diff options
Diffstat (limited to 'drivers/spi/tegra114_spi.c')
| -rw-r--r-- | drivers/spi/tegra114_spi.c | 405 |
1 files changed, 405 insertions, 0 deletions
diff --git a/drivers/spi/tegra114_spi.c b/drivers/spi/tegra114_spi.c new file mode 100644 index 0000000..b11a0a1 --- /dev/null +++ b/drivers/spi/tegra114_spi.c @@ -0,0 +1,405 @@ +/* + * NVIDIA Tegra SPI controller (T114 and later) + * + * Copyright (c) 2010-2013 NVIDIA Corporation + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * 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., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> +#include <malloc.h> +#include <asm/io.h> +#include <asm/gpio.h> +#include <asm/arch/clock.h> +#include <asm/arch-tegra/clk_rst.h> +#include <asm/arch-tegra114/tegra114_spi.h> +#include <spi.h> +#include <fdtdec.h> + +DECLARE_GLOBAL_DATA_PTR; + +/* COMMAND1 */ +#define SPI_CMD1_GO (1 << 31) +#define SPI_CMD1_M_S (1 << 30) +#define SPI_CMD1_MODE_MASK 0x3 +#define SPI_CMD1_MODE_SHIFT 28 +#define SPI_CMD1_CS_SEL_MASK 0x3 +#define SPI_CMD1_CS_SEL_SHIFT 26 +#define SPI_CMD1_CS_POL_INACTIVE3 (1 << 25) +#define SPI_CMD1_CS_POL_INACTIVE2 (1 << 24) +#define SPI_CMD1_CS_POL_INACTIVE1 (1 << 23) +#define SPI_CMD1_CS_POL_INACTIVE0 (1 << 22) +#define SPI_CMD1_CS_SW_HW (1 << 21) +#define SPI_CMD1_CS_SW_VAL (1 << 20) +#define SPI_CMD1_IDLE_SDA_MASK 0x3 +#define SPI_CMD1_IDLE_SDA_SHIFT 18 +#define SPI_CMD1_BIDIR (1 << 17) +#define SPI_CMD1_LSBI_FE (1 << 16) +#define SPI_CMD1_LSBY_FE (1 << 15) +#define SPI_CMD1_BOTH_EN_BIT (1 << 14) +#define SPI_CMD1_BOTH_EN_BYTE (1 << 13) +#define SPI_CMD1_RX_EN (1 << 12) +#define SPI_CMD1_TX_EN (1 << 11) +#define SPI_CMD1_PACKED (1 << 5) +#define SPI_CMD1_BIT_LEN_MASK 0x1F +#define SPI_CMD1_BIT_LEN_SHIFT 0 + +/* COMMAND2 */ +#define SPI_CMD2_TX_CLK_TAP_DELAY (1 << 6) +#define SPI_CMD2_TX_CLK_TAP_DELAY_MASK (0x3F << 6) +#define SPI_CMD2_RX_CLK_TAP_DELAY (1 << 0) +#define SPI_CMD2_RX_CLK_TAP_DELAY_MASK (0x3F << 0) + +/* TRANSFER STATUS */ +#define SPI_XFER_STS_RDY (1 << 30) + +/* FIFO STATUS */ +#define SPI_FIFO_STS_CS_INACTIVE (1 << 31) +#define SPI_FIFO_STS_FRAME_END (1 << 30) +#define SPI_FIFO_STS_RX_FIFO_FLUSH (1 << 15) +#define SPI_FIFO_STS_TX_FIFO_FLUSH (1 << 14) +#define SPI_FIFO_STS_ERR (1 << 8) +#define SPI_FIFO_STS_TX_FIFO_OVF (1 << 7) +#define SPI_FIFO_STS_TX_FIFO_UNR (1 << 6) +#define SPI_FIFO_STS_RX_FIFO_OVF (1 << 5) +#define SPI_FIFO_STS_RX_FIFO_UNR (1 << 4) +#define SPI_FIFO_STS_TX_FIFO_FULL (1 << 3) +#define SPI_FIFO_STS_TX_FIFO_EMPTY (1 << 2) +#define SPI_FIFO_STS_RX_FIFO_FULL (1 << 1) +#define SPI_FIFO_STS_RX_FIFO_EMPTY (1 << 0) + +#define SPI_TIMEOUT 1000 +#define TEGRA_SPI_MAX_FREQ 52000000 + +struct spi_regs { + u32 command1; /* 000:SPI_COMMAND1 register */ + u32 command2; /* 004:SPI_COMMAND2 register */ + u32 timing1; /* 008:SPI_CS_TIM1 register */ + u32 timing2; /* 00c:SPI_CS_TIM2 register */ + u32 xfer_status;/* 010:SPI_TRANS_STATUS register */ + u32 fifo_status;/* 014:SPI_FIFO_STATUS register */ + u32 tx_data; /* 018:SPI_TX_DATA register */ + u32 rx_data; /* 01c:SPI_RX_DATA register */ + u32 dma_ctl; /* 020:SPI_DMA_CTL register */ + u32 dma_blk; /* 024:SPI_DMA_BLK register */ + u32 rsvd[56]; /* 028-107 reserved */ + u32 tx_fifo; /* 108:SPI_FIFO1 register */ + u32 rsvd2[31]; /* 10c-187 reserved */ + u32 rx_fifo; /* 188:SPI_FIFO2 register */ + u32 spare_ctl; /* 18c:SPI_SPARE_CTRL register */ +}; + +struct tegra_spi_ctrl { + struct spi_regs *regs; + unsigned int freq; + unsigned int mode; + int periph_id; + int valid; +}; + +struct tegra_spi_slave { + struct spi_slave slave; + struct tegra_spi_ctrl *ctrl; +}; + +static struct tegra_spi_ctrl spi_ctrls[CONFIG_TEGRA114_SPI_CTRLS]; + +static inline struct tegra_spi_slave *to_tegra_spi(struct spi_slave *slave) +{ + return container_of(slave, struct tegra_spi_slave, slave); +} + +int tegra114_spi_cs_is_valid(unsigned int bus, unsigned int cs) +{ + if (bus >= CONFIG_TEGRA114_SPI_CTRLS || cs > 3 || !spi_ctrls[bus].valid) + return 0; + else + return 1; +} + +struct spi_slave *tegra114_spi_setup_slave(unsigned int bus, unsigned int cs, + unsigned int max_hz, unsigned int mode) +{ + struct tegra_spi_slave *spi; + + debug("%s: bus: %u, cs: %u, max_hz: %u, mode: %u\n", __func__, + bus, cs, max_hz, mode); + + if (!spi_cs_is_valid(bus, cs)) { + printf("SPI error: unsupported bus %d / chip select %d\n", + bus, cs); + return NULL; + } + + if (max_hz > TEGRA_SPI_MAX_FREQ) { + printf("SPI error: unsupported frequency %d Hz. Max frequency" + " is %d Hz\n", max_hz, TEGRA_SPI_MAX_FREQ); + return NULL; + } + + spi = malloc(sizeof(struct tegra_spi_slave)); + if (!spi) { + printf("SPI error: malloc of SPI structure failed\n"); + return NULL; + } + spi->slave.bus = bus; + spi->slave.cs = cs; + spi->ctrl = &spi_ctrls[bus]; + if (!spi->ctrl) { + printf("SPI error: could not find controller for bus %d\n", + bus); + return NULL; + } + + if (max_hz < spi->ctrl->freq) { + debug("%s: limiting frequency from %u to %u\n", __func__, + spi->ctrl->freq, max_hz); + spi->ctrl->freq = max_hz; + } + spi->ctrl->mode = mode; + + return &spi->slave; +} + +void tegra114_spi_free_slave(struct spi_slave *slave) +{ + struct tegra_spi_slave *spi = to_tegra_spi(slave); + + free(spi); +} + +int tegra114_spi_init(int *node_list, int count) +{ + struct tegra_spi_ctrl *ctrl; + int i; + int node = 0; + int found = 0; + + for (i = 0; i < count; i++) { + ctrl = &spi_ctrls[i]; + node = node_list[i]; + + ctrl->regs = (struct spi_regs *)fdtdec_get_addr(gd->fdt_blob, + node, "reg"); + if ((fdt_addr_t)ctrl->regs == FDT_ADDR_T_NONE) { + debug("%s: no spi register found\n", __func__); + continue; + } + ctrl->freq = fdtdec_get_int(gd->fdt_blob, node, + "spi-max-frequency", 0); + if (!ctrl->freq) { + debug("%s: no spi max frequency found\n", __func__); + continue; + } + + ctrl->periph_id = clock_decode_periph_id(gd->fdt_blob, node); + if (ctrl->periph_id == PERIPH_ID_NONE) { + debug("%s: could not decode periph id\n", __func__); + continue; + } + ctrl->valid = 1; + found = 1; + + debug("%s: found controller at %p, freq = %u, periph_id = %d\n", + __func__, ctrl->regs, ctrl->freq, ctrl->periph_id); + } + + return !found; +} + +int tegra114_spi_claim_bus(struct spi_slave *slave) +{ + struct tegra_spi_slave *spi = to_tegra_spi(slave); + struct spi_regs *regs = spi->ctrl->regs; + + /* Change SPI clock to correct frequency, PLLP_OUT0 source */ + clock_start_periph_pll(spi->ctrl->periph_id, CLOCK_ID_PERIPH, + spi->ctrl->freq); + + /* Clear stale status here */ + setbits_le32(®s->fifo_status, + SPI_FIFO_STS_ERR | + SPI_FIFO_STS_TX_FIFO_OVF | + SPI_FIFO_STS_TX_FIFO_UNR | + SPI_FIFO_STS_RX_FIFO_OVF | + SPI_FIFO_STS_RX_FIFO_UNR | + SPI_FIFO_STS_TX_FIFO_FULL | + SPI_FIFO_STS_TX_FIFO_EMPTY | + SPI_FIFO_STS_RX_FIFO_FULL | + SPI_FIFO_STS_RX_FIFO_EMPTY); + debug("%s: FIFO STATUS = %08x\n", __func__, readl(®s->fifo_status)); + + /* Set master mode and sw controlled CS */ + setbits_le32(®s->command1, SPI_CMD1_M_S | SPI_CMD1_CS_SW_HW | + (spi->ctrl->mode << SPI_CMD1_MODE_SHIFT)); + debug("%s: COMMAND1 = %08x\n", __func__, readl(®s->command1)); + + return 0; +} + +void tegra114_spi_cs_activate(struct spi_slave *slave) +{ + struct tegra_spi_slave *spi = to_tegra_spi(slave); + struct spi_regs *regs = spi->ctrl->regs; + + clrbits_le32(®s->command1, SPI_CMD1_CS_SW_VAL); +} + +void tegra114_spi_cs_deactivate(struct spi_slave *slave) +{ + struct tegra_spi_slave *spi = to_tegra_spi(slave); + struct spi_regs *regs = spi->ctrl->regs; + + setbits_le32(®s->command1, SPI_CMD1_CS_SW_VAL); +} + +int tegra114_spi_xfer(struct spi_slave *slave, unsigned int bitlen, + const void *data_out, void *data_in, unsigned long flags) +{ + struct tegra_spi_slave *spi = to_tegra_spi(slave); + struct spi_regs *regs = spi->ctrl->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__, slave->bus, slave->cs, dout, din, bitlen); + if (bitlen % 8) + return -1; + num_bytes = bitlen / 8; + + ret = 0; + + /* clear all error status bits */ + reg = readl(®s->fifo_status); + writel(reg, ®s->fifo_status); + + /* clear ready bit */ + setbits_le32(®s->xfer_status, SPI_XFER_STS_RDY); + + clrsetbits_le32(®s->command1, SPI_CMD1_CS_SW_VAL, + SPI_CMD1_RX_EN | SPI_CMD1_TX_EN | SPI_CMD1_LSBY_FE | + (slave->cs << SPI_CMD1_CS_SEL_SHIFT)); + + /* set xfer size to 1 block (32 bits) */ + writel(0, ®s->dma_blk); + + if (flags & SPI_XFER_BEGIN) + spi_cs_activate(slave); + + /* 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->command1, + SPI_CMD1_BIT_LEN_MASK << SPI_CMD1_BIT_LEN_SHIFT, + (bytes * 8 - 1) << SPI_CMD1_BIT_LEN_SHIFT); + writel(tmpdout, ®s->tx_fifo); + setbits_le32(®s->command1, SPI_CMD1_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 fifo_status, xfer_status; + + fifo_status = readl(®s->fifo_status); + + /* We can exit when we've had both RX and TX activity */ + if (is_read && + (fifo_status & SPI_FIFO_STS_TX_FIFO_EMPTY)) + break; + + xfer_status = readl(®s->xfer_status); + if (!(xfer_status & SPI_XFER_STS_RDY)) + continue; + + if (fifo_status & SPI_FIFO_STS_ERR) { + debug("%s: got a fifo error: ", __func__); + if (fifo_status & SPI_FIFO_STS_TX_FIFO_OVF) + debug("tx FIFO overflow "); + if (fifo_status & SPI_FIFO_STS_TX_FIFO_UNR) + debug("tx FIFO underrun "); + if (fifo_status & SPI_FIFO_STS_RX_FIFO_OVF) + debug("rx FIFO overflow "); + if (fifo_status & SPI_FIFO_STS_RX_FIFO_UNR) + debug("rx FIFO underrun "); + if (fifo_status & SPI_FIFO_STS_TX_FIFO_FULL) + debug("tx FIFO full "); + if (fifo_status & SPI_FIFO_STS_TX_FIFO_EMPTY) + debug("tx FIFO empty "); + if (fifo_status & SPI_FIFO_STS_RX_FIFO_FULL) + debug("rx FIFO full "); + if (fifo_status & SPI_FIFO_STS_RX_FIFO_EMPTY) + debug("rx FIFO empty "); + debug("\n"); + break; + } + + if (!(fifo_status & SPI_FIFO_STS_RX_FIFO_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->fifo_status), ®s->fifo_status); + } + + if (flags & SPI_XFER_END) + spi_cs_deactivate(slave); + + debug("%s: transfer ended. Value=%08x, fifo_status = %08x\n", + __func__, tmpdin, readl(®s->fifo_status)); + + if (ret) { + printf("%s: timeout during SPI transfer, tm %d\n", + __func__, ret); + return -1; + } + + return 0; +} |