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Diffstat (limited to 'include/asm-v850/v850e_uarta.h')
| -rw-r--r-- | include/asm-v850/v850e_uarta.h | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/include/asm-v850/v850e_uarta.h b/include/asm-v850/v850e_uarta.h new file mode 100644 index 0000000..e483e09 --- /dev/null +++ b/include/asm-v850/v850e_uarta.h @@ -0,0 +1,278 @@ +/* + * 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__ */ |