIFO Level */
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#define ATMEL_US_FIER 0xa8 /* FIFO Interrupt Enable Register */
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#define ATMEL_US_FIDR 0xac /* FIFO Interrupt Disable Register */
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#define ATMEL_US_FIMR 0xb0 /* FIFO Interrupt Mask Register */
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#define ATMEL_US_FESR 0xb4 /* FIFO Event Status Register */
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#define ATMEL_US_TXFEF BIT(0) /* Transmit FIFO Empty Flag */
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#define ATMEL_US_TXFFF BIT(1) /* Transmit FIFO Full Flag */
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#define ATMEL_US_TXFTHF BIT(2) /* Transmit FIFO Threshold Flag */
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#define ATMEL_US_RXFEF BIT(3) /* Receive FIFO Empty Flag */
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#define ATMEL_US_RXFFF BIT(4) /* Receive FIFO Full Flag */
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#define ATMEL_US_RXFTHF BIT(5) /* Receive FIFO Threshold Flag */
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#define ATMEL_US_TXFPTEF BIT(6) /* Transmit FIFO Pointer Error Flag */
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#define ATMEL_US_RXFPTEF BIT(7) /* Receive FIFO Pointer Error Flag */
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#define ATMEL_US_TXFLOCK BIT(8) /* Transmit FIFO Lock (FESR only) */
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#define ATMEL_US_RXFTHF2 BIT(9) /* Receive FIFO Threshold Flag 2 */
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#define ATMEL_US_NAME 0xf0 /* Ip Name */
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#define ATMEL_US_VERSION 0xfc /* Ip Version */
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#endif
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