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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 00:20:36 +0200
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 00:20:36 +0200
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-v850/v850e_uarta.h
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz
linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'include/asm-v850/v850e_uarta.h')
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diff --git a/include/asm-v850/v850e_uarta.h b/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__ */