diff options
Diffstat (limited to 'drivers/spi/mxc_spi.c')
| -rw-r--r-- | drivers/spi/mxc_spi.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c new file mode 100644 index 0000000..b2e3ab9 --- /dev/null +++ b/drivers/spi/mxc_spi.c @@ -0,0 +1,166 @@ +/* + * Copyright (C) 2008, Guennadi Liakhovetski <lg@denx.de> + * + * 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 <common.h> +#include <spi.h> +#include <asm/io.h> + +#ifdef CONFIG_MX27 +/* i.MX27 has a completely wrong register layout and register definitions in the + * datasheet, the correct one is in the Freescale's Linux driver */ + +#error "i.MX27 CSPI not supported due to drastic differences in register definisions" \ +"See linux mxc_spi driver from Freescale for details." + +#else + +#define MXC_CSPIRXDATA 0x00 +#define MXC_CSPITXDATA 0x04 +#define MXC_CSPICTRL 0x08 +#define MXC_CSPIINT 0x0C +#define MXC_CSPIDMA 0x10 +#define MXC_CSPISTAT 0x14 +#define MXC_CSPIPERIOD 0x18 +#define MXC_CSPITEST 0x1C +#define MXC_CSPIRESET 0x00 + +#define MXC_CSPICTRL_EN (1 << 0) +#define MXC_CSPICTRL_MODE (1 << 1) +#define MXC_CSPICTRL_XCH (1 << 2) +#define MXC_CSPICTRL_SMC (1 << 3) +#define MXC_CSPICTRL_POL (1 << 4) +#define MXC_CSPICTRL_PHA (1 << 5) +#define MXC_CSPICTRL_SSCTL (1 << 6) +#define MXC_CSPICTRL_SSPOL (1 << 7) +#define MXC_CSPICTRL_CHIPSELECT(x) (((x) & 0x3) << 24) +#define MXC_CSPICTRL_BITCOUNT(x) (((x) & 0x1f) << 8) +#define MXC_CSPICTRL_DATARATE(x) (((x) & 0x7) << 16) + +#define MXC_CSPIPERIOD_32KHZ (1 << 15) + +static unsigned long spi_bases[] = { + 0x43fa4000, + 0x50010000, + 0x53f84000, +}; + +static unsigned long spi_base; + +#endif + +spi_chipsel_type spi_chipsel[] = { + (spi_chipsel_type)0, + (spi_chipsel_type)1, + (spi_chipsel_type)2, + (spi_chipsel_type)3, +}; +int spi_chipsel_cnt = sizeof(spi_chipsel) / sizeof(spi_chipsel[0]); + +static inline u32 reg_read(unsigned long addr) +{ + return *(volatile unsigned long*)addr; +} + +static inline void reg_write(unsigned long addr, u32 val) +{ + *(volatile unsigned long*)addr = val; +} + +static u32 spi_xchg_single(u32 data, int bitlen) +{ + + unsigned int cfg_reg = reg_read(spi_base + MXC_CSPICTRL); + + if (MXC_CSPICTRL_BITCOUNT(bitlen - 1) != (cfg_reg & MXC_CSPICTRL_BITCOUNT(31))) { + cfg_reg = (cfg_reg & ~MXC_CSPICTRL_BITCOUNT(31)) | + MXC_CSPICTRL_BITCOUNT(bitlen - 1); + reg_write(spi_base + MXC_CSPICTRL, cfg_reg); + } + + reg_write(spi_base + MXC_CSPITXDATA, data); + + cfg_reg |= MXC_CSPICTRL_XCH; + + reg_write(spi_base + MXC_CSPICTRL, cfg_reg); + + while (reg_read(spi_base + MXC_CSPICTRL) & MXC_CSPICTRL_XCH) + ; + + return reg_read(spi_base + MXC_CSPIRXDATA); +} + +int spi_xfer(spi_chipsel_type chipsel, int bitlen, uchar *dout, uchar *din) +{ + int n_blks = (bitlen + 31) / 32; + u32 *out_l, *in_l; + int i; + + if ((int)dout & 3 || (int)din & 3) { + printf("Error: unaligned buffers in: %p, out: %p\n", din, dout); + return 1; + } + + if (!spi_base) + spi_select(CONFIG_MXC_SPI_IFACE, (int)chipsel, SPI_MODE_2 | SPI_CS_HIGH); + + for (i = 0, in_l = (u32 *)din, out_l = (u32 *)dout; + i < n_blks; + i++, in_l++, out_l++, bitlen -= 32) + *in_l = spi_xchg_single(*out_l, bitlen); + + return 0; +} + +void spi_init(void) +{ +} + +int spi_select(unsigned int bus, unsigned int dev, unsigned long mode) +{ + unsigned int ctrl_reg; + + if (bus >= sizeof(spi_bases) / sizeof(spi_bases[0]) || + dev > 3) + return 1; + + spi_base = spi_bases[bus]; + + ctrl_reg = MXC_CSPICTRL_CHIPSELECT(dev) | + MXC_CSPICTRL_BITCOUNT(31) | + MXC_CSPICTRL_DATARATE(7) | /* FIXME: calculate data rate */ + MXC_CSPICTRL_EN | + MXC_CSPICTRL_MODE; + + if (mode & SPI_CPHA) + ctrl_reg |= MXC_CSPICTRL_PHA; + if (!(mode & SPI_CPOL)) + ctrl_reg |= MXC_CSPICTRL_POL; + if (mode & SPI_CS_HIGH) + ctrl_reg |= MXC_CSPICTRL_SSPOL; + + reg_write(spi_base + MXC_CSPIRESET, 1); + udelay(1); + reg_write(spi_base + MXC_CSPICTRL, ctrl_reg); + reg_write(spi_base + MXC_CSPIPERIOD, + MXC_CSPIPERIOD_32KHZ); + reg_write(spi_base + MXC_CSPIINT, 0); + + return 0; +} |