rockbox/firmware/target/arm/s5l8702/uc8702.h
Cástor Muñoz 9f27dc2103 iPod Classic: introduce s5l8702 UART driver
- polling/IRQ modes for Tx/Rx (TODO?: DMA)
- fine adjust for Tx/Rx bitrates
- auto bauding using HW circuitry
- status and stats in debug screen

Change-Id: I8650957063bc6d274d92eba2779d93ae73453fb6
2015-10-07 06:15:03 +02:00

321 lines
12 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2014 by Cástor Muñoz
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#ifndef __UC8702_H__
#define __UC8702_H__
#include <stdint.h>
#include <stdbool.h>
/* s5l8702 UART controller (UC8702):
*
* This UART is similar to the UART included in s5l8700 (see also
* s3c2416 and s3c6400 datasheets), UC8702 adds fine tunning for
* Tx/Rx bitrate and autobauding.
*/
/*#define UC8702_DEBUG*/
/*
* uc8702 HW definitions
*/
#define UART_PORT_MAX 4
#define UART_FIFO_SIZE 16
#define UART_PORT_BASE(b,i) ((b) + 0x4000 * (i))
/*
* controller registers
*/
#define REG32_PTR_T volatile uint32_t *
#define ULCON(ba) (*((REG32_PTR_T)((ba) + 0x00))) /* line control */
#define UCON(ba) (*((REG32_PTR_T)((ba) + 0x04))) /* control */
#define UFCON(ba) (*((REG32_PTR_T)((ba) + 0x08))) /* FIFO control */
#define UMCON(ba) (*((REG32_PTR_T)((ba) + 0x0C))) /* modem control */
#define UTRSTAT(ba) (*((REG32_PTR_T)((ba) + 0x10))) /* Tx/Rx status */
#define UERSTAT(ba) (*((REG32_PTR_T)((ba) + 0x14))) /* Rx error status */
#define UFSTAT(ba) (*((REG32_PTR_T)((ba) + 0x18))) /* FIFO status */
#define UMSTAT(ba) (*((REG32_PTR_T)((ba) + 0x1C))) /* modem status */
#define UTXH(ba) (*((REG32_PTR_T)((ba) + 0x20))) /* transmission hold */
#define URXH(ba) (*((REG32_PTR_T)((ba) + 0x24))) /* receive buffer */
#define UBRDIV(ba) (*((REG32_PTR_T)((ba) + 0x28))) /* baud rate divisor */
#define UABRCNT(ba) (*((REG32_PTR_T)((ba) + 0x2c))) /* autobaud counter */
#define UABRSTAT(ba) (*((REG32_PTR_T)((ba) + 0x30))) /* autobaud status */
#define UBRCONTX(ba) (*((REG32_PTR_T)((ba) + 0x34))) /* Tx frame config */
#define UBRCONRX(ba) (*((REG32_PTR_T)((ba) + 0x38))) /* Rx frame config */
/* ULCON register */
#define ULCON_DATA_BITS_MASK 0x3
#define ULCON_DATA_BITS_POS 0
#define ULCON_DATA_BITS_5 0
#define ULCON_DATA_BITS_6 1
#define ULCON_DATA_BITS_7 2
#define ULCON_DATA_BITS_8 3
#define ULCON_STOP_BITS_MASK 0x1
#define ULCON_STOP_BITS_POS 2
#define ULCON_STOP_BITS_1 0
#define ULCON_STOP_BITS_2 1
#define ULCON_PARITY_MASK 0x7
#define ULCON_PARITY_POS 3
#define ULCON_PARITY_NONE 0
#define ULCON_PARITY_ODD 4
#define ULCON_PARITY_EVEN 5
#define ULCON_PARITY_FORCE_1 6
#define ULCON_PARITY_FORCE_0 7
#define ULCON_INFRARED_EN_BIT (1 << 6)
/* UCON register */
#define UCON_RX_MODE_MASK 0x3
#define UCON_RX_MODE_POS 0
#define UCON_TX_MODE_MASK 0x3
#define UCON_TX_MODE_POS 2
#define UCON_MODE_DISABLED 0
#define UCON_MODE_INTREQ 1 /* INT request or polling mode */
#define UCON_MODE_UNDEFINED 2 /* Not defined, DMAREQ signal 1 ??? */
#define UCON_MODE_DMAREQ 3 /* DMA request (signal 0) */
#define UCON_SEND_BREAK_BIT (1 << 4)
#define UCON_LOOPBACK_BIT (1 << 5)
#define UCON_RX_TOUT_EN_BIT (1 << 7) /* Rx timeout enable */
#define UCON_CLKSEL_MASK 0x1
#define UCON_CLKSEL_POS 10
#define UCON_CLKSEL_PCLK 0 /* internal */
#define UCON_CLKSEL_ECLK 1 /* external */
#define UCON_RX_TOUT_INT_BIT (1 << 11) /* Rx timeout INT enable */
#define UCON_RX_INT_BIT (1 << 12) /* Rx INT enable */
#define UCON_TX_INT_BIT (1 << 13) /* Tx INT enable */
#define UCON_ERR_INT_BIT (1 << 14) /* Rx error INT enable */
#define UCON_MODEM_INT_BIT (1 << 15) /* modem INT enable (TBC) */
#define UCON_AUTOBR_INT_BIT (1 << 16) /* autobauding INT enable */
#define UCON_AUTOBR_START_BIT (1 << 17) /* autobauding start/stop */
/* UFCON register */
#define UFCON_FIFO_ENABLE_BIT (1 << 0)
#define UFCON_RX_FIFO_RST_BIT (1 << 1)
#define UFCON_TX_FIFO_RST_BIT (1 << 2)
#define UFCON_RX_FIFO_TRG_MASK 0x3
#define UFCON_RX_FIFO_TRG_POS 4
#define UFCON_RX_FIFO_TRG_4 0
#define UFCON_RX_FIFO_TRG_8 1
#define UFCON_RX_FIFO_TRG_12 2
#define UFCON_RX_FIFO_TRG_16 3
#define UFCON_TX_FIFO_TRG_MASK 0x3
#define UFCON_TX_FIFO_TRG_POS 6
#define UFCON_TX_FIFO_TRG_EMPTY 0
#define UFCON_TX_FIFO_TRG_4 1
#define UFCON_TX_FIFO_TRG_8 2
#define UFCON_TX_FIFO_TRG_12 3
/* UMCON register */
#define UMCON_RTS_BIT (1 << 0)
#define UMCON_AUTO_FLOW_CTRL_BIT (1 << 4)
/* UTRSTAT register */
#define UTRSTAT_RXBUF_RDY_BIT (1 << 0)
#define UTRSTAT_TXBUF_EMPTY_BIT (1 << 1)
#define UTRSTAT_TX_EMPTY_BIT (1 << 2)
#define UTRSTAT_RX_TOUT_INT_BIT (1 << 3) /* Rx timeout INT status */
#define UTRSTAT_RX_INT_BIT (1 << 4)
#define UTRSTAT_TX_INT_BIT (1 << 5)
#define UTRSTAT_ERR_INT_BIT (1 << 6)
#define UTRSTAT_MODEM_INT_BIT (1 << 7) /* modem INT status (TBC) */
#define UTRSTAT_AUTOBR_INT_BIT (1 << 8) /* autobauding INT status */
/* UERSTAT register */
#define UERSTAT_OVERRUN_BIT (1 << 0)
#define UERSTAT_PARITY_ERR_BIT (1 << 1)
#define UERSTAT_FRAME_ERR_BIT (1 << 2)
#define UERSTAT_BREAK_DETECT_BIT (1 << 3)
/* UFSTAT register */
#define UFSTAT_RX_FIFO_CNT_MASK 0xf
#define UFSTAT_RX_FIFO_CNT_POS 0
#define UFSTAT_TX_FIFO_CNT_MASK 0xf
#define UFSTAT_TX_FIFO_CNT_POS 4
#define UFSTAT_RX_FIFO_FULL_BIT (1 << 8)
#define UFSTAT_TX_FIFO_FULL_BIT (1 << 9)
#define UFSTAT_RX_FIFO_ERR_BIT (1 << 10) /* clears when reading UERSTAT
for the last pending error */
/* UMSTAT register */
#define UMSTAT_CTS_ACTIVE_BIT (1 << 0)
#define UMSTAT_CTS_DELTA_BIT (1 << 4)
/* Bitrate:
*
* Master UCLK clock is divided by 16 to serialize data, UBRDIV is
* used to configure nominal bit width, NBW = (UBRDIV+1)*16 in UCLK
* clock ticks.
*
* Fine tuning works shrining/expanding each individual bit of each
* frame. Each bit width can be incremented/decremented by 1/16 of
* nominal bit width, it seems UCLK is divided by 17 for expanded
* bits and divided by 15 for compressed bits. A whole frame of N
* bits can be shrined or expanded up to (NBW * N / 16) UCLK clock
* ticks (in 1/16 steps).
*/
/* UBRCONx register */
#define UC_FRAME_MAX_LEN 12 /* 1 start + 8 data + 1 par + 2 stop */
#define UBRCON_JITTER_MASK 0x3
#define UBRCON_JITTER_POS(bit) ((bit) << 1) /* 0..UC_FRAME_MAX_LEN-1 */
#define UBRCON_JITTER_NONE 0 /* no jitter for this bit */
#define UBRCON_JITTER_INC 1 /* increment 1/16 bit width */
#define UBRCON_JITTER_UNUSED 2 /* does nothing */
#define UBRCON_JITTER_DEC 3 /* decremet 1/16 bit width */
/* Autobauding:
*
* Initial UABRSTAT is NOT_INIT, it goes to READY when either of
* UCON_AUTOBR bits are enabled for the first time.
*
* Interrupts are enabled/disabled using UCON_AUTOBR_INT_BIT and
* checked using UTRSTAT_AUTOBR_INT_BIT, writing this bit cleans the
* interrupt.
*
* When UCON_AUTOBR_START_BIT is enabled, autobauding starts and the
* hardware waits for a low pulse on RX line.
*
* Once autobauding is started, when a falling edge is detected on
* the RX line, UABRSTAT changes to COUNTING status, an internal
* counter starts incrementing at UCLK clock frequency. During
* COUNTING state, UABRCNT reads as the value of the previous ABR
* count, not the value of the current internal count.
*
* Count finish when a rising edge is detected on the line, at this
* moment internal counter stops and it can be read using UABRCNT
* register, UABRSTAT goes to READY, AUTOBR_START_BIT is disabled,
* and an interrupt is raised if UCON_AUTOBR_INT_BIT is enabled.
*/
/* UABRSTAT register */
#define UABRSTAT_STATUS_MASK 0x3
#define UABRSTAT_STATUS_POS 0
#define UABRSTAT_STATUS_NOT_INIT 0 /* initial status */
#define UABRSTAT_STATUS_READY 1 /* machine is ready */
#define UABRSTAT_STATUS_COUNTING 2 /* count in progress */
/*
* structs
*/
struct uartc
{
/* static configuration */
const uint32_t baddr;
/* private */
struct uartc_port *port_l[UART_PORT_MAX];
};
struct uartc_port
{
/* static configuration */
struct uartc * const uartc;
const uint8_t id; /* port number */
const uint8_t rx_trg; /* UFCON_RX_FIFO_TRG_xxx */
const uint8_t tx_trg; /* UFCON_TX_FIFO_TRG_xxx */
const uint8_t clksel; /* UFCON_CLKSEL_xxx */
const uint32_t clkhz; /* UCLK (PCLK or ECLK) frequency */
void (* const tx_cb) (int len); /* ISRs */
void (* const rx_cb) (int len, char *data, char *err, uint32_t abr_cnt);
/* private */
uint32_t baddr;
uint32_t utrstat_int_mask;
bool abr_aborted;
uint8_t rx_data[UART_FIFO_SIZE]; /* data buffer for rx_cb */
uint8_t rx_err[UART_FIFO_SIZE]; /* error buffer for rx_cb */
#ifdef UC8702_DEBUG
uint32_t n_tx_bytes;
uint32_t n_rx_bytes;
uint32_t n_ovr_err;
uint32_t n_parity_err;
uint32_t n_frame_err;
uint32_t n_break_detect;
uint32_t n_abnormal0;
uint32_t n_abnormal1;
#endif
};
/*
* uc8702 low level API
*/
/* Initialization */
void uartc_open(struct uartc* uartc);
void uartc_close(struct uartc* uartc);
void uartc_port_open(struct uartc_port *port);
void uartc_port_close(struct uartc_port *port);
void uartc_port_rx_onoff(struct uartc_port *port, bool onoff);
void uartc_port_tx_onoff(struct uartc_port *port, bool onoff);
/* Configuration */
void uartc_port_config(struct uartc_port *port, unsigned int speed,
uint8_t data_bits, uint8_t parity, uint8_t stop_bits);
void uartc_port_set_bitrate(struct uartc_port *port, unsigned int speed);
void uartc_port_set_rx_mode(struct uartc_port *port, uint32_t mode);
void uartc_port_set_tx_mode(struct uartc_port *port, uint32_t mode);
/* Transmit */
bool uartc_port_tx_ready(struct uartc_port *port);
void uartc_port_tx_byte(struct uartc_port *port, uint8_t ch);
void uartc_port_send_byte(struct uartc_port *port, uint8_t ch);
/* Receive */
bool uartc_port_rx_ready(struct uartc_port *port);
uint8_t uartc_port_rx_byte(struct uartc_port *port);
uint8_t uartc_port_read_byte(struct uartc_port *port);
/* Autobauding */
void uartc_port_abr_start(struct uartc_port *port);
void uartc_port_abr_stop(struct uartc_port *port);
/* ISR */
void uartc_callback(struct uartc *uartc, int dev);
#ifdef UC8702_DEBUG
enum {
ABR_INFO_ST_IDLE,
ABR_INFO_ST_LAUNCHED,
ABR_INFO_ST_COUNTING,
ABR_INFO_ST_ABNORMAL
};
void uartc_port_get_line_info(struct uartc_port *port,
int *tx_status, int *rx_status,
int *tx_speed, int *rx_speed, char *line_cfg);
int uartc_port_get_abr_info(struct uartc_port *port, unsigned int *abr_cnt);
#endif
#endif /* __UC8702_H__ */