cb06ff102e
In DMA support, The received data is not pushed to tty until the DMA buffer is filled. But some megabyte rate chips such as BT expect fast response and data should be pushed immediately. In order to fix this issue, We suggest the use of the timer for polling DMA buffer. In our test, no data loss occurred at high-baudrate as compared with interrupt- driven (We tested with 3Mbps). We changes: - We add timer for polling. If we set poll_timer to 10, every 10ms, timer handler checks the residue in the dma buffer and transfer data to the tty. Also, last_residue is updated for the next polling. - poll_timeout is used to prevent the timer's system cost. If poll_timeout is set to 3000 and no data is received in 3 seconds, we inactivate poll timer and driver falls back to interrupt-driven. When data is received again in FIFO and UART irq is occurred, we switch back to DMA mode and start polling. - We use consistent DMA mappings to avoid from the frequent cache operation of the timer function for default. - pl011_dma_rx_chars is modified. the pending size is recalculated because data can be taken by polling. - the polling time is adjusted if dma rx poll is enabled but no rate is specified. Ideal polling interval to push 1 character at every interval is the reciprocal of 'baud rate / 10 line bits per character / 1000 ms per sec'. But It is very aggressive to system. Experimentally, '10000000 / baud' is suitable to receive dozens of characters. the poll rate can be specified statically by dma_rx_poll_rate of the platform data as well. Changes compared to v1: - Use of consistent DMA mappings. - Added dma_rx_poll_rate in platform data to specify the polling interval. - Added dma_rx_poll_timeout in platform data to specify the polling timeout. Changes compared to v2: - Use of consistent DMA mappings for default. - Added dma_rx_poll_enable in platform data to adjust the polling time according to the baud rate. - remove unnecessary lock from the polling function. Signed-off-by: Chanho Min <chanho.min@lge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
215 lines
8.9 KiB
C
215 lines
8.9 KiB
C
/*
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* linux/include/asm-arm/hardware/serial_amba.h
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*
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* Internal header file for AMBA serial ports
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*
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* Copyright (C) ARM Limited
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* Copyright (C) 2000 Deep Blue Solutions Ltd.
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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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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#ifndef ASM_ARM_HARDWARE_SERIAL_AMBA_H
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#define ASM_ARM_HARDWARE_SERIAL_AMBA_H
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#include <linux/types.h>
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/* -------------------------------------------------------------------------------
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* From AMBA UART (PL010) Block Specification
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* -------------------------------------------------------------------------------
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* UART Register Offsets.
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*/
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#define UART01x_DR 0x00 /* Data read or written from the interface. */
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#define UART01x_RSR 0x04 /* Receive status register (Read). */
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#define UART01x_ECR 0x04 /* Error clear register (Write). */
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#define UART010_LCRH 0x08 /* Line control register, high byte. */
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#define ST_UART011_DMAWM 0x08 /* DMA watermark configure register. */
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#define UART010_LCRM 0x0C /* Line control register, middle byte. */
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#define ST_UART011_TIMEOUT 0x0C /* Timeout period register. */
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#define UART010_LCRL 0x10 /* Line control register, low byte. */
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#define UART010_CR 0x14 /* Control register. */
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#define UART01x_FR 0x18 /* Flag register (Read only). */
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#define UART010_IIR 0x1C /* Interrupt indentification register (Read). */
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#define UART010_ICR 0x1C /* Interrupt clear register (Write). */
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#define ST_UART011_LCRH_RX 0x1C /* Rx line control register. */
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#define UART01x_ILPR 0x20 /* IrDA low power counter register. */
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#define UART011_IBRD 0x24 /* Integer baud rate divisor register. */
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#define UART011_FBRD 0x28 /* Fractional baud rate divisor register. */
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#define UART011_LCRH 0x2c /* Line control register. */
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#define ST_UART011_LCRH_TX 0x2c /* Tx Line control register. */
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#define UART011_CR 0x30 /* Control register. */
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#define UART011_IFLS 0x34 /* Interrupt fifo level select. */
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#define UART011_IMSC 0x38 /* Interrupt mask. */
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#define UART011_RIS 0x3c /* Raw interrupt status. */
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#define UART011_MIS 0x40 /* Masked interrupt status. */
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#define UART011_ICR 0x44 /* Interrupt clear register. */
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#define UART011_DMACR 0x48 /* DMA control register. */
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#define ST_UART011_XFCR 0x50 /* XON/XOFF control register. */
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#define ST_UART011_XON1 0x54 /* XON1 register. */
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#define ST_UART011_XON2 0x58 /* XON2 register. */
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#define ST_UART011_XOFF1 0x5C /* XON1 register. */
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#define ST_UART011_XOFF2 0x60 /* XON2 register. */
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#define ST_UART011_ITCR 0x80 /* Integration test control register. */
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#define ST_UART011_ITIP 0x84 /* Integration test input register. */
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#define ST_UART011_ABCR 0x100 /* Autobaud control register. */
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#define ST_UART011_ABIMSC 0x15C /* Autobaud interrupt mask/clear register. */
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#define UART011_DR_OE (1 << 11)
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#define UART011_DR_BE (1 << 10)
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#define UART011_DR_PE (1 << 9)
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#define UART011_DR_FE (1 << 8)
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#define UART01x_RSR_OE 0x08
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#define UART01x_RSR_BE 0x04
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#define UART01x_RSR_PE 0x02
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#define UART01x_RSR_FE 0x01
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#define UART011_FR_RI 0x100
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#define UART011_FR_TXFE 0x080
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#define UART011_FR_RXFF 0x040
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#define UART01x_FR_TXFF 0x020
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#define UART01x_FR_RXFE 0x010
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#define UART01x_FR_BUSY 0x008
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#define UART01x_FR_DCD 0x004
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#define UART01x_FR_DSR 0x002
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#define UART01x_FR_CTS 0x001
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#define UART01x_FR_TMSK (UART01x_FR_TXFF + UART01x_FR_BUSY)
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#define UART011_CR_CTSEN 0x8000 /* CTS hardware flow control */
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#define UART011_CR_RTSEN 0x4000 /* RTS hardware flow control */
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#define UART011_CR_OUT2 0x2000 /* OUT2 */
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#define UART011_CR_OUT1 0x1000 /* OUT1 */
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#define UART011_CR_RTS 0x0800 /* RTS */
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#define UART011_CR_DTR 0x0400 /* DTR */
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#define UART011_CR_RXE 0x0200 /* receive enable */
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#define UART011_CR_TXE 0x0100 /* transmit enable */
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#define UART011_CR_LBE 0x0080 /* loopback enable */
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#define UART010_CR_RTIE 0x0040
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#define UART010_CR_TIE 0x0020
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#define UART010_CR_RIE 0x0010
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#define UART010_CR_MSIE 0x0008
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#define ST_UART011_CR_OVSFACT 0x0008 /* Oversampling factor */
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#define UART01x_CR_IIRLP 0x0004 /* SIR low power mode */
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#define UART01x_CR_SIREN 0x0002 /* SIR enable */
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#define UART01x_CR_UARTEN 0x0001 /* UART enable */
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#define UART011_LCRH_SPS 0x80
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#define UART01x_LCRH_WLEN_8 0x60
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#define UART01x_LCRH_WLEN_7 0x40
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#define UART01x_LCRH_WLEN_6 0x20
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#define UART01x_LCRH_WLEN_5 0x00
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#define UART01x_LCRH_FEN 0x10
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#define UART01x_LCRH_STP2 0x08
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#define UART01x_LCRH_EPS 0x04
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#define UART01x_LCRH_PEN 0x02
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#define UART01x_LCRH_BRK 0x01
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#define ST_UART011_DMAWM_RX_1 (0 << 3)
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#define ST_UART011_DMAWM_RX_2 (1 << 3)
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#define ST_UART011_DMAWM_RX_4 (2 << 3)
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#define ST_UART011_DMAWM_RX_8 (3 << 3)
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#define ST_UART011_DMAWM_RX_16 (4 << 3)
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#define ST_UART011_DMAWM_RX_32 (5 << 3)
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#define ST_UART011_DMAWM_RX_48 (6 << 3)
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#define ST_UART011_DMAWM_TX_1 0
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#define ST_UART011_DMAWM_TX_2 1
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#define ST_UART011_DMAWM_TX_4 2
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#define ST_UART011_DMAWM_TX_8 3
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#define ST_UART011_DMAWM_TX_16 4
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#define ST_UART011_DMAWM_TX_32 5
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#define ST_UART011_DMAWM_TX_48 6
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#define UART010_IIR_RTIS 0x08
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#define UART010_IIR_TIS 0x04
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#define UART010_IIR_RIS 0x02
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#define UART010_IIR_MIS 0x01
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#define UART011_IFLS_RX1_8 (0 << 3)
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#define UART011_IFLS_RX2_8 (1 << 3)
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#define UART011_IFLS_RX4_8 (2 << 3)
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#define UART011_IFLS_RX6_8 (3 << 3)
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#define UART011_IFLS_RX7_8 (4 << 3)
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#define UART011_IFLS_TX1_8 (0 << 0)
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#define UART011_IFLS_TX2_8 (1 << 0)
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#define UART011_IFLS_TX4_8 (2 << 0)
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#define UART011_IFLS_TX6_8 (3 << 0)
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#define UART011_IFLS_TX7_8 (4 << 0)
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/* special values for ST vendor with deeper fifo */
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#define UART011_IFLS_RX_HALF (5 << 3)
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#define UART011_IFLS_TX_HALF (5 << 0)
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#define UART011_OEIM (1 << 10) /* overrun error interrupt mask */
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#define UART011_BEIM (1 << 9) /* break error interrupt mask */
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#define UART011_PEIM (1 << 8) /* parity error interrupt mask */
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#define UART011_FEIM (1 << 7) /* framing error interrupt mask */
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#define UART011_RTIM (1 << 6) /* receive timeout interrupt mask */
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#define UART011_TXIM (1 << 5) /* transmit interrupt mask */
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#define UART011_RXIM (1 << 4) /* receive interrupt mask */
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#define UART011_DSRMIM (1 << 3) /* DSR interrupt mask */
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#define UART011_DCDMIM (1 << 2) /* DCD interrupt mask */
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#define UART011_CTSMIM (1 << 1) /* CTS interrupt mask */
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#define UART011_RIMIM (1 << 0) /* RI interrupt mask */
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#define UART011_OEIS (1 << 10) /* overrun error interrupt status */
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#define UART011_BEIS (1 << 9) /* break error interrupt status */
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#define UART011_PEIS (1 << 8) /* parity error interrupt status */
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#define UART011_FEIS (1 << 7) /* framing error interrupt status */
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#define UART011_RTIS (1 << 6) /* receive timeout interrupt status */
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#define UART011_TXIS (1 << 5) /* transmit interrupt status */
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#define UART011_RXIS (1 << 4) /* receive interrupt status */
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#define UART011_DSRMIS (1 << 3) /* DSR interrupt status */
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#define UART011_DCDMIS (1 << 2) /* DCD interrupt status */
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#define UART011_CTSMIS (1 << 1) /* CTS interrupt status */
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#define UART011_RIMIS (1 << 0) /* RI interrupt status */
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#define UART011_OEIC (1 << 10) /* overrun error interrupt clear */
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#define UART011_BEIC (1 << 9) /* break error interrupt clear */
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#define UART011_PEIC (1 << 8) /* parity error interrupt clear */
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#define UART011_FEIC (1 << 7) /* framing error interrupt clear */
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#define UART011_RTIC (1 << 6) /* receive timeout interrupt clear */
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#define UART011_TXIC (1 << 5) /* transmit interrupt clear */
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#define UART011_RXIC (1 << 4) /* receive interrupt clear */
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#define UART011_DSRMIC (1 << 3) /* DSR interrupt clear */
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#define UART011_DCDMIC (1 << 2) /* DCD interrupt clear */
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#define UART011_CTSMIC (1 << 1) /* CTS interrupt clear */
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#define UART011_RIMIC (1 << 0) /* RI interrupt clear */
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#define UART011_DMAONERR (1 << 2) /* disable dma on error */
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#define UART011_TXDMAE (1 << 1) /* enable transmit dma */
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#define UART011_RXDMAE (1 << 0) /* enable receive dma */
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#define UART01x_RSR_ANY (UART01x_RSR_OE|UART01x_RSR_BE|UART01x_RSR_PE|UART01x_RSR_FE)
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#define UART01x_FR_MODEM_ANY (UART01x_FR_DCD|UART01x_FR_DSR|UART01x_FR_CTS)
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#ifndef __ASSEMBLY__
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struct amba_device; /* in uncompress this is included but amba/bus.h is not */
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struct amba_pl010_data {
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void (*set_mctrl)(struct amba_device *dev, void __iomem *base, unsigned int mctrl);
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};
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struct dma_chan;
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struct amba_pl011_data {
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bool (*dma_filter)(struct dma_chan *chan, void *filter_param);
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void *dma_rx_param;
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void *dma_tx_param;
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bool dma_rx_poll_enable;
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unsigned int dma_rx_poll_rate;
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unsigned int dma_rx_poll_timeout;
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void (*init) (void);
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void (*exit) (void);
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};
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#endif
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#endif
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