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path: root/drivers/spi/tegra20_slink.c
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Diffstat (limited to 'drivers/spi/tegra20_slink.c')
-rw-r--r--drivers/spi/tegra20_slink.c343
1 files changed, 343 insertions, 0 deletions
diff --git a/drivers/spi/tegra20_slink.c b/drivers/spi/tegra20_slink.c
new file mode 100644
index 0000000..a6de4ce
--- /dev/null
+++ b/drivers/spi/tegra20_slink.c
@@ -0,0 +1,343 @@
+/*
+ * NVIDIA Tegra SPI-SLINK controller
+ *
+ * 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-tegra20/tegra20_slink.h>
+#include <spi.h>
+#include <fdtdec.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct tegra_spi_ctrl {
+ struct slink_tegra *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_TEGRA_SLINK_CTRLS];
+
+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)
+{
+ if (bus >= CONFIG_TEGRA_SLINK_CTRLS || cs > 3 || !spi_ctrls[bus].valid)
+ 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;
+
+ 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 spi_free_slave(struct spi_slave *slave)
+{
+ struct tegra_spi_slave *spi = to_tegra_spi(slave);
+
+ free(spi);
+}
+
+void spi_init(void)
+{
+ struct tegra_spi_ctrl *ctrl;
+ int i;
+#ifdef CONFIG_OF_CONTROL
+ int node = 0;
+ int count;
+ int node_list[CONFIG_TEGRA_SLINK_CTRLS];
+
+ count = fdtdec_find_aliases_for_id(gd->fdt_blob, "spi",
+ COMPAT_NVIDIA_TEGRA20_SLINK,
+ node_list,
+ CONFIG_TEGRA_SLINK_CTRLS);
+ for (i = 0; i < count; i++) {
+ ctrl = &spi_ctrls[i];
+ node = node_list[i];
+
+ ctrl->regs = (struct slink_tegra *)fdtdec_get_addr(gd->fdt_blob,
+ node, "reg");
+ if ((fdt_addr_t)ctrl->regs == FDT_ADDR_T_NONE) {
+ debug("%s: no slink register found\n", __func__);
+ continue;
+ }
+ ctrl->freq = fdtdec_get_int(gd->fdt_blob, node,
+ "spi-max-frequency", 0);
+ if (!ctrl->freq) {
+ debug("%s: no slink 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;
+
+ debug("%s: found controller at %p, freq = %u, periph_id = %d\n",
+ __func__, ctrl->regs, ctrl->freq, ctrl->periph_id);
+ }
+#else
+ for (i = 0; i < CONFIG_TEGRA_SLINK_CTRLS; i++) {
+ ctrl = &spi_ctrls[i];
+ u32 base_regs[] = {
+ NV_PA_SLINK1_BASE,
+ NV_PA_SLINK2_BASE,
+ NV_PA_SLINK3_BASE,
+ NV_PA_SLINK4_BASE,
+ NV_PA_SLINK5_BASE,
+ NV_PA_SLINK6_BASE,
+ };
+ int periph_ids[] = {
+ PERIPH_ID_SBC1,
+ PERIPH_ID_SBC2,
+ PERIPH_ID_SBC3,
+ PERIPH_ID_SBC4,
+ PERIPH_ID_SBC5,
+ PERIPH_ID_SBC6,
+ };
+ ctrl->regs = (struct slink_tegra *)base_regs[i];
+ ctrl->freq = TEGRA_SPI_MAX_FREQ;
+ ctrl->periph_id = periph_ids[i];
+ ctrl->valid = 1;
+
+ debug("%s: found controller at %p, freq = %u, periph_id = %d\n",
+ __func__, ctrl->regs, ctrl->freq, ctrl->periph_id);
+ }
+#endif
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+ struct tegra_spi_slave *spi = to_tegra_spi(slave);
+ struct slink_tegra *regs = spi->ctrl->regs;
+ u32 reg;
+
+ /* 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 */
+ reg = SLINK_STAT_RDY | SLINK_STAT_RXF_FLUSH | SLINK_STAT_TXF_FLUSH | \
+ SLINK_STAT_RXF_UNR | SLINK_STAT_TXF_OVF;
+ writel(reg, &regs->status);
+ debug("%s: STATUS = %08x\n", __func__, readl(&regs->status));
+
+ /* Set master mode and sw controlled CS */
+ reg = readl(&regs->command);
+ reg |= SLINK_CMD_M_S | SLINK_CMD_CS_SOFT;
+ writel(reg, &regs->command);
+ debug("%s: COMMAND = %08x\n", __func__, readl(&regs->command));
+
+ return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+}
+
+void spi_cs_activate(struct spi_slave *slave)
+{
+ struct tegra_spi_slave *spi = to_tegra_spi(slave);
+ struct slink_tegra *regs = spi->ctrl->regs;
+
+ /* CS is negated on Tegra, so drive a 1 to get a 0 */
+ setbits_le32(&regs->command, SLINK_CMD_CS_VAL);
+}
+
+void spi_cs_deactivate(struct spi_slave *slave)
+{
+ struct tegra_spi_slave *spi = to_tegra_spi(slave);
+ struct slink_tegra *regs = spi->ctrl->regs;
+
+ /* CS is negated on Tegra, so drive a 0 to get a 1 */
+ clrbits_le32(&regs->command, SLINK_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 slink_tegra *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;
+
+ reg = readl(&regs->status);
+ writel(reg, &regs->status); /* Clear all SPI events via R/W */
+ debug("%s entry: STATUS = %08x\n", __func__, reg);
+
+ reg = readl(&regs->status2);
+ writel(reg, &regs->status2); /* Clear all STATUS2 events via R/W */
+ debug("%s entry: STATUS2 = %08x\n", __func__, reg);
+
+ debug("%s entry: COMMAND = %08x\n", __func__, readl(&regs->command));
+
+ clrsetbits_le32(&regs->command2, SLINK_CMD2_SS_EN_MASK,
+ SLINK_CMD2_TXEN | SLINK_CMD2_RXEN |
+ (slave->cs << SLINK_CMD2_SS_EN_SHIFT));
+ debug("%s entry: COMMAND2 = %08x\n", __func__, readl(&regs->command2));
+
+ 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(&regs->command, SLINK_CMD_BIT_LENGTH_MASK,
+ bytes * 8 - 1);
+ writel(tmpdout, &regs->tx_fifo);
+ setbits_le32(&regs->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(&regs->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(&regs->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(&regs->status), &regs->status);
+ }
+
+ if (flags & SPI_XFER_END)
+ spi_cs_deactivate(slave);
+
+ debug("%s: transfer ended. Value=%08x, status = %08x\n",
+ __func__, tmpdin, readl(&regs->status));
+
+ if (ret) {
+ printf("%s: timeout during SPI transfer, tm %d\n",
+ __func__, ret);
+ return -1;
+ }
+
+ return 0;
+}