diff options
Diffstat (limited to 'qemu/roms/u-boot/drivers/spi/davinci_spi.c')
-rw-r--r-- | qemu/roms/u-boot/drivers/spi/davinci_spi.c | 321 |
1 files changed, 321 insertions, 0 deletions
diff --git a/qemu/roms/u-boot/drivers/spi/davinci_spi.c b/qemu/roms/u-boot/drivers/spi/davinci_spi.c new file mode 100644 index 000000000..28fb3a2e9 --- /dev/null +++ b/qemu/roms/u-boot/drivers/spi/davinci_spi.c @@ -0,0 +1,321 @@ +/* + * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/ + * + * Driver for SPI controller on DaVinci. Based on atmel_spi.c + * by Atmel Corporation + * + * Copyright (C) 2007 Atmel Corporation + * + * SPDX-License-Identifier: GPL-2.0+ + */ +#include <common.h> +#include <spi.h> +#include <malloc.h> +#include <asm/io.h> +#include <asm/arch/hardware.h> +#include "davinci_spi.h" + +void spi_init() +{ + /* do nothing */ +} + +struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, + unsigned int max_hz, unsigned int mode) +{ + struct davinci_spi_slave *ds; + + if (!spi_cs_is_valid(bus, cs)) + return NULL; + + ds = spi_alloc_slave(struct davinci_spi_slave, bus, cs); + if (!ds) + return NULL; + + ds->slave.bus = bus; + ds->slave.cs = cs; + + switch (bus) { + case SPI0_BUS: + ds->regs = (struct davinci_spi_regs *)SPI0_BASE; + break; +#ifdef CONFIG_SYS_SPI1 + case SPI1_BUS: + ds->regs = (struct davinci_spi_regs *)SPI0_BASE; + break; +#endif +#ifdef CONFIG_SYS_SPI2 + case SPI2_BUS: + ds->regs = (struct davinci_spi_regs *)SPI2_BASE; + break; +#endif + default: /* Invalid bus number */ + return NULL; + } + + ds->freq = max_hz; + + return &ds->slave; +} + +void spi_free_slave(struct spi_slave *slave) +{ + struct davinci_spi_slave *ds = to_davinci_spi(slave); + + free(ds); +} + +int spi_claim_bus(struct spi_slave *slave) +{ + struct davinci_spi_slave *ds = to_davinci_spi(slave); + unsigned int scalar; + + /* Enable the SPI hardware */ + writel(SPIGCR0_SPIRST_MASK, &ds->regs->gcr0); + udelay(1000); + writel(SPIGCR0_SPIENA_MASK, &ds->regs->gcr0); + + /* Set master mode, powered up and not activated */ + writel(SPIGCR1_MASTER_MASK | SPIGCR1_CLKMOD_MASK, &ds->regs->gcr1); + + /* CS, CLK, SIMO and SOMI are functional pins */ + writel(((1 << slave->cs) | SPIPC0_CLKFUN_MASK | + SPIPC0_DOFUN_MASK | SPIPC0_DIFUN_MASK), &ds->regs->pc0); + + /* setup format */ + scalar = ((CONFIG_SYS_SPI_CLK / ds->freq) - 1) & 0xFF; + + /* + * Use following format: + * character length = 8, + * clock signal delayed by half clk cycle, + * clock low in idle state - Mode 0, + * MSB shifted out first + */ + writel(8 | (scalar << SPIFMT_PRESCALE_SHIFT) | + (1 << SPIFMT_PHASE_SHIFT), &ds->regs->fmt0); + + /* + * Including a minor delay. No science here. Should be good even with + * no delay + */ + writel((50 << SPI_C2TDELAY_SHIFT) | + (50 << SPI_T2CDELAY_SHIFT), &ds->regs->delay); + + /* default chip select register */ + writel(SPIDEF_CSDEF0_MASK, &ds->regs->def); + + /* no interrupts */ + writel(0, &ds->regs->int0); + writel(0, &ds->regs->lvl); + + /* enable SPI */ + writel((readl(&ds->regs->gcr1) | SPIGCR1_SPIENA_MASK), &ds->regs->gcr1); + + return 0; +} + +void spi_release_bus(struct spi_slave *slave) +{ + struct davinci_spi_slave *ds = to_davinci_spi(slave); + + /* Disable the SPI hardware */ + writel(SPIGCR0_SPIRST_MASK, &ds->regs->gcr0); +} + +/* + * This functions needs to act like a macro to avoid pipeline reloads in the + * loops below. Use always_inline. This gains us about 160KiB/s and the bloat + * appears to be zero bytes (da830). + */ +__attribute__((always_inline)) +static inline u32 davinci_spi_xfer_data(struct davinci_spi_slave *ds, u32 data) +{ + u32 buf_reg_val; + + /* send out data */ + writel(data, &ds->regs->dat1); + + /* wait for the data to clock in/out */ + while ((buf_reg_val = readl(&ds->regs->buf)) & SPIBUF_RXEMPTY_MASK) + ; + + return buf_reg_val; +} + +static int davinci_spi_read(struct spi_slave *slave, unsigned int len, + u8 *rxp, unsigned long flags) +{ + struct davinci_spi_slave *ds = to_davinci_spi(slave); + unsigned int data1_reg_val; + + /* enable CS hold, CS[n] and clear the data bits */ + data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) | + (slave->cs << SPIDAT1_CSNR_SHIFT)); + + /* wait till TXFULL is deasserted */ + while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK) + ; + + /* preload the TX buffer to avoid clock starvation */ + writel(data1_reg_val, &ds->regs->dat1); + + /* keep reading 1 byte until only 1 byte left */ + while ((len--) > 1) + *rxp++ = davinci_spi_xfer_data(ds, data1_reg_val); + + /* clear CS hold when we reach the end */ + if (flags & SPI_XFER_END) + data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT); + + /* read the last byte */ + *rxp = davinci_spi_xfer_data(ds, data1_reg_val); + + return 0; +} + +static int davinci_spi_write(struct spi_slave *slave, unsigned int len, + const u8 *txp, unsigned long flags) +{ + struct davinci_spi_slave *ds = to_davinci_spi(slave); + unsigned int data1_reg_val; + + /* enable CS hold and clear the data bits */ + data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) | + (slave->cs << SPIDAT1_CSNR_SHIFT)); + + /* wait till TXFULL is deasserted */ + while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK) + ; + + /* preload the TX buffer to avoid clock starvation */ + if (len > 2) { + writel(data1_reg_val | *txp++, &ds->regs->dat1); + len--; + } + + /* keep writing 1 byte until only 1 byte left */ + while ((len--) > 1) + davinci_spi_xfer_data(ds, data1_reg_val | *txp++); + + /* clear CS hold when we reach the end */ + if (flags & SPI_XFER_END) + data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT); + + /* write the last byte */ + davinci_spi_xfer_data(ds, data1_reg_val | *txp); + + return 0; +} + +#ifndef CONFIG_SPI_HALF_DUPLEX +static int davinci_spi_read_write(struct spi_slave *slave, unsigned int len, + u8 *rxp, const u8 *txp, unsigned long flags) +{ + struct davinci_spi_slave *ds = to_davinci_spi(slave); + unsigned int data1_reg_val; + + /* enable CS hold and clear the data bits */ + data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) | + (slave->cs << SPIDAT1_CSNR_SHIFT)); + + /* wait till TXFULL is deasserted */ + while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK) + ; + + /* keep reading and writing 1 byte until only 1 byte left */ + while ((len--) > 1) + *rxp++ = davinci_spi_xfer_data(ds, data1_reg_val | *txp++); + + /* clear CS hold when we reach the end */ + if (flags & SPI_XFER_END) + data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT); + + /* read and write the last byte */ + *rxp = davinci_spi_xfer_data(ds, data1_reg_val | *txp); + + return 0; +} +#endif + +int spi_xfer(struct spi_slave *slave, unsigned int bitlen, + const void *dout, void *din, unsigned long flags) +{ + unsigned int len; + + if (bitlen == 0) + /* Finish any previously submitted transfers */ + goto out; + + /* + * It's not clear how non-8-bit-aligned transfers are supposed to be + * represented as a stream of bytes...this is a limitation of + * the current SPI interface - here we terminate on receiving such a + * transfer request. + */ + if (bitlen % 8) { + /* Errors always terminate an ongoing transfer */ + flags |= SPI_XFER_END; + goto out; + } + + len = bitlen / 8; + + if (!dout) + return davinci_spi_read(slave, len, din, flags); + else if (!din) + return davinci_spi_write(slave, len, dout, flags); +#ifndef CONFIG_SPI_HALF_DUPLEX + else + return davinci_spi_read_write(slave, len, din, dout, flags); +#else + printf("SPI full duplex transaction requested with " + "CONFIG_SPI_HALF_DUPLEX defined.\n"); + flags |= SPI_XFER_END; +#endif + +out: + if (flags & SPI_XFER_END) { + u8 dummy = 0; + davinci_spi_write(slave, 1, &dummy, flags); + } + return 0; +} + +int spi_cs_is_valid(unsigned int bus, unsigned int cs) +{ + int ret = 0; + + switch (bus) { + case SPI0_BUS: + if (cs < SPI0_NUM_CS) + ret = 1; + break; +#ifdef CONFIG_SYS_SPI1 + case SPI1_BUS: + if (cs < SPI1_NUM_CS) + ret = 1; + break; +#endif +#ifdef CONFIG_SYS_SPI2 + case SPI2_BUS: + if (cs < SPI2_NUM_CS) + ret = 1; + break; +#endif + default: + /* Invalid bus number. Do nothing */ + break; + } + return ret; +} + +void spi_cs_activate(struct spi_slave *slave) +{ + /* do nothing */ +} + +void spi_cs_deactivate(struct spi_slave *slave) +{ + /* do nothing */ +} |