diff options
Diffstat (limited to 'roms/u-boot/drivers/spi/tegra20_slink.c')
| -rw-r--r-- | roms/u-boot/drivers/spi/tegra20_slink.c | 380 |
1 files changed, 380 insertions, 0 deletions
diff --git a/roms/u-boot/drivers/spi/tegra20_slink.c b/roms/u-boot/drivers/spi/tegra20_slink.c new file mode 100644 index 000000000..209ba8b0c --- /dev/null +++ b/roms/u-boot/drivers/spi/tegra20_slink.c @@ -0,0 +1,380 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * NVIDIA Tegra SPI-SLINK controller + * + * Copyright (c) 2010-2013 NVIDIA Corporation + */ + +#include <common.h> +#include <dm.h> +#include <log.h> +#include <time.h> +#include <asm/global_data.h> +#include <asm/io.h> +#include <asm/arch/clock.h> +#include <asm/arch-tegra/clk_rst.h> +#include <spi.h> +#include <fdtdec.h> +#include <linux/bitops.h> +#include <linux/delay.h> +#include "tegra_spi.h" + +DECLARE_GLOBAL_DATA_PTR; + +/* COMMAND */ +#define SLINK_CMD_ENB BIT(31) +#define SLINK_CMD_GO BIT(30) +#define SLINK_CMD_M_S BIT(28) +#define SLINK_CMD_IDLE_SCLK_DRIVE_LOW (0 << 24) +#define SLINK_CMD_IDLE_SCLK_DRIVE_HIGH BIT(24) +#define SLINK_CMD_IDLE_SCLK_PULL_LOW (2 << 24) +#define SLINK_CMD_IDLE_SCLK_PULL_HIGH (3 << 24) +#define SLINK_CMD_IDLE_SCLK_MASK (3 << 24) +#define SLINK_CMD_CK_SDA BIT(21) +#define SLINK_CMD_CS_POL BIT(13) +#define SLINK_CMD_CS_VAL BIT(12) +#define SLINK_CMD_CS_SOFT BIT(11) +#define SLINK_CMD_BIT_LENGTH BIT(4) +#define SLINK_CMD_BIT_LENGTH_MASK GENMASK(4, 0) +/* COMMAND2 */ +#define SLINK_CMD2_TXEN BIT(30) +#define SLINK_CMD2_RXEN BIT(31) +#define SLINK_CMD2_SS_EN BIT(18) +#define SLINK_CMD2_SS_EN_SHIFT 18 +#define SLINK_CMD2_SS_EN_MASK GENMASK(19, 18) +#define SLINK_CMD2_CS_ACTIVE_BETWEEN BIT(17) +/* STATUS */ +#define SLINK_STAT_BSY BIT(31) +#define SLINK_STAT_RDY BIT(30) +#define SLINK_STAT_ERR BIT(29) +#define SLINK_STAT_RXF_FLUSH BIT(27) +#define SLINK_STAT_TXF_FLUSH BIT(26) +#define SLINK_STAT_RXF_OVF BIT(25) +#define SLINK_STAT_TXF_UNR BIT(24) +#define SLINK_STAT_RXF_EMPTY BIT(23) +#define SLINK_STAT_RXF_FULL BIT(22) +#define SLINK_STAT_TXF_EMPTY BIT(21) +#define SLINK_STAT_TXF_FULL BIT(20) +#define SLINK_STAT_TXF_OVF BIT(19) +#define SLINK_STAT_RXF_UNR BIT(18) +#define SLINK_STAT_CUR_BLKCNT BIT(15) +/* STATUS2 */ +#define SLINK_STAT2_RXF_FULL_CNT BIT(16) +#define SLINK_STAT2_TXF_FULL_CNT BIT(0) + +#define SPI_TIMEOUT 1000 +#define TEGRA_SPI_MAX_FREQ 52000000 + +struct spi_regs { + u32 command; /* SLINK_COMMAND_0 register */ + u32 command2; /* SLINK_COMMAND2_0 reg */ + u32 status; /* SLINK_STATUS_0 register */ + u32 reserved; /* Reserved offset 0C */ + u32 mas_data; /* SLINK_MAS_DATA_0 reg */ + u32 slav_data; /* SLINK_SLAVE_DATA_0 reg */ + u32 dma_ctl; /* SLINK_DMA_CTL_0 register */ + u32 status2; /* SLINK_STATUS2_0 reg */ + u32 rsvd[56]; /* 0x20 to 0xFF reserved */ + u32 tx_fifo; /* SLINK_TX_FIFO_0 reg off 100h */ + u32 rsvd2[31]; /* 0x104 to 0x17F reserved */ + u32 rx_fifo; /* SLINK_RX_FIFO_0 reg off 180h */ +}; + +struct tegra30_spi_priv { + struct spi_regs *regs; + unsigned int freq; + unsigned int mode; + int periph_id; + int valid; + int last_transaction_us; +}; + +struct tegra_spi_slave { + struct spi_slave slave; + struct tegra30_spi_priv *ctrl; +}; + +static int tegra30_spi_of_to_plat(struct udevice *bus) +{ + struct tegra_spi_plat *plat = dev_get_plat(bus); + const void *blob = gd->fdt_blob; + int node = dev_of_offset(bus); + + plat->base = dev_read_addr(bus); + plat->periph_id = clock_decode_periph_id(bus); + + if (plat->periph_id == PERIPH_ID_NONE) { + debug("%s: could not decode periph id %d\n", __func__, + plat->periph_id); + return -FDT_ERR_NOTFOUND; + } + + /* Use 500KHz as a suitable default */ + plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency", + 500000); + plat->deactivate_delay_us = fdtdec_get_int(blob, node, + "spi-deactivate-delay", 0); + debug("%s: base=%#08lx, periph_id=%d, max-frequency=%d, deactivate_delay=%d\n", + __func__, plat->base, plat->periph_id, plat->frequency, + plat->deactivate_delay_us); + + return 0; +} + +static int tegra30_spi_probe(struct udevice *bus) +{ + struct tegra_spi_plat *plat = dev_get_plat(bus); + struct tegra30_spi_priv *priv = dev_get_priv(bus); + + priv->regs = (struct spi_regs *)plat->base; + + priv->last_transaction_us = timer_get_us(); + priv->freq = plat->frequency; + priv->periph_id = plat->periph_id; + + /* Change SPI clock to correct frequency, PLLP_OUT0 source */ + clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH, + priv->freq); + + return 0; +} + +static int tegra30_spi_claim_bus(struct udevice *dev) +{ + struct udevice *bus = dev->parent; + struct tegra30_spi_priv *priv = dev_get_priv(bus); + struct spi_regs *regs = priv->regs; + u32 reg; + + /* Change SPI clock to correct frequency, PLLP_OUT0 source */ + clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH, + priv->freq); + + /* Clear stale status here */ + reg = SLINK_STAT_RDY | SLINK_STAT_RXF_FLUSH | SLINK_STAT_TXF_FLUSH | \ + SLINK_STAT_RXF_UNR | SLINK_STAT_TXF_OVF; + writel(reg, ®s->status); + debug("%s: STATUS = %08x\n", __func__, readl(®s->status)); + + /* Set master mode and sw controlled CS */ + reg = readl(®s->command); + reg |= SLINK_CMD_M_S | SLINK_CMD_CS_SOFT; + writel(reg, ®s->command); + debug("%s: COMMAND = %08x\n", __func__, readl(®s->command)); + + return 0; +} + +static void spi_cs_activate(struct udevice *dev) +{ + struct udevice *bus = dev->parent; + struct tegra_spi_plat *pdata = dev_get_plat(bus); + struct tegra30_spi_priv *priv = dev_get_priv(bus); + + /* If it's too soon to do another transaction, wait */ + if (pdata->deactivate_delay_us && + priv->last_transaction_us) { + ulong delay_us; /* The delay completed so far */ + delay_us = timer_get_us() - priv->last_transaction_us; + if (delay_us < pdata->deactivate_delay_us) + udelay(pdata->deactivate_delay_us - delay_us); + } + + /* CS is negated on Tegra, so drive a 1 to get a 0 */ + setbits_le32(&priv->regs->command, SLINK_CMD_CS_VAL); +} + +static void spi_cs_deactivate(struct udevice *dev) +{ + struct udevice *bus = dev->parent; + struct tegra_spi_plat *pdata = dev_get_plat(bus); + struct tegra30_spi_priv *priv = dev_get_priv(bus); + + /* CS is negated on Tegra, so drive a 0 to get a 1 */ + clrbits_le32(&priv->regs->command, SLINK_CMD_CS_VAL); + + /* Remember time of this transaction so we can honour the bus delay */ + if (pdata->deactivate_delay_us) + priv->last_transaction_us = timer_get_us(); +} + +static int tegra30_spi_xfer(struct udevice *dev, unsigned int bitlen, + const void *data_out, void *data_in, + unsigned long flags) +{ + struct udevice *bus = dev->parent; + struct tegra30_spi_priv *priv = dev_get_priv(bus); + struct spi_regs *regs = priv->regs; + u32 reg, tmpdout, tmpdin = 0; + const u8 *dout = data_out; + u8 *din = data_in; + int num_bytes; + int ret; + + debug("%s: slave %u:%u dout %p din %p bitlen %u\n", + __func__, dev_seq(bus), spi_chip_select(dev), dout, din, bitlen); + if (bitlen % 8) + return -1; + num_bytes = bitlen / 8; + + ret = 0; + + reg = readl(®s->status); + writel(reg, ®s->status); /* Clear all SPI events via R/W */ + debug("%s entry: STATUS = %08x\n", __func__, reg); + + reg = readl(®s->status2); + writel(reg, ®s->status2); /* Clear all STATUS2 events via R/W */ + debug("%s entry: STATUS2 = %08x\n", __func__, reg); + + debug("%s entry: COMMAND = %08x\n", __func__, readl(®s->command)); + + clrsetbits_le32(®s->command2, SLINK_CMD2_SS_EN_MASK, + SLINK_CMD2_TXEN | SLINK_CMD2_RXEN | + (spi_chip_select(dev) << SLINK_CMD2_SS_EN_SHIFT)); + debug("%s entry: COMMAND2 = %08x\n", __func__, readl(®s->command2)); + + if (flags & SPI_XFER_BEGIN) + spi_cs_activate(dev); + + /* handle data in 32-bit chunks */ + while (num_bytes > 0) { + int bytes; + int is_read = 0; + int tm, i; + + tmpdout = 0; + bytes = (num_bytes > 4) ? 4 : num_bytes; + + if (dout != NULL) { + for (i = 0; i < bytes; ++i) + tmpdout = (tmpdout << 8) | dout[i]; + dout += bytes; + } + + num_bytes -= bytes; + + clrsetbits_le32(®s->command, SLINK_CMD_BIT_LENGTH_MASK, + bytes * 8 - 1); + writel(tmpdout, ®s->tx_fifo); + setbits_le32(®s->command, SLINK_CMD_GO); + + /* + * Wait for SPI transmit FIFO to empty, or to time out. + * The RX FIFO status will be read and cleared last + */ + for (tm = 0, is_read = 0; tm < SPI_TIMEOUT; ++tm) { + u32 status; + + status = readl(®s->status); + + /* We can exit when we've had both RX and TX activity */ + if (is_read && (status & SLINK_STAT_TXF_EMPTY)) + break; + + if ((status & (SLINK_STAT_BSY | SLINK_STAT_RDY)) != + SLINK_STAT_RDY) + tm++; + + else if (!(status & SLINK_STAT_RXF_EMPTY)) { + tmpdin = readl(®s->rx_fifo); + is_read = 1; + + /* swap bytes read in */ + if (din != NULL) { + for (i = bytes - 1; i >= 0; --i) { + din[i] = tmpdin & 0xff; + tmpdin >>= 8; + } + din += bytes; + } + } + } + + if (tm >= SPI_TIMEOUT) + ret = tm; + + /* clear ACK RDY, etc. bits */ + writel(readl(®s->status), ®s->status); + } + + if (flags & SPI_XFER_END) + spi_cs_deactivate(dev); + + debug("%s: transfer ended. Value=%08x, status = %08x\n", + __func__, tmpdin, readl(®s->status)); + + if (ret) { + printf("%s: timeout during SPI transfer, tm %d\n", + __func__, ret); + return -1; + } + + return 0; +} + +static int tegra30_spi_set_speed(struct udevice *bus, uint speed) +{ + struct tegra_spi_plat *plat = dev_get_plat(bus); + struct tegra30_spi_priv *priv = dev_get_priv(bus); + + if (speed > plat->frequency) + speed = plat->frequency; + priv->freq = speed; + debug("%s: regs=%p, speed=%d\n", __func__, priv->regs, priv->freq); + + return 0; +} + +static int tegra30_spi_set_mode(struct udevice *bus, uint mode) +{ + struct tegra30_spi_priv *priv = dev_get_priv(bus); + struct spi_regs *regs = priv->regs; + u32 reg; + + reg = readl(®s->command); + + /* Set CPOL and CPHA */ + reg &= ~(SLINK_CMD_IDLE_SCLK_MASK | SLINK_CMD_CK_SDA); + if (mode & SPI_CPHA) + reg |= SLINK_CMD_CK_SDA; + + if (mode & SPI_CPOL) + reg |= SLINK_CMD_IDLE_SCLK_DRIVE_HIGH; + else + reg |= SLINK_CMD_IDLE_SCLK_DRIVE_LOW; + + writel(reg, ®s->command); + + priv->mode = mode; + debug("%s: regs=%p, mode=%d\n", __func__, priv->regs, priv->mode); + + return 0; +} + +static const struct dm_spi_ops tegra30_spi_ops = { + .claim_bus = tegra30_spi_claim_bus, + .xfer = tegra30_spi_xfer, + .set_speed = tegra30_spi_set_speed, + .set_mode = tegra30_spi_set_mode, + /* + * cs_info is not needed, since we require all chip selects to be + * in the device tree explicitly + */ +}; + +static const struct udevice_id tegra30_spi_ids[] = { + { .compatible = "nvidia,tegra20-slink" }, + { } +}; + +U_BOOT_DRIVER(tegra30_spi) = { + .name = "tegra20_slink", + .id = UCLASS_SPI, + .of_match = tegra30_spi_ids, + .ops = &tegra30_spi_ops, + .of_to_plat = tegra30_spi_of_to_plat, + .plat_auto = sizeof(struct tegra_spi_plat), + .priv_auto = sizeof(struct tegra30_spi_priv), + .probe = tegra30_spi_probe, +}; |