diff options
Diffstat (limited to 'drivers/spi/imx_spi.c')
| -rw-r--r-- | drivers/spi/imx_spi.c | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/drivers/spi/imx_spi.c b/drivers/spi/imx_spi.c new file mode 100644 index 0000000..6146da9 --- /dev/null +++ b/drivers/spi/imx_spi.c @@ -0,0 +1,329 @@ +/* + * (C) Copyright 2008-2009 Freescale Semiconductor, Inc. + * + * 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., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <config.h> +#include <common.h> +#include <spi.h> +#include <asm/errno.h> +#include <linux/types.h> +#include <asm/io.h> +#include <malloc.h> + +#include <asm/arch/imx_spi.h> + +#ifdef DEBUG + +/* ----------------------------------------------- + * Helper functions to peek into tx and rx buffers + * ----------------------------------------------- */ +static const char * const hex_digit = "0123456789ABCDEF"; + +static char quickhex(int i) +{ + return hex_digit[i]; +} + +static void memdump(const void *pv, int num) +{ + +} + +#else /* !DEBUG */ + +#define memdump(p, n) + +#endif /* DEBUG */ + +static inline struct imx_spi_dev_t *to_imx_spi_slave(struct spi_slave *slave) +{ + return container_of(slave, struct imx_spi_dev_t, slave); +} + +static s32 spi_get_cfg(struct imx_spi_dev_t *dev) +{ + switch (dev->slave.cs) { + case 0: + /* pmic */ + dev->base = CSPI1_BASE_ADDR; + dev->freq = 2500000; + dev->ss_pol = IMX_SPI_ACTIVE_HIGH; + dev->ss = 0; + dev->fifo_sz = 64 * 4; + dev->us_delay = 0; + break; + case 1: + /* spi_nor */ + dev->base = CSPI1_BASE_ADDR; + dev->freq = 2500000; + dev->ss_pol = IMX_SPI_ACTIVE_LOW; + dev->ss = 1; + dev->fifo_sz = 64 * 4; + dev->us_delay = 0; + break; + default: + printf("Invalid Bus ID! \n"); + break; + } + + return 0; +} + +static s32 spi_reset(struct spi_slave *slave) +{ + u32 clk_src = mxc_get_clock(MXC_CSPI_CLK); + s32 pre_div = 0, post_div = 0, i, reg_ctrl, reg_config; + struct imx_spi_dev_t *dev = to_imx_spi_slave(slave); + struct spi_reg_t *reg = &(dev->reg); + + if (dev->freq == 0) { + printf("Error: desired clock is 0\n"); + return 1; + } + + reg_ctrl = readl(dev->base + SPI_CON_REG); + /* Reset spi */ + writel(0, dev->base + SPI_CON_REG); + writel((reg_ctrl | 0x1), dev->base + SPI_CON_REG); + + /* Control register setup */ + if (clk_src > dev->freq) { + pre_div = clk_src / dev->freq; + if (pre_div > 16) { + post_div = pre_div / 16; + pre_div = 15; + } + if (post_div != 0) { + for (i = 0; i < 16; i++) { + if ((1 << i) >= post_div) + break; + } + if (i == 16) { + printf("Error: no divider can meet the freq: %d\n", + dev->freq); + return -1; + } + post_div = i; + } + } + + debug("pre_div = %d, post_div=%d\n", pre_div, post_div); + reg_ctrl = (reg_ctrl & ~(3 << 18)) | dev->ss << 18; + reg_ctrl = (reg_ctrl & ~(0xF << 12)) | pre_div << 12; + reg_ctrl = (reg_ctrl & ~(0xF << 8)) | post_div << 8; + reg_ctrl |= 1 << (dev->ss + 4); /* always set to master mode !!!! */ + reg_ctrl &= ~0x1; /* disable spi */ + + reg_config = readl(dev->base + SPI_CFG_REG); + /* configuration register setup */ + reg_config = (reg_config & ~(1 << ((dev->ss + 12)))) | + (dev->ss_pol << (dev->ss + 12)); + reg_config = (reg_config & ~(1 << ((dev->ss + 20)))) | + (dev->in_sctl << (dev->ss + 20)); + reg_config = (reg_config & ~(1 << ((dev->ss + 16)))) | + (dev->in_dctl << (dev->ss + 16)); + reg_config = (reg_config & ~(1 << ((dev->ss + 8)))) | + (dev->ssctl << (dev->ss + 8)); + reg_config = (reg_config & ~(1 << ((dev->ss + 4)))) | + (dev->sclkpol << (dev->ss + 4)); + reg_config = (reg_config & ~(1 << ((dev->ss + 0)))) | + (dev->sclkpha << (dev->ss + 0)); + + debug("reg_ctrl = 0x%x\n", reg_ctrl); + writel(reg_ctrl, dev->base + SPI_CON_REG); + debug("reg_config = 0x%x\n", reg_config); + writel(reg_config, dev->base + SPI_CFG_REG); + + /* save config register and control register */ + reg->cfg_reg = reg_config; + reg->ctrl_reg = reg_ctrl; + + /* clear interrupt reg */ + writel(0, dev->base + SPI_INT_REG); + writel(3 << 6, dev->base + SPI_STAT_REG); + + return 0; +} + +void spi_init(void) +{ +} + +struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, + unsigned int max_hz, unsigned int mode) +{ + struct imx_spi_dev_t *imx_spi_slave = NULL; + + if (!spi_cs_is_valid(bus, cs)) + return NULL; + + imx_spi_slave = (struct imx_spi_dev_t *)malloc(sizeof(struct imx_spi_dev_t)); + if (!imx_spi_slave) + return NULL; + + imx_spi_slave->slave.bus = bus; + imx_spi_slave->slave.cs = cs; + + spi_get_cfg(imx_spi_slave); + + spi_io_init(imx_spi_slave); + + spi_reset(&(imx_spi_slave->slave)); + + return &(imx_spi_slave->slave); +} + +void spi_free_slave(struct spi_slave *slave) +{ + struct imx_spi_dev_t *imx_spi_slave; + + if (slave) { + imx_spi_slave = to_imx_spi_slave(slave); + free(imx_spi_slave); + } +} + +int spi_claim_bus(struct spi_slave *slave) +{ + return 0; +} + +void spi_release_bus(struct spi_slave *slave) +{ + +} + +/* + * SPI transfer: + * + * See include/spi.h and http://www.altera.com/literature/ds/ds_nios_spi.pdf + * for more informations. + */ +int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, + void *din, unsigned long flags) +{ + s32 val = SPI_RETRY_TIMES; + u32 *p_buf; + u32 reg; + s32 len = 0, + ret_val = 0; + s32 burst_bytes = bitlen >> 3; + s32 tmp = 0; + struct imx_spi_dev_t *dev = to_imx_spi_slave(slave); + struct spi_reg_t *spi_reg = &(dev->reg); + + if (!slave) + return -1; + + if (burst_bytes > (MAX_SPI_BYTES)) { + printf("Error: maximum burst size is 0x%x bytes, asking 0x%x\n", + MAX_SPI_BYTES, burst_bytes); + return -1; + } + + if (flags & SPI_XFER_BEGIN) { + spi_cs_activate(slave); + + if (spi_reg->ctrl_reg == 0) { + printf("Error: spi(base=0x%x) has not been initialized yet\n", + dev->base); + return -1; + } + spi_reg->ctrl_reg = (spi_reg->ctrl_reg & ~0xFFF00000) | \ + ((burst_bytes * 8 - 1) << 20); + + writel(spi_reg->ctrl_reg | 0x1, dev->base + SPI_CON_REG); + writel(spi_reg->cfg_reg, dev->base + SPI_CFG_REG); + debug("ctrl_reg=0x%x, cfg_reg=0x%x\n", + readl(dev->base + SPI_CON_REG), + readl(dev->base + SPI_CFG_REG)); + + /* move data to the tx fifo */ + if (dout) { + for (p_buf = (u32 *)dout, len = burst_bytes; len > 0; + p_buf++, len -= 4) + writel(*p_buf, dev->base + SPI_TX_DATA); + } else { + for (len = burst_bytes; len > 0; len -= 4) + writel(tmp, dev->base + SPI_TX_DATA); + } + + reg = readl(dev->base + SPI_CON_REG); + reg |= (1 << 2); /* set xch bit */ + debug("control reg = 0x%08x\n", reg); + writel(reg, dev->base + SPI_CON_REG); + + /* poll on the TC bit (transfer complete) */ + while ((val-- > 0) && + (readl(dev->base + SPI_STAT_REG) & (1 << 7)) == 0) { + udelay(100); + } + + /* clear the TC bit */ + writel(3 << 6, dev->base + SPI_STAT_REG); + if (val <= 0) { + printf("Error: re-tried %d times without response. Give up\n", + SPI_RETRY_TIMES); + ret_val = -1; + goto error; + } + } + + /* move data in the rx buf */ + if (flags & SPI_XFER_END) { + if (din) { + for (p_buf = (u32 *)din, len = burst_bytes; len > 0; + ++p_buf, len -= 4) + *p_buf = readl(dev->base + SPI_RX_DATA); + } else { + for (len = burst_bytes; len > 0; len -= 4) + tmp = readl(dev->base + SPI_RX_DATA); + } + + spi_cs_deactivate(slave); + } + + return ret_val; + +error: + spi_cs_deactivate(slave); + return ret_val; +} + +int spi_cs_is_valid(unsigned int bus, unsigned int cs) +{ + return 1; +} + +void spi_cs_activate(struct spi_slave *slave) +{ + struct imx_spi_dev_t *dev = to_imx_spi_slave(slave); + + spi_io_init(dev); +} + +void spi_cs_deactivate(struct spi_slave *slave) +{ + struct imx_spi_dev_t *dev = to_imx_spi_slave(slave); + + writel(0, dev->base + SPI_CON_REG); +} + |