diff options
Diffstat (limited to 'drivers/spi/bfin_spi6xx.c')
| -rw-r--r-- | drivers/spi/bfin_spi6xx.c | 308 |
1 files changed, 308 insertions, 0 deletions
diff --git a/drivers/spi/bfin_spi6xx.c b/drivers/spi/bfin_spi6xx.c new file mode 100644 index 0000000..fde3447 --- /dev/null +++ b/drivers/spi/bfin_spi6xx.c @@ -0,0 +1,308 @@ +/* + * Analog Devices SPI3 controller driver + * + * Copyright (c) 2011 Analog Devices Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * 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., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <common.h> +#include <malloc.h> +#include <spi.h> + +#include <asm/blackfin.h> +#include <asm/gpio.h> +#include <asm/portmux.h> +#include <asm/mach-common/bits/spi6xx.h> + +struct bfin_spi_slave { + struct spi_slave slave; + u32 control, clock; + struct bfin_spi_regs *regs; + int cs_pol; +}; + +#define to_bfin_spi_slave(s) container_of(s, struct bfin_spi_slave, slave) + +#define gpio_cs(cs) ((cs) - MAX_CTRL_CS) +#ifdef CONFIG_BFIN_SPI_GPIO_CS +# define is_gpio_cs(cs) ((cs) > MAX_CTRL_CS) +#else +# define is_gpio_cs(cs) 0 +#endif + +int spi_cs_is_valid(unsigned int bus, unsigned int cs) +{ + if (is_gpio_cs(cs)) + return gpio_is_valid(gpio_cs(cs)); + else + return (cs >= 1 && cs <= MAX_CTRL_CS); +} + +void spi_cs_activate(struct spi_slave *slave) +{ + struct bfin_spi_slave *bss = to_bfin_spi_slave(slave); + + if (is_gpio_cs(slave->cs)) { + unsigned int cs = gpio_cs(slave->cs); + gpio_set_value(cs, bss->cs_pol); + } else { + u32 ssel; + ssel = bfin_read32(&bss->regs->ssel); + ssel |= 1 << slave->cs; + if (bss->cs_pol) + ssel |= (1 << 8) << slave->cs; + else + ssel &= ~((1 << 8) << slave->cs); + bfin_write32(&bss->regs->ssel, ssel); + } + + SSYNC(); +} + +void spi_cs_deactivate(struct spi_slave *slave) +{ + struct bfin_spi_slave *bss = to_bfin_spi_slave(slave); + + if (is_gpio_cs(slave->cs)) { + unsigned int cs = gpio_cs(slave->cs); + gpio_set_value(cs, !bss->cs_pol); + } else { + u32 ssel; + ssel = bfin_read32(&bss->regs->ssel); + if (bss->cs_pol) + ssel &= ~((1 << 8) << slave->cs); + else + ssel |= (1 << 8) << slave->cs; + /* deassert cs */ + bfin_write32(&bss->regs->ssel, ssel); + SSYNC(); + /* disable cs */ + ssel &= ~(1 << slave->cs); + bfin_write32(&bss->regs->ssel, ssel); + } + + SSYNC(); +} + +void spi_init() +{ +} + +#define SPI_PINS(n) \ + { 0, P_SPI##n##_SCK, P_SPI##n##_MISO, P_SPI##n##_MOSI, 0 } +static unsigned short pins[][5] = { +#ifdef SPI0_REGBASE + [0] = SPI_PINS(0), +#endif +#ifdef SPI1_REGBASE + [1] = SPI_PINS(1), +#endif +#ifdef SPI2_REGBASE + [2] = SPI_PINS(2), +#endif +}; + +#define SPI_CS_PINS(n) \ + { \ + P_SPI##n##_SSEL1, P_SPI##n##_SSEL2, P_SPI##n##_SSEL3, \ + P_SPI##n##_SSEL4, P_SPI##n##_SSEL5, P_SPI##n##_SSEL6, \ + P_SPI##n##_SSEL7, \ + } +static const unsigned short cs_pins[][7] = { +#ifdef SPI0_REGBASE + [0] = SPI_CS_PINS(0), +#endif +#ifdef SPI1_REGBASE + [1] = SPI_CS_PINS(1), +#endif +#ifdef SPI2_REGBASE + [2] = SPI_CS_PINS(2), +#endif +}; + +void spi_set_speed(struct spi_slave *slave, uint hz) +{ + struct bfin_spi_slave *bss = to_bfin_spi_slave(slave); + ulong sclk; + u32 clock; + + sclk = get_sclk1(); + clock = sclk / hz; + if (clock) + clock--; + bss->clock = clock; +} + +struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, + unsigned int max_hz, unsigned int mode) +{ + struct bfin_spi_slave *bss; + u32 reg_base; + + if (!spi_cs_is_valid(bus, cs)) + return NULL; + + if (bus >= ARRAY_SIZE(pins) || pins[bus] == NULL) { + debug("%s: invalid bus %u\n", __func__, bus); + return NULL; + } + switch (bus) { +#ifdef SPI0_REGBASE + case 0: + reg_base = SPI0_REGBASE; + break; +#endif +#ifdef SPI1_REGBASE + case 1: + reg_base = SPI1_REGBASE; + break; +#endif +#ifdef SPI2_REGBASE + case 2: + reg_base = SPI2_REGBASE; + break; +#endif + default: + return NULL; + } + + bss = malloc(sizeof(*bss)); + if (!bss) + return NULL; + + bss->slave.bus = bus; + bss->slave.cs = cs; + bss->regs = (struct bfin_spi_regs *)reg_base; + bss->control = SPI_CTL_EN | SPI_CTL_MSTR; + if (mode & SPI_CPHA) + bss->control |= SPI_CTL_CPHA; + if (mode & SPI_CPOL) + bss->control |= SPI_CTL_CPOL; + if (mode & SPI_LSB_FIRST) + bss->control |= SPI_CTL_LSBF; + bss->control &= ~SPI_CTL_ASSEL; + bss->cs_pol = mode & SPI_CS_HIGH ? 1 : 0; + spi_set_speed(&bss->slave, max_hz); + + return &bss->slave; +} + +void spi_free_slave(struct spi_slave *slave) +{ + struct bfin_spi_slave *bss = to_bfin_spi_slave(slave); + free(bss); +} + +int spi_claim_bus(struct spi_slave *slave) +{ + struct bfin_spi_slave *bss = to_bfin_spi_slave(slave); + + debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs); + + if (is_gpio_cs(slave->cs)) { + unsigned int cs = gpio_cs(slave->cs); + gpio_request(cs, "bfin-spi"); + gpio_direction_output(cs, !bss->cs_pol); + pins[slave->bus][0] = P_DONTCARE; + } else + pins[slave->bus][0] = cs_pins[slave->bus][slave->cs - 1]; + peripheral_request_list(pins[slave->bus], "bfin-spi"); + + bfin_write32(&bss->regs->control, bss->control); + bfin_write32(&bss->regs->clock, bss->clock); + bfin_write32(&bss->regs->delay, 0x0); + bfin_write32(&bss->regs->rx_control, SPI_RXCTL_REN); + bfin_write32(&bss->regs->tx_control, SPI_TXCTL_TEN | SPI_TXCTL_TTI); + SSYNC(); + + return 0; +} + +void spi_release_bus(struct spi_slave *slave) +{ + struct bfin_spi_slave *bss = to_bfin_spi_slave(slave); + + debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs); + + peripheral_free_list(pins[slave->bus]); + if (is_gpio_cs(slave->cs)) + gpio_free(gpio_cs(slave->cs)); + + bfin_write32(&bss->regs->rx_control, 0x0); + bfin_write32(&bss->regs->tx_control, 0x0); + bfin_write32(&bss->regs->control, 0x0); + SSYNC(); +} + +#ifndef CONFIG_BFIN_SPI_IDLE_VAL +# define CONFIG_BFIN_SPI_IDLE_VAL 0xff +#endif + +static int spi_pio_xfer(struct bfin_spi_slave *bss, const u8 *tx, u8 *rx, + uint bytes) +{ + /* discard invalid rx data and empty rfifo */ + while (!(bfin_read32(&bss->regs->status) & SPI_STAT_RFE)) + bfin_read32(&bss->regs->rfifo); + + while (bytes--) { + u8 value = (tx ? *tx++ : CONFIG_BFIN_SPI_IDLE_VAL); + debug("%s: tx:%x ", __func__, value); + bfin_write32(&bss->regs->tfifo, value); + SSYNC(); + while (bfin_read32(&bss->regs->status) & SPI_STAT_RFE) + if (ctrlc()) + return -1; + value = bfin_read32(&bss->regs->rfifo); + if (rx) + *rx++ = value; + debug("rx:%x\n", value); + } + + return 0; +} + +int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, + void *din, unsigned long flags) +{ + struct bfin_spi_slave *bss = to_bfin_spi_slave(slave); + const u8 *tx = dout; + u8 *rx = din; + uint bytes = bitlen / 8; + int ret = 0; + + debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__, + slave->bus, slave->cs, bitlen, bytes, flags); + + if (bitlen == 0) + goto done; + + /* we can only do 8 bit transfers */ + if (bitlen % 8) { + flags |= SPI_XFER_END; + goto done; + } + + if (flags & SPI_XFER_BEGIN) + spi_cs_activate(slave); + + ret = spi_pio_xfer(bss, tx, rx, bytes); + + done: + if (flags & SPI_XFER_END) + spi_cs_deactivate(slave); + + return ret; +} |