diff options
Diffstat (limited to 'drivers/spi/armada100_spi.c')
| -rw-r--r-- | drivers/spi/armada100_spi.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/drivers/spi/armada100_spi.c b/drivers/spi/armada100_spi.c new file mode 100644 index 0000000..7384c9c --- /dev/null +++ b/drivers/spi/armada100_spi.c @@ -0,0 +1,228 @@ +/* + * (C) Copyright 2011 + * eInfochips Ltd. <www.einfochips.com> + * Written-by: Ajay Bhargav <ajay.bhargav@einfochips.com> + * + * (C) Copyright 2009 + * Marvell Semiconductor <www.marvell.com> + * Based on SSP driver + * Written-by: Lei Wen <leiwen@marvell.com> + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, + * MA 02110-1301 USA + */ + + +#include <common.h> +#include <malloc.h> +#include <spi.h> + +#include <asm/io.h> +#include <asm/arch/spi.h> +#include <asm/gpio.h> + +#define to_armd_spi_slave(s) container_of(s, struct armd_spi_slave, slave) + +struct armd_spi_slave { + struct spi_slave slave; + struct ssp_reg *spi_reg; + u32 cr0, cr1; + u32 int_cr1; + u32 clear_sr; + const void *tx; + void *rx; + int gpio_cs_inverted; +}; + +static int spi_armd_write(struct armd_spi_slave *pss) +{ + int wait_timeout = SSP_FLUSH_NUM; + while (--wait_timeout && !(readl(&pss->spi_reg->sssr) & SSSR_TNF)) + ; + if (!wait_timeout) { + debug("%s: timeout error\n", __func__); + return -1; + } + + if (pss->tx != NULL) { + writel(*(u8 *)pss->tx, &pss->spi_reg->ssdr); + ++pss->tx; + } else { + writel(0, &pss->spi_reg->ssdr); + } + return 0; +} + +static int spi_armd_read(struct armd_spi_slave *pss) +{ + int wait_timeout = SSP_FLUSH_NUM; + while (--wait_timeout && !(readl(&pss->spi_reg->sssr) & SSSR_RNE)) + ; + if (!wait_timeout) { + debug("%s: timeout error\n", __func__); + return -1; + } + + if (pss->rx != NULL) { + *(u8 *)pss->rx = readl(&pss->spi_reg->ssdr); + ++pss->rx; + } else { + readl(&pss->spi_reg->ssdr); + } + return 0; +} + +static int spi_armd_flush(struct armd_spi_slave *pss) +{ + unsigned long limit = SSP_FLUSH_NUM; + + do { + while (readl(&pss->spi_reg->sssr) & SSSR_RNE) + readl(&pss->spi_reg->ssdr); + } while ((readl(&pss->spi_reg->sssr) & SSSR_BSY) && limit--); + + writel(SSSR_ROR, &pss->spi_reg->sssr); + + return limit; +} + +void spi_cs_activate(struct spi_slave *slave) +{ + struct armd_spi_slave *pss = to_armd_spi_slave(slave); + + gpio_set_value(slave->cs, pss->gpio_cs_inverted); +} + +void spi_cs_deactivate(struct spi_slave *slave) +{ + struct armd_spi_slave *pss = to_armd_spi_slave(slave); + + gpio_set_value(slave->cs, !pss->gpio_cs_inverted); +} + +struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, + unsigned int max_hz, unsigned int mode) +{ + struct armd_spi_slave *pss; + + pss = malloc(sizeof(*pss)); + if (!pss) + return NULL; + + pss->slave.bus = bus; + pss->slave.cs = cs; + pss->spi_reg = (struct ssp_reg *)SSP_REG_BASE(CONFIG_SYS_SSP_PORT); + + pss->cr0 = SSCR0_MOTO | SSCR0_DATASIZE(DEFAULT_WORD_LEN) | SSCR0_SSE; + + pss->cr1 = (SSCR1_RXTRESH(RX_THRESH_DEF) & SSCR1_RFT) | + (SSCR1_TXTRESH(TX_THRESH_DEF) & SSCR1_TFT); + pss->cr1 &= ~(SSCR1_SPO | SSCR1_SPH); + pss->cr1 |= (((mode & SPI_CPHA) != 0) ? SSCR1_SPH : 0) + | (((mode & SPI_CPOL) != 0) ? SSCR1_SPO : 0); + + pss->int_cr1 = SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE; + pss->clear_sr = SSSR_ROR | SSSR_TINT; + + pss->gpio_cs_inverted = mode & SPI_CS_HIGH; + gpio_set_value(cs, !pss->gpio_cs_inverted); + + return &pss->slave; +} + +void spi_free_slave(struct spi_slave *slave) +{ + struct armd_spi_slave *pss = to_armd_spi_slave(slave); + + free(pss); +} + +int spi_claim_bus(struct spi_slave *slave) +{ + struct armd_spi_slave *pss = to_armd_spi_slave(slave); + + debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs); + if (spi_armd_flush(pss) == 0) + return -1; + + return 0; +} + +void spi_release_bus(struct spi_slave *slave) +{ +} + +int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, + void *din, unsigned long flags) +{ + struct armd_spi_slave *pss = to_armd_spi_slave(slave); + uint bytes = bitlen / 8; + unsigned long limit; + int ret = 0; + + if (bitlen == 0) + goto done; + + /* we can only do 8 bit transfers */ + if (bitlen % 8) { + flags |= SPI_XFER_END; + goto done; + } + + if (dout) + pss->tx = dout; + else + pss->tx = NULL; + + if (din) + pss->rx = din; + else + pss->rx = NULL; + + if (flags & SPI_XFER_BEGIN) { + spi_cs_activate(slave); + writel(pss->cr1 | pss->int_cr1, &pss->spi_reg->sscr1); + writel(TIMEOUT_DEF, &pss->spi_reg->ssto); + writel(pss->cr0, &pss->spi_reg->sscr0); + } + + while (bytes--) { + limit = SSP_FLUSH_NUM; + ret = spi_armd_write(pss); + if (ret) + break; + + while ((readl(&pss->spi_reg->sssr) & SSSR_BSY) && limit--) + udelay(1); + + ret = spi_armd_read(pss); + if (ret) + break; + } + + done: + if (flags & SPI_XFER_END) { + /* Stop SSP */ + writel(pss->clear_sr, &pss->spi_reg->sssr); + clrbits_le32(&pss->spi_reg->sscr1, pss->int_cr1); + writel(0, &pss->spi_reg->ssto); + spi_cs_deactivate(slave); + } + + return ret; +} |