/****************************************************************************
* arch/arm/src/calypso/calypso_uwire.c
* Driver for Calypso uWire Master Controller
*
* (C) 2010 by Sylvain Munaut <tnt@246tNt.com>
*
* This source code is derivated from Osmocom-BB project and was
* relicensed as BSD with permission from original authors.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
**************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <stdint.h>
#include <stdio.h>
#include <debug.h>
#include "up_arch.h"
#define BASE_ADDR_UWIRE 0xfffe4000
#define UWIRE_REG(n) (BASE_ADDR_UWIRE+(n))
enum uwire_regs {
REG_DATA = 0x00,
REG_CSR = 0x02,
REG_SR1 = 0x04,
REG_SR2 = 0x06,
REG_SR3 = 0x08,
};
#define UWIRE_CSR_BITS_RD(n) (((n) & 0x1f) << 0)
#define UWIRE_CSR_BITS_WR(n) (((n) & 0x1f) << 5)
#define UWIRE_CSR_IDX(n) (((n) & 3) << 10)
#define UWIRE_CSR_CS_CMD (1 << 12)
#define UWIRE_CSR_START (1 << 13)
#define UWIRE_CSR_CSRB (1 << 14)
#define UWIRE_CSR_RDRB (1 << 15)
#define UWIRE_CSn_EDGE_RD (1 << 0) /* 1=falling 0=rising */
#define UWIRE_CSn_EDGE_WR (1 << 1) /* 1=falling 0=rising */
#define UWIRE_CSn_CS_LVL (1 << 2)
#define UWIRE_CSn_FRQ_DIV2 (0 << 3)
#define UWIRE_CSn_FRQ_DIV4 (1 << 3)
#define UWIRE_CSn_FRQ_DIV8 (2 << 3)
#define UWIRE_CSn_CKH
#define UWIRE_CSn_SHIFT(n) (((n) & 1) ? 6 : 0)
#define UWIRE_CSn_REG(n) (((n) & 2) ? REG_SR2 : REG_SR1)
#define UWIRE_SR3_CLK_EN (1 << 0)
#define UWIRE_SR3_CLK_DIV2 (0 << 1)
#define UWIRE_SR3_CLK_DIV4 (1 << 1)
#define UWIRE_SR3_CLK_DIV7 (2 << 1)
#define UWIRE_SR3_CLK_DIV10 (3 << 1)
static inline void _uwire_wait(int mask, int val)
{
while ((getreg16(UWIRE_REG(REG_CSR)) & mask) != val);
}
void uwire_init(void)
{
putreg16(UWIRE_SR3_CLK_EN | UWIRE_SR3_CLK_DIV2, UWIRE_REG(REG_SR3));
/* FIXME only init CS0 for now */
putreg16(((UWIRE_CSn_CS_LVL | UWIRE_CSn_FRQ_DIV2) << UWIRE_CSn_SHIFT(0)),
UWIRE_REG(UWIRE_CSn_REG(0)));
putreg16(UWIRE_CSR_IDX(0) | UWIRE_CSR_CS_CMD, UWIRE_REG(REG_CSR));
_uwire_wait(UWIRE_CSR_CSRB, 0);
}
int uwire_xfer(int cs, int bitlen, const void *dout, void *din)
{
uint16_t tmp = 0;
if (bitlen <= 0 || bitlen > 16)
return -1;
if (cs < 0 || cs > 4)
return -1;
/* FIXME uwire_init always selects CS0 for now */
dbg("uwire_xfer(dev_idx=%u, bitlen=%u\n", cs, bitlen);
/* select the chip */
putreg16(UWIRE_CSR_IDX(0) | UWIRE_CSR_CS_CMD, UWIRE_REG(REG_CSR));
_uwire_wait(UWIRE_CSR_CSRB, 0);
if (dout) {
if (bitlen <= 8)
tmp = *(uint8_t *)dout;
else if (bitlen <= 16)
tmp = *(uint16_t *)dout;
tmp <<= 16 - bitlen; /* align to MSB */
putreg16(tmp, UWIRE_REG(REG_DATA));
dbg(", data_out=0x%04hx", tmp);
}
tmp = (dout ? UWIRE_CSR_BITS_WR(bitlen) : 0) |
(din ? UWIRE_CSR_BITS_RD(bitlen) : 0) |
UWIRE_CSR_START;
putreg16(tmp, UWIRE_REG(REG_CSR));
_uwire_wait(UWIRE_CSR_CSRB, 0);
if (din) {
_uwire_wait(UWIRE_CSR_RDRB, UWIRE_CSR_RDRB);
tmp = getreg16(UWIRE_REG(REG_DATA));
dbg(", data_in=0x%08x", tmp);
if (bitlen <= 8)
*(uint8_t *)din = tmp & 0xff;
else if (bitlen <= 16)
*(uint16_t *)din = tmp & 0xffff;
}
/* unselect the chip */
putreg16(UWIRE_CSR_IDX(0) | 0, UWIRE_REG(REG_CSR));
_uwire_wait(UWIRE_CSR_CSRB, 0);
dbg(")\n");
return 0;
}
