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acrn-kernel/include/asm-v850/v850e_uarta.h

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/*
* include/asm-v850/v850e_uarta.h -- original V850E on-chip UART
*
* Copyright (C) 2001,02,03 NEC Electronics Corporation
* Copyright (C) 2001,02,03 Miles Bader <miles@gnu.org>
*
* This file is subject to the terms and conditions of the GNU General
* Public License. See the file COPYING in the main directory of this
* archive for more details.
*
* Written by Miles Bader <miles@gnu.org>
*/
/* This is the original V850E UART implementation is called just `UART' in
the docs, but we name this header file <asm/v850e_uarta.h> because the
name <asm/v850e_uart.h> is used for the common driver that handles both
`UART' and `UARTB' implementations. */
#ifndef __V850_V850E_UARTA_H__
#define __V850_V850E_UARTA_H__
/* Raw hardware interface. */
/* The base address of the UART control registers for channel N.
The default is the address used on the V850E/MA1. */
#ifndef V850E_UART_BASE_ADDR
#define V850E_UART_BASE_ADDR(n) (0xFFFFFA00 + 0x10 * (n))
#endif
/* Addresses of specific UART control registers for channel N.
The defaults are the addresses used on the V850E/MA1; if a platform
wants to redefine any of these, it must redefine them all. */
#ifndef V850E_UART_ASIM_ADDR
#define V850E_UART_ASIM_ADDR(n) (V850E_UART_BASE_ADDR(n) + 0x0)
#define V850E_UART_RXB_ADDR(n) (V850E_UART_BASE_ADDR(n) + 0x2)
#define V850E_UART_ASIS_ADDR(n) (V850E_UART_BASE_ADDR(n) + 0x3)
#define V850E_UART_TXB_ADDR(n) (V850E_UART_BASE_ADDR(n) + 0x4)
#define V850E_UART_ASIF_ADDR(n) (V850E_UART_BASE_ADDR(n) + 0x5)
#define V850E_UART_CKSR_ADDR(n) (V850E_UART_BASE_ADDR(n) + 0x6)
#define V850E_UART_BRGC_ADDR(n) (V850E_UART_BASE_ADDR(n) + 0x7)
#endif
/* UART config registers. */
#define V850E_UART_ASIM(n) (*(volatile u8 *)V850E_UART_ASIM_ADDR(n))
/* Control bits for config registers. */
#define V850E_UART_ASIM_CAE 0x80 /* clock enable */
#define V850E_UART_ASIM_TXE 0x40 /* transmit enable */
#define V850E_UART_ASIM_RXE 0x20 /* receive enable */
#define V850E_UART_ASIM_PS_MASK 0x18 /* mask covering parity-select bits */
#define V850E_UART_ASIM_PS_NONE 0x00 /* no parity */
#define V850E_UART_ASIM_PS_ZERO 0x08 /* zero parity */
#define V850E_UART_ASIM_PS_ODD 0x10 /* odd parity */
#define V850E_UART_ASIM_PS_EVEN 0x18 /* even parity */
#define V850E_UART_ASIM_CL_8 0x04 /* char len is 8 bits (otherwise, 7) */
#define V850E_UART_ASIM_SL_2 0x02 /* 2 stop bits (otherwise, 1) */
#define V850E_UART_ASIM_ISRM 0x01 /* generate INTSR interrupt on errors
(otherwise, generate INTSER) */
/* UART serial interface status registers. */
#define V850E_UART_ASIS(n) (*(volatile u8 *)V850E_UART_ASIS_ADDR(n))
/* Control bits for status registers. */
#define V850E_UART_ASIS_PE 0x04 /* parity error */
#define V850E_UART_ASIS_FE 0x02 /* framing error */
#define V850E_UART_ASIS_OVE 0x01 /* overrun error */
/* UART serial interface transmission status registers. */
#define V850E_UART_ASIF(n) (*(volatile u8 *)V850E_UART_ASIF_ADDR(n))
#define V850E_UART_ASIF_TXBF 0x02 /* transmit buffer flag (data in TXB) */
#define V850E_UART_ASIF_TXSF 0x01 /* transmit shift flag (sending data) */
/* UART receive buffer register. */
#define V850E_UART_RXB(n) (*(volatile u8 *)V850E_UART_RXB_ADDR(n))
/* UART transmit buffer register. */
#define V850E_UART_TXB(n) (*(volatile u8 *)V850E_UART_TXB_ADDR(n))
/* UART baud-rate generator control registers. */
#define V850E_UART_CKSR(n) (*(volatile u8 *)V850E_UART_CKSR_ADDR(n))
#define V850E_UART_CKSR_MAX 11
#define V850E_UART_BRGC(n) (*(volatile u8 *)V850E_UART_BRGC_ADDR(n))
#define V850E_UART_BRGC_MIN 8
#ifndef V850E_UART_CKSR_MAX_FREQ
#define V850E_UART_CKSR_MAX_FREQ (25*1000*1000)
#endif
/* Calculate the minimum value for CKSR on this processor. */
static inline unsigned v850e_uart_cksr_min (void)
{
int min = 0;
unsigned freq = V850E_UART_BASE_FREQ;
while (freq > V850E_UART_CKSR_MAX_FREQ) {
freq >>= 1;
min++;
}
return min;
}
/* Slightly abstract interface used by driver. */
/* Interrupts used by the UART. */
/* Received when the most recently transmitted character has been sent. */
#define V850E_UART_TX_IRQ(chan) IRQ_INTST (chan)
/* Received when a new character has been received. */
#define V850E_UART_RX_IRQ(chan) IRQ_INTSR (chan)
/* UART clock generator interface. */
/* This type encapsulates a particular uart frequency. */
typedef struct {
unsigned clk_divlog2;
unsigned brgen_count;
} v850e_uart_speed_t;
/* Calculate a uart speed from BAUD for this uart. */
static inline v850e_uart_speed_t v850e_uart_calc_speed (unsigned baud)
{
v850e_uart_speed_t speed;
/* Calculate the log2 clock divider and baud-rate counter values
(note that the UART divides the resulting clock by 2, so
multiply BAUD by 2 here to compensate). */
calc_counter_params (V850E_UART_BASE_FREQ, baud * 2,
v850e_uart_cksr_min(),
V850E_UART_CKSR_MAX, 8/*bits*/,
&speed.clk_divlog2, &speed.brgen_count);
return speed;
}
/* Return the current speed of uart channel CHAN. */
static inline v850e_uart_speed_t v850e_uart_speed (unsigned chan)
{
v850e_uart_speed_t speed;
speed.clk_divlog2 = V850E_UART_CKSR (chan);
speed.brgen_count = V850E_UART_BRGC (chan);
return speed;
}
/* Set the current speed of uart channel CHAN. */
static inline void v850e_uart_set_speed(unsigned chan,v850e_uart_speed_t speed)
{
V850E_UART_CKSR (chan) = speed.clk_divlog2;
V850E_UART_BRGC (chan) = speed.brgen_count;
}
static inline int
v850e_uart_speed_eq (v850e_uart_speed_t speed1, v850e_uart_speed_t speed2)
{
return speed1.clk_divlog2 == speed2.clk_divlog2
&& speed1.brgen_count == speed2.brgen_count;
}
/* Minimum baud rate possible. */
#define v850e_uart_min_baud() \
((V850E_UART_BASE_FREQ >> V850E_UART_CKSR_MAX) / (2 * 255) + 1)
/* Maximum baud rate possible. The error is quite high at max, though. */
#define v850e_uart_max_baud() \
((V850E_UART_BASE_FREQ >> v850e_uart_cksr_min()) / (2 *V850E_UART_BRGC_MIN))
/* The `maximum' clock rate the uart can used, which is wanted (though not
really used in any useful way) by the serial framework. */
#define v850e_uart_max_clock() \
((V850E_UART_BASE_FREQ >> v850e_uart_cksr_min()) / 2)
/* UART configuration interface. */
/* Type of the uart config register; must be a scalar. */
typedef u16 v850e_uart_config_t;
/* The uart hardware config register for channel CHAN. */
#define V850E_UART_CONFIG(chan) V850E_UART_ASIM (chan)
/* This config bit set if the uart is enabled. */
#define V850E_UART_CONFIG_ENABLED V850E_UART_ASIM_CAE
/* If the uart _isn't_ enabled, store this value to it to do so. */
#define V850E_UART_CONFIG_INIT V850E_UART_ASIM_CAE
/* Store this config value to disable the uart channel completely. */
#define V850E_UART_CONFIG_FINI 0
/* Setting/clearing these bits enable/disable TX/RX, respectively (but
otherwise generally leave things running). */
#define V850E_UART_CONFIG_RX_ENABLE V850E_UART_ASIM_RXE
#define V850E_UART_CONFIG_TX_ENABLE V850E_UART_ASIM_TXE
/* These masks define which config bits affect TX/RX modes, respectively. */
#define V850E_UART_CONFIG_RX_BITS \
(V850E_UART_ASIM_PS_MASK | V850E_UART_ASIM_CL_8 | V850E_UART_ASIM_ISRM)
#define V850E_UART_CONFIG_TX_BITS \
(V850E_UART_ASIM_PS_MASK | V850E_UART_ASIM_CL_8 | V850E_UART_ASIM_SL_2)
static inline v850e_uart_config_t v850e_uart_calc_config (unsigned cflags)
{
v850e_uart_config_t config = 0;
/* Figure out new configuration of control register. */
if (cflags & CSTOPB)
/* Number of stop bits, 1 or 2. */
config |= V850E_UART_ASIM_SL_2;
if ((cflags & CSIZE) == CS8)
/* Number of data bits, 7 or 8. */
config |= V850E_UART_ASIM_CL_8;
if (! (cflags & PARENB))
/* No parity check/generation. */
config |= V850E_UART_ASIM_PS_NONE;
else if (cflags & PARODD)
/* Odd parity check/generation. */
config |= V850E_UART_ASIM_PS_ODD;
else
/* Even parity check/generation. */
config |= V850E_UART_ASIM_PS_EVEN;
if (cflags & CREAD)
/* Reading enabled. */
config |= V850E_UART_ASIM_RXE;
config |= V850E_UART_ASIM_CAE;
config |= V850E_UART_ASIM_TXE; /* Writing is always enabled. */
config |= V850E_UART_ASIM_ISRM; /* Errors generate a read-irq. */
return config;
}
/* This should delay as long as necessary for a recently written config
setting to settle, before we turn the uart back on. */
static inline void
v850e_uart_config_delay (v850e_uart_config_t config, v850e_uart_speed_t speed)
{
/* The UART may not be reset properly unless we wait at least 2
`basic-clocks' until turning on the TXE/RXE bits again.
A `basic clock' is the clock used by the baud-rate generator,
i.e., the cpu clock divided by the 2^new_clk_divlog2.
The loop takes 2 insns, so loop CYCLES / 2 times. */
register unsigned count = 1 << speed.clk_divlog2;
while (--count != 0)
/* nothing */;
}
/* RX/TX interface. */
/* Return true if all characters awaiting transmission on uart channel N
have been transmitted. */
#define v850e_uart_xmit_done(n) \
(! (V850E_UART_ASIF(n) & V850E_UART_ASIF_TXBF))
/* Wait for this to be true. */
#define v850e_uart_wait_for_xmit_done(n) \
do { } while (! v850e_uart_xmit_done (n))
/* Return true if uart channel N is ready to transmit a character. */
#define v850e_uart_xmit_ok(n) \
(v850e_uart_xmit_done(n) && v850e_uart_cts(n))
/* Wait for this to be true. */
#define v850e_uart_wait_for_xmit_ok(n) \
do { } while (! v850e_uart_xmit_ok (n))
/* Write character CH to uart channel CHAN. */
#define v850e_uart_putc(chan, ch) (V850E_UART_TXB(chan) = (ch))
/* Return latest character read on channel CHAN. */
#define v850e_uart_getc(chan) V850E_UART_RXB (chan)
/* Return bit-mask of uart error status. */
#define v850e_uart_err(chan) V850E_UART_ASIS (chan)
/* Various error bits set in the error result. */
#define V850E_UART_ERR_OVERRUN V850E_UART_ASIS_OVE
#define V850E_UART_ERR_FRAME V850E_UART_ASIS_FE
#define V850E_UART_ERR_PARITY V850E_UART_ASIS_PE
#endif /* __V850_V850E_UARTA_H__ */
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