Signed-off-by: Antony Pavlov <antonynpavlov@xxxxxxxxx> --- drivers/spi/Kconfig | 3 + drivers/spi/Makefile | 1 + drivers/spi/litex_spiflash.c | 241 +++++++++++++++++++++++++++++++++++ 3 files changed, 245 insertions(+) diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 91083ee709..e92cf675ab 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -74,6 +74,9 @@ config DRIVER_SPI_IMX_2_3 depends on ARCH_IMX50 || ARCH_IMX51 || ARCH_IMX53 || ARCH_IMX6 || ARCH_IMX7 || ARCH_IMX8M default y +config DRIVER_SPI_LITEX_SPIFLASH + bool "Litex SPIFLASH bitbang master driver" + config DRIVER_SPI_MXS bool "i.MX (23,28) SPI Master driver" depends on ARCH_IMX28 diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 908d514a01..ac95ffc1db 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -4,6 +4,7 @@ obj-$(CONFIG_DRIVER_SPI_ATH79) += ath79_spi.o obj-$(CONFIG_DRIVER_SPI_GPIO) += gpio_spi.o obj-$(CONFIG_DRIVER_SPI_FSL_QUADSPI) += spi-fsl-qspi.o obj-$(CONFIG_DRIVER_SPI_IMX) += imx_spi.o +obj-$(CONFIG_DRIVER_SPI_LITEX_SPIFLASH) += litex_spiflash.o obj-$(CONFIG_DRIVER_SPI_MVEBU) += mvebu_spi.o obj-$(CONFIG_DRIVER_SPI_MXS) += mxs_spi.o obj-$(CONFIG_DRIVER_SPI_ALTERA) += altera_spi.o diff --git a/drivers/spi/litex_spiflash.c b/drivers/spi/litex_spiflash.c new file mode 100644 index 0000000000..26ef207699 --- /dev/null +++ b/drivers/spi/litex_spiflash.c @@ -0,0 +1,241 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2020 Antony Pavlov <antonynpavlov@xxxxxxxxx> + * + */ + +#include <common.h> +#include <init.h> +#include <driver.h> +#include <spi/spi.h> +#include <io.h> + +struct litex_spiflash_spi { + struct spi_master master; + void __iomem *regs; + u32 val; +}; + +#define SPIFLASH_BITBANG 0x0 +#define SPIFLASH_BB_MOSI BIT(0) +#define SPIFLASH_BB_CLK BIT(1) +#define SPIFLASH_BB_CSN BIT(2) +#define SPIFLASH_BB_DIR BIT(3) + +#define SPIFLASH_MISO 0x4 +#define SPIFLASH_BITBANG_EN 0x8 + +static inline u32 litex_spiflash_spi_rr(struct litex_spiflash_spi *sp, int reg) +{ + return readl(sp->regs + reg); +} + +static inline void litex_spiflash_spi_wr(struct litex_spiflash_spi *sp, u32 val, int reg) +{ + writel(val, sp->regs + reg); +} + +static inline void setbits(struct litex_spiflash_spi *sp, int bits, int on) +{ + /* + * We are the only user of SCSPTR so no locking is required. + * Reading bit 2 and 0 in SCSPTR gives pin state as input. + * Writing the same bits sets the output value. + * This makes regular read-modify-write difficult so we + * use sp->val to keep track of the latest register value. + */ + + if (on) + sp->val |= bits; + else + sp->val &= ~bits; + + litex_spiflash_spi_wr(sp, sp->val, SPIFLASH_BITBANG); +} + +static inline struct litex_spiflash_spi *litex_spiflash_spidev_to_sp(struct spi_device *spi) +{ + return container_of(spi->master, struct litex_spiflash_spi, master); +} + +static inline void setsck(struct spi_device *spi, int on) +{ + struct litex_spiflash_spi *sc = litex_spiflash_spidev_to_sp(spi); + + setbits(sc, SPIFLASH_BB_CLK, on); +} + +static inline void setmosi(struct spi_device *spi, int on) +{ + struct litex_spiflash_spi *sc = litex_spiflash_spidev_to_sp(spi); + + sc->val &= ~SPIFLASH_BB_DIR; + setbits(sc, SPIFLASH_BB_MOSI, on); +} + +static inline u32 getmiso(struct spi_device *spi) +{ + struct litex_spiflash_spi *sc = litex_spiflash_spidev_to_sp(spi); + + setbits(sc, SPIFLASH_BB_DIR, 1); + return !!((litex_spiflash_spi_rr(sc, SPIFLASH_MISO) & 1)); +} + +#define spidelay(nsecs) udelay(nsecs/1000) + +#include "spi-bitbang-txrx.h" + +static inline void litex_spiflash_spi_chipselect(struct litex_spiflash_spi *sc, int on) +{ + setbits(sc, SPIFLASH_BB_CSN, on); +} + +static int litex_spiflash_spi_setup(struct spi_device *spi) +{ + struct spi_master *master = spi->master; + struct device_d spi_dev = spi->dev; + + if (spi->bits_per_word != 8) { + dev_err(master->dev, "master doesn't support %d bits per word requested by %s\n", + spi->bits_per_word, spi_dev.name); + return -EINVAL; + } + + if ((spi->mode & (SPI_CPHA | SPI_CPOL)) != SPI_MODE_0) { + dev_err(master->dev, "master doesn't support SPI_MODE%d requested by %s\n", + spi->mode & (SPI_CPHA | SPI_CPOL), spi_dev.name); + return -EINVAL; + } + + return 0; +} + +static int litex_spiflash_spi_read(struct spi_device *spi, void *buf, size_t nbyte) +{ + ssize_t cnt = 0; + u8 *rxf_buf = buf; + + while (cnt < nbyte) { + *rxf_buf = bitbang_txrx_be_cpha1(spi, 1000, 1, 0, 8); + rxf_buf++; + cnt++; + } + + return cnt; +} + +static int litex_spiflash_spi_write(struct spi_device *spi, + const void *buf, size_t nbyte) +{ + ssize_t cnt = 0; + const u8 *txf_buf = buf; + + while (cnt < nbyte) { + bitbang_txrx_be_cpha1(spi, 1000, 1, (u32)*txf_buf, 8); + txf_buf++; + cnt++; + } + + return 0; +} + +static int litex_spiflash_spi_transfer(struct spi_device *spi, struct spi_message *mesg) +{ + struct litex_spiflash_spi *sc = litex_spiflash_spidev_to_sp(spi); + struct spi_transfer *t; + + mesg->actual_length = 0; + + /* activate chip select signal */ + litex_spiflash_spi_chipselect(sc, 0); + + list_for_each_entry(t, &mesg->transfers, transfer_list) { + + if (t->tx_buf) + litex_spiflash_spi_write(spi, t->tx_buf, t->len); + + if (t->rx_buf) + litex_spiflash_spi_read(spi, t->rx_buf, t->len); + + mesg->actual_length += t->len; + } + + /* inactivate chip select signal */ + litex_spiflash_spi_chipselect(sc, 1); + + return 0; +} + +static void litex_spiflash_spi_enable(struct litex_spiflash_spi *sp) +{ + u32 val; + + /* set SPIFLASH_BB_DIR = 0 */ + val = SPIFLASH_BB_CSN | SPIFLASH_BB_CLK | SPIFLASH_BB_MOSI; + litex_spiflash_spi_wr(sp, val, SPIFLASH_BITBANG); + + /* enable GPIO mode */ + litex_spiflash_spi_wr(sp, 1, SPIFLASH_BITBANG_EN); +} + +static void litex_spiflash_spi_disable(struct litex_spiflash_spi *sp) +{ + /* disable GPIO mode */ + litex_spiflash_spi_wr(sp, 0, SPIFLASH_BITBANG_EN); +} + +static int litex_spiflash_spi_probe(struct device_d *dev) +{ + struct resource *iores; + struct spi_master *master; + struct litex_spiflash_spi *litex_spiflash_spi; + + litex_spiflash_spi = xzalloc(sizeof(*litex_spiflash_spi)); + dev->priv = litex_spiflash_spi; + + master = &litex_spiflash_spi->master; + master->dev = dev; + + master->bus_num = dev->id; + master->setup = litex_spiflash_spi_setup; + master->transfer = litex_spiflash_spi_transfer; + master->num_chipselect = 1; + + iores = dev_request_mem_resource(dev, 0); + if (IS_ERR(iores)) + return PTR_ERR(iores); + litex_spiflash_spi->regs = IOMEM(iores->start); + + litex_spiflash_spi_enable(litex_spiflash_spi); + + /* inactivate chip select signal */ + litex_spiflash_spi_chipselect(litex_spiflash_spi, 1); + + spi_register_master(master); + + return 0; +} + +static void litex_spiflash_spi_remove(struct device_d *dev) +{ + struct litex_spiflash_spi *sp = dev->priv; + + litex_spiflash_spi_disable(sp); +} + +static __maybe_unused struct of_device_id litex_spiflash_spi_dt_ids[] = { + { + .compatible = "litex,spiflash", + }, + { + /* sentinel */ + } +}; + +static struct driver_d litex_spiflash_spi_driver = { + .name = "litex-spiflash", + .probe = litex_spiflash_spi_probe, + .remove = litex_spiflash_spi_remove, + .of_compatible = DRV_OF_COMPAT(litex_spiflash_spi_dt_ids), +}; +device_platform_driver(litex_spiflash_spi_driver); -- 2.32.0 _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox