diff options
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/spi/atmel_spi.c | 288 |
2 files changed, 296 insertions, 0 deletions
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 8724f87c49..0f51b3a21b 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -32,6 +32,14 @@ config ATH79_SPI uses driver model and requires a device tree binding to operate. please refer to doc/device-tree-bindings/spi/spi-ath79.txt. +config ATMEL_SPI + bool "Atmel SPI driver" + depends on ARCH_AT91 + help + This enables driver for the Atmel SPI Controller, present on + many AT32 (AVR32) and AT91 (ARM) chips. This driver can be + used to access the SPI Flash, such as AT25DF321. + config CADENCE_QSPI bool "Cadence QSPI driver" help diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c index ed6278b86f..7649114231 100644 --- a/drivers/spi/atmel_spi.c +++ b/drivers/spi/atmel_spi.c @@ -4,16 +4,30 @@ * SPDX-License-Identifier: GPL-2.0+ */ #include <common.h> +#include <clk.h> +#include <dm.h> +#include <fdtdec.h> #include <spi.h> #include <malloc.h> +#include <wait_bit.h> #include <asm/io.h> #include <asm/arch/clk.h> #include <asm/arch/hardware.h> +#ifdef CONFIG_DM_SPI +#include <asm/arch/at91_spi.h> +#endif +#ifdef CONFIG_DM_GPIO +#include <asm/gpio.h> +#endif #include "atmel_spi.h" +DECLARE_GLOBAL_DATA_PTR; + +#ifndef CONFIG_DM_SPI + static int spi_has_wdrbt(struct atmel_spi_slave *slave) { unsigned int ver; @@ -209,3 +223,277 @@ out: return 0; } + +#else + +#define MAX_CS_COUNT 4 + +struct atmel_spi_platdata { + struct at91_spi *regs; +}; + +struct atmel_spi_priv { + unsigned int freq; /* Default frequency */ + unsigned int mode; + ulong bus_clk_rate; + struct gpio_desc cs_gpios[MAX_CS_COUNT]; +}; + +static int atmel_spi_claim_bus(struct udevice *dev) +{ + struct udevice *bus = dev_get_parent(dev); + struct atmel_spi_platdata *bus_plat = dev_get_platdata(bus); + struct atmel_spi_priv *priv = dev_get_priv(bus); + struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev); + struct at91_spi *reg_base = bus_plat->regs; + u32 cs = slave_plat->cs; + u32 freq = priv->freq; + u32 scbr, csrx, mode; + + scbr = (priv->bus_clk_rate + freq - 1) / freq; + if (scbr > ATMEL_SPI_CSRx_SCBR_MAX) + return -EINVAL; + + if (scbr < 1) + scbr = 1; + + csrx = ATMEL_SPI_CSRx_SCBR(scbr); + csrx |= ATMEL_SPI_CSRx_BITS(ATMEL_SPI_BITS_8); + + if (!(priv->mode & SPI_CPHA)) + csrx |= ATMEL_SPI_CSRx_NCPHA; + if (priv->mode & SPI_CPOL) + csrx |= ATMEL_SPI_CSRx_CPOL; + + writel(csrx, ®_base->csr[cs]); + + mode = ATMEL_SPI_MR_MSTR | + ATMEL_SPI_MR_MODFDIS | + ATMEL_SPI_MR_WDRBT | + ATMEL_SPI_MR_PCS(~(1 << cs)); + + writel(mode, ®_base->mr); + + writel(ATMEL_SPI_CR_SPIEN, ®_base->cr); + + return 0; +} + +static int atmel_spi_release_bus(struct udevice *dev) +{ + struct udevice *bus = dev_get_parent(dev); + struct atmel_spi_platdata *bus_plat = dev_get_platdata(bus); + + writel(ATMEL_SPI_CR_SPIDIS, &bus_plat->regs->cr); + + return 0; +} + +static void atmel_spi_cs_activate(struct udevice *dev) +{ + struct udevice *bus = dev_get_parent(dev); + struct atmel_spi_priv *priv = dev_get_priv(bus); + struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev); + u32 cs = slave_plat->cs; + + dm_gpio_set_value(&priv->cs_gpios[cs], 0); +} + +static void atmel_spi_cs_deactivate(struct udevice *dev) +{ + struct udevice *bus = dev_get_parent(dev); + struct atmel_spi_priv *priv = dev_get_priv(bus); + struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev); + u32 cs = slave_plat->cs; + + dm_gpio_set_value(&priv->cs_gpios[cs], 1); +} + +static int atmel_spi_xfer(struct udevice *dev, unsigned int bitlen, + const void *dout, void *din, unsigned long flags) +{ + struct udevice *bus = dev_get_parent(dev); + struct atmel_spi_platdata *bus_plat = dev_get_platdata(bus); + struct at91_spi *reg_base = bus_plat->regs; + + u32 len_tx, len_rx, len; + u32 status; + const u8 *txp = dout; + u8 *rxp = din; + u8 value; + + if (bitlen == 0) + goto out; + + /* + * The controller can do non-multiple-of-8 bit + * transfers, but this driver currently doesn't support it. + * + * It's also not clear how such transfers are supposed to be + * represented as a stream of bytes...this is a limitation of + * the current SPI interface. + */ + if (bitlen % 8) { + /* Errors always terminate an ongoing transfer */ + flags |= SPI_XFER_END; + goto out; + } + + len = bitlen / 8; + + /* + * The controller can do automatic CS control, but it is + * somewhat quirky, and it doesn't really buy us much anyway + * in the context of U-Boot. + */ + if (flags & SPI_XFER_BEGIN) { + atmel_spi_cs_activate(dev); + + /* + * sometimes the RDR is not empty when we get here, + * in theory that should not happen, but it DOES happen. + * Read it here to be on the safe side. + * That also clears the OVRES flag. Required if the + * following loop exits due to OVRES! + */ + readl(®_base->rdr); + } + + for (len_tx = 0, len_rx = 0; len_rx < len; ) { + status = readl(®_base->sr); + + if (status & ATMEL_SPI_SR_OVRES) + return -1; + + if ((len_tx < len) && (status & ATMEL_SPI_SR_TDRE)) { + if (txp) + value = *txp++; + else + value = 0; + writel(value, ®_base->tdr); + len_tx++; + } + + if (status & ATMEL_SPI_SR_RDRF) { + value = readl(®_base->rdr); + if (rxp) + *rxp++ = value; + len_rx++; + } + } + +out: + if (flags & SPI_XFER_END) { + /* + * Wait until the transfer is completely done before + * we deactivate CS. + */ + wait_for_bit(__func__, ®_base->sr, + ATMEL_SPI_SR_TXEMPTY, true, 1000, false); + + atmel_spi_cs_deactivate(dev); + } + + return 0; +} + +static int atmel_spi_set_speed(struct udevice *bus, uint speed) +{ + struct atmel_spi_priv *priv = dev_get_priv(bus); + + priv->freq = speed; + + return 0; +} + +static int atmel_spi_set_mode(struct udevice *bus, uint mode) +{ + struct atmel_spi_priv *priv = dev_get_priv(bus); + + priv->mode = mode; + + return 0; +} + +static const struct dm_spi_ops atmel_spi_ops = { + .claim_bus = atmel_spi_claim_bus, + .release_bus = atmel_spi_release_bus, + .xfer = atmel_spi_xfer, + .set_speed = atmel_spi_set_speed, + .set_mode = atmel_spi_set_mode, + /* + * cs_info is not needed, since we require all chip selects to be + * in the device tree explicitly + */ +}; + +static int atmel_spi_enable_clk(struct udevice *bus) +{ + struct atmel_spi_priv *priv = dev_get_priv(bus); + struct clk clk; + ulong clk_rate; + int ret; + + ret = clk_get_by_index(bus, 0, &clk); + if (ret) + return -EINVAL; + + ret = clk_enable(&clk); + if (ret) + return ret; + + clk_rate = clk_get_rate(&clk); + if (!clk_rate) + return -EINVAL; + + priv->bus_clk_rate = clk_rate; + + clk_free(&clk); + + return 0; +} + +static int atmel_spi_probe(struct udevice *bus) +{ + struct atmel_spi_platdata *bus_plat = dev_get_platdata(bus); + struct atmel_spi_priv *priv = dev_get_priv(bus); + int i, ret; + + ret = atmel_spi_enable_clk(bus); + if (ret) + return ret; + + bus_plat->regs = (struct at91_spi *)dev_get_addr(bus); + + ret = gpio_request_list_by_name(bus, "cs-gpios", priv->cs_gpios, + ARRAY_SIZE(priv->cs_gpios), 0); + if (ret < 0) { + error("Can't get %s gpios! Error: %d", bus->name, ret); + return ret; + } + + for(i = 0; i < ARRAY_SIZE(priv->cs_gpios); i++) { + dm_gpio_set_dir_flags(&priv->cs_gpios[i], + GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE); + } + + writel(ATMEL_SPI_CR_SWRST, &bus_plat->regs->cr); + + return 0; +} + +static const struct udevice_id atmel_spi_ids[] = { + { .compatible = "atmel,at91rm9200-spi" }, + { } +}; + +U_BOOT_DRIVER(atmel_spi) = { + .name = "atmel_spi", + .id = UCLASS_SPI, + .of_match = atmel_spi_ids, + .ops = &atmel_spi_ops, + .platdata_auto_alloc_size = sizeof(struct atmel_spi_platdata), + .priv_auto_alloc_size = sizeof(struct atmel_spi_priv), + .probe = atmel_spi_probe, +}; +#endif |