spi: add new driver for OpenCores tiny_spi
This patch adds support for OpenCores tiny_spi. http://opencores.org/project,tiny_spi Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
This commit is contained in:
Thomas Chou
Wolfgang Denk
parent
e89516f031
commit
dea6386b71
@ -35,6 +35,7 @@ COBJS-$(CONFIG_KIRKWOOD_SPI) += kirkwood_spi.o
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COBJS-$(CONFIG_MPC52XX_SPI) += mpc52xx_spi.o
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COBJS-$(CONFIG_MPC8XXX_SPI) += mpc8xxx_spi.o
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COBJS-$(CONFIG_MXC_SPI) += mxc_spi.o
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COBJS-$(CONFIG_OC_TINY_SPI) += oc_tiny_spi.o
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COBJS-$(CONFIG_OMAP3_SPI) += omap3_spi.o
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COBJS-$(CONFIG_SOFT_SPI) += soft_spi.o
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COBJS-$(CONFIG_SH_SPI) += sh_spi.o
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248
drivers/spi/oc_tiny_spi.c
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248
drivers/spi/oc_tiny_spi.c
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@ -0,0 +1,248 @@
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/*
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* Opencore tiny_spi driver
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*
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* http://opencores.org/project,tiny_spi
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*
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* based on bfin_spi.c
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* Copyright (c) 2005-2008 Analog Devices Inc.
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* Copyright (C) 2010 Thomas Chou <thomas@wytron.com.tw>
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*
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* Licensed under the GPL-2 or later.
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*/
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#include <common.h>
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#include <asm/io.h>
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#include <malloc.h>
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#include <spi.h>
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#include <asm/gpio.h>
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#define TINY_SPI_STATUS_TXE 0x1
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#define TINY_SPI_STATUS_TXR 0x2
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struct tiny_spi_regs {
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unsigned rxdata; /* Rx data reg */
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unsigned txdata; /* Tx data reg */
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unsigned status; /* Status reg */
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unsigned control; /* Control reg */
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unsigned baud; /* Baud reg */
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};
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struct tiny_spi_host {
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uint base;
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uint freq;
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uint baudwidth;
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};
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static const struct tiny_spi_host tiny_spi_host_list[] =
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CONFIG_SYS_TINY_SPI_LIST;
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struct tiny_spi_slave {
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struct spi_slave slave;
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const struct tiny_spi_host *host;
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uint mode;
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uint baud;
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uint flg;
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};
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#define to_tiny_spi_slave(s) container_of(s, struct tiny_spi_slave, slave)
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int spi_cs_is_valid(unsigned int bus, unsigned int cs)
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{
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return bus < ARRAY_SIZE(tiny_spi_host_list) && gpio_is_valid(cs);
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}
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void spi_cs_activate(struct spi_slave *slave)
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{
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struct tiny_spi_slave *tiny_spi = to_tiny_spi_slave(slave);
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unsigned int cs = slave->cs;
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gpio_set_value(cs, tiny_spi->flg);
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debug("%s: SPI_CS_GPIO:%x\n", __func__, gpio_get_value(cs));
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}
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void spi_cs_deactivate(struct spi_slave *slave)
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{
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struct tiny_spi_slave *tiny_spi = to_tiny_spi_slave(slave);
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unsigned int cs = slave->cs;
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gpio_set_value(cs, !tiny_spi->flg);
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debug("%s: SPI_CS_GPIO:%x\n", __func__, gpio_get_value(cs));
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}
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void spi_set_speed(struct spi_slave *slave, uint hz)
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{
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struct tiny_spi_slave *tiny_spi = to_tiny_spi_slave(slave);
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const struct tiny_spi_host *host = tiny_spi->host;
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tiny_spi->baud = min(DIV_ROUND_UP(host->freq, hz * 2),
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(1 << host->baudwidth)) - 1;
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debug("%s: speed %u actual %u\n", __func__, hz,
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host->freq / ((tiny_spi->baud + 1) * 2));
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}
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void spi_init(void)
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{
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}
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struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
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unsigned int hz, unsigned int mode)
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{
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struct tiny_spi_slave *tiny_spi;
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if (!spi_cs_is_valid(bus, cs) || gpio_request(cs, "tiny_spi"))
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return NULL;
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tiny_spi = malloc(sizeof(*tiny_spi));
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if (!tiny_spi)
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return NULL;
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memset(tiny_spi, 0, sizeof(*tiny_spi));
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tiny_spi->slave.bus = bus;
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tiny_spi->slave.cs = cs;
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tiny_spi->host = &tiny_spi_host_list[bus];
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tiny_spi->mode = mode & (SPI_CPOL | SPI_CPHA);
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tiny_spi->flg = mode & SPI_CS_HIGH ? 1 : 0;
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spi_set_speed(&tiny_spi->slave, hz);
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debug("%s: bus:%i cs:%i base:%lx\n", __func__,
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bus, cs, tiny_spi->host->base);
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return &tiny_spi->slave;
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}
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void spi_free_slave(struct spi_slave *slave)
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{
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struct tiny_spi_slave *tiny_spi = to_tiny_spi_slave(slave);
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gpio_free(slave->cs);
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free(tiny_spi);
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}
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int spi_claim_bus(struct spi_slave *slave)
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{
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struct tiny_spi_slave *tiny_spi = to_tiny_spi_slave(slave);
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struct tiny_spi_regs *regs = (void *)tiny_spi->host->base;
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debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
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gpio_direction_output(slave->cs, !tiny_spi->flg);
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writel(tiny_spi->mode, ®s->control);
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writel(tiny_spi->baud, ®s->baud);
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return 0;
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}
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void spi_release_bus(struct spi_slave *slave)
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{
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debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
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}
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#ifndef CONFIG_TINY_SPI_IDLE_VAL
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# define CONFIG_TINY_SPI_IDLE_VAL 0xff
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#endif
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int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
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void *din, unsigned long flags)
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{
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struct tiny_spi_slave *tiny_spi = to_tiny_spi_slave(slave);
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struct tiny_spi_regs *regs = (void *)tiny_spi->host->base;
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const u8 *txp = dout;
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u8 *rxp = din;
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uint bytes = bitlen / 8;
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uint i;
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debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__,
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slave->bus, slave->cs, bitlen, bytes, flags);
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if (bitlen == 0)
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goto done;
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/* assume to do 8 bits transfers */
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if (bitlen % 8) {
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flags |= SPI_XFER_END;
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goto done;
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}
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if (flags & SPI_XFER_BEGIN)
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spi_cs_activate(slave);
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/* we need to tighten the transfer loop */
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if (txp && rxp) {
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writeb(*txp++, ®s->txdata);
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if (bytes > 1) {
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writeb(*txp++, ®s->txdata);
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for (i = 2; i < bytes; i++) {
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u8 rx, tx = *txp++;
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while (!(readb(®s->status) &
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TINY_SPI_STATUS_TXR))
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;
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rx = readb(®s->txdata);
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writeb(tx, ®s->txdata);
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*rxp++ = rx;
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}
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while (!(readb(®s->status) &
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TINY_SPI_STATUS_TXR))
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;
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*rxp++ = readb(®s->txdata);
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}
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while (!(readb(®s->status) &
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TINY_SPI_STATUS_TXE))
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;
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*rxp++ = readb(®s->rxdata);
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} else if (rxp) {
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writeb(CONFIG_TINY_SPI_IDLE_VAL, ®s->txdata);
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if (bytes > 1) {
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writeb(CONFIG_TINY_SPI_IDLE_VAL,
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®s->txdata);
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for (i = 2; i < bytes; i++) {
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u8 rx;
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while (!(readb(®s->status) &
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TINY_SPI_STATUS_TXR))
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;
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rx = readb(®s->txdata);
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writeb(CONFIG_TINY_SPI_IDLE_VAL,
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®s->txdata);
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*rxp++ = rx;
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}
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while (!(readb(®s->status) &
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TINY_SPI_STATUS_TXR))
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;
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*rxp++ = readb(®s->txdata);
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}
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while (!(readb(®s->status) &
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TINY_SPI_STATUS_TXE))
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;
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*rxp++ = readb(®s->rxdata);
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} else if (txp) {
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writeb(*txp++, ®s->txdata);
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if (bytes > 1) {
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writeb(*txp++, ®s->txdata);
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for (i = 2; i < bytes; i++) {
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u8 tx = *txp++;
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while (!(readb(®s->status) &
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TINY_SPI_STATUS_TXR))
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;
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writeb(tx, ®s->txdata);
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}
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}
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while (!(readb(®s->status) &
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TINY_SPI_STATUS_TXE))
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;
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} else {
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writeb(CONFIG_TINY_SPI_IDLE_VAL, ®s->txdata);
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if (bytes > 1) {
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writeb(CONFIG_TINY_SPI_IDLE_VAL,
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®s->txdata);
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for (i = 2; i < bytes; i++) {
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while (!(readb(®s->status) &
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TINY_SPI_STATUS_TXR))
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;
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writeb(CONFIG_TINY_SPI_IDLE_VAL,
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®s->txdata);
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}
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}
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while (!(readb(®s->status) &
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TINY_SPI_STATUS_TXE))
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;
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}
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done:
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if (flags & SPI_XFER_END)
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spi_cs_deactivate(slave);
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return 0;
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}
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