[U-Boot] [PATCH v2 3/8] tegra2: spi: Add SPI driver for Tegra2 SOC
Simon Glass
sjg at chromium.org
Thu Nov 3 23:41:34 CET 2011
From: Tom Warren <twarren.nvidia at gmail.com>
This driver supports SPI on Tegra2, running at 48MHz.
Signed-off-by: Tom Warren <twarren at nvidia.com>
---
Changes in v2:
- Update to support SPI mode and frequency
- Tidy driver according to comments, and tidy a little more
arch/arm/include/asm/arch-tegra2/tegra2.h | 1 +
arch/arm/include/asm/arch-tegra2/tegra2_spi.h | 76 +++++++
board/nvidia/common/board.c | 4 +
drivers/spi/Makefile | 1 +
drivers/spi/tegra2_spi.c | 276 +++++++++++++++++++++++++
5 files changed, 358 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/include/asm/arch-tegra2/tegra2_spi.h
create mode 100644 drivers/spi/tegra2_spi.c
diff --git a/arch/arm/include/asm/arch-tegra2/tegra2.h b/arch/arm/include/asm/arch-tegra2/tegra2.h
index 742a75a..8941443 100644
--- a/arch/arm/include/asm/arch-tegra2/tegra2.h
+++ b/arch/arm/include/asm/arch-tegra2/tegra2.h
@@ -38,6 +38,7 @@
#define NV_PA_APB_UARTC_BASE (NV_PA_APB_MISC_BASE + 0x6200)
#define NV_PA_APB_UARTD_BASE (NV_PA_APB_MISC_BASE + 0x6300)
#define NV_PA_APB_UARTE_BASE (NV_PA_APB_MISC_BASE + 0x6400)
+#define TEGRA2_SPI_BASE (NV_PA_APB_MISC_BASE + 0xC380)
#define NV_PA_PMC_BASE 0x7000E400
#define NV_PA_CSITE_BASE 0x70040000
diff --git a/arch/arm/include/asm/arch-tegra2/tegra2_spi.h b/arch/arm/include/asm/arch-tegra2/tegra2_spi.h
new file mode 100644
index 0000000..ceec428
--- /dev/null
+++ b/arch/arm/include/asm/arch-tegra2/tegra2_spi.h
@@ -0,0 +1,76 @@
+/*
+ * NVIDIA Tegra2 SPI-FLASH controller
+ *
+ * Copyright 2010-2011 NVIDIA Corporation
+ *
+ * This software may be used and distributed according to the
+ * terms of the GNU Public License, Version 2, incorporated
+ * herein by reference.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * Version 2 as published by the Free Software Foundation.
+ *
+ * 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
+ */
+
+#ifndef _TEGRA2_SPI_H_
+#define _TEGRA2_SPI_H_
+
+#include <asm/types.h>
+
+struct spi_tegra {
+ u32 command; /* SPI_COMMAND_0 register */
+ u32 status; /* SPI_STATUS_0 register */
+ u32 rx_cmp; /* SPI_RX_CMP_0 register */
+ u32 dma_ctl; /* SPI_DMA_CTL_0 register */
+ u32 tx_fifo; /* SPI_TX_FIFO_0 register */
+ u32 rsvd[3]; /* offsets 0x14 to 0x1F reserved */
+ u32 rx_fifo; /* SPI_RX_FIFO_0 register */
+};
+
+#define SPI_CMD_GO (1 << 30)
+#define SPI_CMD_ACTIVE_SCLK_SHIFT 26
+#define SPI_CMD_ACTIVE_SCLK_MASK (3 << SPI_CMD_ACTIVE_SCLK_SHIFT)
+#define SPI_CMD_CK_SDA (1 << 21)
+#define SPI_CMD_ACTIVE_SDA_SHIFT 18
+#define SPI_CMD_ACTIVE_SDA_MASK (3 << SPI_CMD_ACTIVE_SDA_SHIFT)
+#define SPI_CMD_CS_POL (1 << 16)
+#define SPI_CMD_TXEN (1 << 15)
+#define SPI_CMD_RXEN (1 << 14)
+#define SPI_CMD_CS_VAL (1 << 13)
+#define SPI_CMD_CS_SOFT (1 << 12)
+#define SPI_CMD_CS_DELAY (1 << 9)
+#define SPI_CMD_CS3_EN (1 << 8)
+#define SPI_CMD_CS2_EN (1 << 7)
+#define SPI_CMD_CS1_EN (1 << 6)
+#define SPI_CMD_CS0_EN (1 << 5)
+#define SPI_CMD_BIT_LENGTH (1 << 4)
+#define SPI_CMD_BIT_LENGTH_MASK 0x0000001F
+
+#define SPI_STAT_BSY (1 << 31)
+#define SPI_STAT_RDY (1 << 30)
+#define SPI_STAT_RXF_FLUSH (1 << 29)
+#define SPI_STAT_TXF_FLUSH (1 << 28)
+#define SPI_STAT_RXF_UNR (1 << 27)
+#define SPI_STAT_TXF_OVF (1 << 26)
+#define SPI_STAT_RXF_EMPTY (1 << 25)
+#define SPI_STAT_RXF_FULL (1 << 24)
+#define SPI_STAT_TXF_EMPTY (1 << 23)
+#define SPI_STAT_TXF_FULL (1 << 22)
+#define SPI_STAT_SEL_TXRX_N (1 << 16)
+#define SPI_STAT_CUR_BLKCNT (1 << 15)
+
+#define SPI_TIMEOUT 1000
+#define TEGRA2_SPI_MAX_FREQ 52000000
+
+
+#endif /* _TEGRA2_SPI_H_ */
diff --git a/board/nvidia/common/board.c b/board/nvidia/common/board.c
index a2d45c1..2591ebc 100644
--- a/board/nvidia/common/board.c
+++ b/board/nvidia/common/board.c
@@ -31,6 +31,7 @@
#include <asm/arch/clock.h>
#include <asm/arch/pinmux.h>
#include <asm/arch/uart.h>
+#include <spi.h>
#include "board.h"
DECLARE_GLOBAL_DATA_PTR;
@@ -114,6 +115,9 @@ int board_init(void)
clock_init();
clock_verify();
+#ifdef CONFIG_TEGRA2_SPI
+ spi_init();
+#endif
/* boot param addr */
gd->bd->bi_boot_params = (NV_PA_SDRAM_BASE + 0x100);
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 84ad6fa..0a06822 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -42,6 +42,7 @@ COBJS-$(CONFIG_OMAP3_SPI) += omap3_spi.o
COBJS-$(CONFIG_SOFT_SPI) += soft_spi.o
COBJS-$(CONFIG_SH_SPI) += sh_spi.o
COBJS-$(CONFIG_FSL_ESPI) += fsl_espi.o
+COBJS-$(CONFIG_TEGRA2_SPI) += tegra2_spi.o
COBJS := $(COBJS-y)
SRCS := $(COBJS:.o=.c)
diff --git a/drivers/spi/tegra2_spi.c b/drivers/spi/tegra2_spi.c
new file mode 100644
index 0000000..1ad7161
--- /dev/null
+++ b/drivers/spi/tegra2_spi.c
@@ -0,0 +1,276 @@
+/*
+ * Copyright (c) 2010-2011 NVIDIA Corporation
+ * With help from the mpc8xxx SPI driver
+ * With more help from omap3_spi SPI driver
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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 <spi.h>
+#include <asm/io.h>
+#include <asm/gpio.h>
+#include <asm/arch/clk_rst.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/pinmux.h>
+#include <asm/arch/tegra2_spi.h>
+
+struct tegra_spi_slave {
+ struct spi_slave slave;
+ struct spi_tegra *regs;
+ unsigned int freq;
+ unsigned int mode;
+};
+
+static inline struct tegra_spi_slave *to_tegra_spi(struct spi_slave *slave)
+{
+ return container_of(slave, struct tegra_spi_slave, slave);
+}
+
+int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+ /* Tegra2 SPI-Flash - only 1 device ('bus/cs') */
+ if (bus > 0 && cs != 0)
+ return 0;
+ else
+ return 1;
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+ unsigned int max_hz, unsigned int mode)
+{
+ struct tegra_spi_slave *spi;
+
+ if (!spi_cs_is_valid(bus, cs))
+ return NULL;
+
+ if (bus != 0) {
+ printf("SPI error: unsupported bus %d\n", bus);
+ return NULL;
+ }
+ if (cs != 0) {
+ printf("SPI error: unsupported chip select %d on bus %d\n",
+ cs, bus);
+ return NULL;
+ }
+ if (mode > SPI_MODE_3) {
+ printf("SPI error: unsupported SPI mode %i\n", mode);
+ return NULL;
+ }
+
+ if (max_hz > TEGRA2_SPI_MAX_FREQ) {
+ printf("SPI error: unsupported frequency %d Hz. Max frequency"
+ " is %d Hz\n", max_hz, TEGRA2_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->freq = max_hz;
+ spi->regs = (struct spi_tegra *)TEGRA2_SPI_BASE;
+ spi->mode = mode;
+
+ return &spi->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+ struct tegra_spi_slave *spi = to_tegra_spi(slave);
+
+ free(spi);
+}
+
+void spi_init(void)
+{
+ /* do nothing */
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+ struct tegra_spi_slave *spi = to_tegra_spi(slave);
+ struct spi_tegra *regs = spi->regs;
+ u32 reg;
+
+ /* Change SPI clock to correct frequency, PLLP_OUT0 source */
+ clock_start_periph_pll(PERIPH_ID_SPI1, CLOCK_ID_PERIPH, spi->freq);
+
+ /* Clear stale status here */
+ reg = SPI_STAT_RDY | SPI_STAT_RXF_FLUSH | SPI_STAT_TXF_FLUSH | \
+ SPI_STAT_RXF_UNR | SPI_STAT_TXF_OVF;
+ writel(reg, ®s->status);
+ debug("spi_init: STATUS = %08x\n", readl(®s->status));
+
+ /*
+ * Use sw-controlled CS, so we can clock in data after ReadID, etc.
+ */
+ reg = (spi->mode & 1) << SPI_CMD_ACTIVE_SDA_SHIFT;
+ if (spi->mode & 2)
+ reg |= 1 << SPI_CMD_ACTIVE_SCLK_SHIFT;
+ clrsetbits_le32(®s->command, SPI_CMD_ACTIVE_SCLK_MASK |
+ SPI_CMD_ACTIVE_SDA_MASK, SPI_CMD_CS_SOFT | reg);
+ debug("spi_init: COMMAND = %08x\n", readl(®s->command));
+
+ /*
+ * SPI pins on Tegra2 are muxed - change pinmux later due to UART
+ * issue.
+ */
+ pinmux_set_func(PINGRP_GMD, PMUX_FUNC_SFLASH);
+ pinmux_tristate_disable(PINGRP_LSPI);
+ return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+ /*
+ * We can't release UART_DISABLE and set pinmux to UART4 here since
+ * some code (e,g, spi_flash_probe) uses printf() while the SPI
+ * bus is held. That is arguably bad, but it has the advantage of
+ * already being in the source tree.
+ */
+}
+
+void spi_cs_activate(struct spi_slave *slave)
+{
+ struct tegra_spi_slave *spi = to_tegra_spi(slave);
+
+ /* CS is negated on Tegra, so drive a 1 to get a 0 */
+ setbits_le32(&spi->regs->command, SPI_CMD_CS_VAL);
+}
+
+void spi_cs_deactivate(struct spi_slave *slave)
+{
+ struct tegra_spi_slave *spi = to_tegra_spi(slave);
+
+ /* CS is negated on Tegra, so drive a 0 to get a 1 */
+ clrbits_le32(&spi->regs->command, SPI_CMD_CS_VAL);
+}
+
+int 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_tegra *regs = spi->regs;
+ u32 reg, tmpdout, tmpdin = 0;
+ const u8 *dout = data_out;
+ u8 *din = data_in;
+ int num_bytes;
+ int ret;
+
+ debug("spi_xfer: slave %u:%u dout %08X din %08X bitlen %u\n",
+ slave->bus, slave->cs, *(u8 *)dout, *(u8 *)din, bitlen);
+ if (bitlen & 7)
+ return -1;
+ num_bytes = bitlen / 8;
+
+ ret = 0;
+
+ reg = readl(®s->status);
+ writel(reg, ®s->status); /* Clear all SPI events via R/W */
+ debug("spi_xfer entry: STATUS = %08x\n", reg);
+
+ reg = readl(®s->command);
+ reg |= SPI_CMD_TXEN | SPI_CMD_RXEN;
+ writel(reg, ®s->command);
+ debug("spi_xfer: COMMAND = %08x\n", readl(®s->command));
+
+ 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];
+ }
+
+ num_bytes -= bytes;
+ if (dout)
+ dout += bytes;
+
+ clrsetbits_le32(®s->command, SPI_CMD_BIT_LENGTH_MASK,
+ bytes * 8 - 1);
+ writel(tmpdout, ®s->tx_fifo);
+ setbits_le32(®s->command, SPI_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 & SPI_STAT_TXF_EMPTY))
+ break;
+
+ if ((status & (SPI_STAT_BSY | SPI_STAT_RDY)) !=
+ SPI_STAT_RDY)
+ tm++;
+
+ else if (!(status & SPI_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(slave);
+
+ debug("spi_xfer: transfer ended. Value=%08x, status = %08x\n",
+ tmpdin, readl(®s->status));
+
+ if (ret) {
+ printf("spi_xfer: timeout during SPI transfer, tm %d\n", ret);
+ return -1;
+ }
+
+ return 0;
+}
--
1.7.3.1
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