2 * Copyright (c) 2010-2012 NVIDIA Corporation
3 * With help from the mpc8xxx SPI driver
4 * With more help from omap3_spi SPI driver
6 * See file CREDITS for list of people who contributed to this
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation; either version 2 of
12 * the License, or (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
29 #include <asm/arch/clock.h>
30 #include <asm/arch/pinmux.h>
31 #include <asm/arch-tegra/clk_rst.h>
32 #include <asm/arch-tegra/tegra_spi.h>
36 DECLARE_GLOBAL_DATA_PTR;
38 struct tegra_spi_slave {
39 struct spi_slave slave;
40 struct spi_tegra *regs;
46 static inline struct tegra_spi_slave *to_tegra_spi(struct spi_slave *slave)
48 return container_of(slave, struct tegra_spi_slave, slave);
51 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
53 /* Tegra20 SPI-Flash - only 1 device ('bus/cs') */
54 if (bus != 0 || cs != 0)
60 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
61 unsigned int max_hz, unsigned int mode)
63 struct tegra_spi_slave *spi;
65 if (!spi_cs_is_valid(bus, cs)) {
66 printf("SPI error: unsupported bus %d / chip select %d\n",
71 if (max_hz > TEGRA_SPI_MAX_FREQ) {
72 printf("SPI error: unsupported frequency %d Hz. Max frequency"
73 " is %d Hz\n", max_hz, TEGRA_SPI_MAX_FREQ);
77 spi = malloc(sizeof(struct tegra_spi_slave));
79 printf("SPI error: malloc of SPI structure failed\n");
84 #ifdef CONFIG_OF_CONTROL
85 int node = fdtdec_next_compatible(gd->fdt_blob, 0,
86 COMPAT_NVIDIA_TEGRA20_SFLASH);
88 debug("%s: cannot locate sflash node\n", __func__);
91 if (!fdtdec_get_is_enabled(gd->fdt_blob, node)) {
92 debug("%s: sflash is disabled\n", __func__);
95 spi->regs = (struct spi_tegra *)fdtdec_get_addr(gd->fdt_blob,
97 if ((fdt_addr_t)spi->regs == FDT_ADDR_T_NONE) {
98 debug("%s: no sflash register found\n", __func__);
101 spi->freq = fdtdec_get_int(gd->fdt_blob, node, "spi-max-frequency", 0);
103 debug("%s: no sflash max frequency found\n", __func__);
106 spi->periph_id = clock_decode_periph_id(gd->fdt_blob, node);
107 if (spi->periph_id == PERIPH_ID_NONE) {
108 debug("%s: could not decode periph id\n", __func__);
112 spi->regs = (struct spi_tegra *)NV_PA_SPI_BASE;
113 spi->freq = TEGRA_SPI_MAX_FREQ;
114 spi->periph_id = PERIPH_ID_SPI1;
116 if (max_hz < spi->freq) {
117 debug("%s: limiting frequency from %u to %u\n", __func__,
121 debug("%s: controller initialized at %p, freq = %u, periph_id = %d\n",
122 __func__, spi->regs, spi->freq, spi->periph_id);
128 void spi_free_slave(struct spi_slave *slave)
130 struct tegra_spi_slave *spi = to_tegra_spi(slave);
140 int spi_claim_bus(struct spi_slave *slave)
142 struct tegra_spi_slave *spi = to_tegra_spi(slave);
143 struct spi_tegra *regs = spi->regs;
146 /* Change SPI clock to correct frequency, PLLP_OUT0 source */
147 clock_start_periph_pll(spi->periph_id, CLOCK_ID_PERIPH, spi->freq);
149 /* Clear stale status here */
150 reg = SPI_STAT_RDY | SPI_STAT_RXF_FLUSH | SPI_STAT_TXF_FLUSH | \
151 SPI_STAT_RXF_UNR | SPI_STAT_TXF_OVF;
152 writel(reg, ®s->status);
153 debug("spi_init: STATUS = %08x\n", readl(®s->status));
156 * Use sw-controlled CS, so we can clock in data after ReadID, etc.
158 reg = (spi->mode & 1) << SPI_CMD_ACTIVE_SDA_SHIFT;
160 reg |= 1 << SPI_CMD_ACTIVE_SCLK_SHIFT;
161 clrsetbits_le32(®s->command, SPI_CMD_ACTIVE_SCLK_MASK |
162 SPI_CMD_ACTIVE_SDA_MASK, SPI_CMD_CS_SOFT | reg);
163 debug("spi_init: COMMAND = %08x\n", readl(®s->command));
166 * SPI pins on Tegra20 are muxed - change pinmux later due to UART
169 pinmux_set_func(PINGRP_GMD, PMUX_FUNC_SFLASH);
170 pinmux_tristate_disable(PINGRP_LSPI);
171 pinmux_set_func(PINGRP_GMC, PMUX_FUNC_SFLASH);
176 void spi_release_bus(struct spi_slave *slave)
179 * We can't release UART_DISABLE and set pinmux to UART4 here since
180 * some code (e,g, spi_flash_probe) uses printf() while the SPI
181 * bus is held. That is arguably bad, but it has the advantage of
182 * already being in the source tree.
186 void spi_cs_activate(struct spi_slave *slave)
188 struct tegra_spi_slave *spi = to_tegra_spi(slave);
190 /* CS is negated on Tegra, so drive a 1 to get a 0 */
191 setbits_le32(&spi->regs->command, SPI_CMD_CS_VAL);
194 void spi_cs_deactivate(struct spi_slave *slave)
196 struct tegra_spi_slave *spi = to_tegra_spi(slave);
198 /* CS is negated on Tegra, so drive a 0 to get a 1 */
199 clrbits_le32(&spi->regs->command, SPI_CMD_CS_VAL);
202 int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
203 const void *data_out, void *data_in, unsigned long flags)
205 struct tegra_spi_slave *spi = to_tegra_spi(slave);
206 struct spi_tegra *regs = spi->regs;
207 u32 reg, tmpdout, tmpdin = 0;
208 const u8 *dout = data_out;
213 debug("spi_xfer: slave %u:%u dout %08X din %08X bitlen %u\n",
214 slave->bus, slave->cs, *(u8 *)dout, *(u8 *)din, bitlen);
217 num_bytes = bitlen / 8;
221 reg = readl(®s->status);
222 writel(reg, ®s->status); /* Clear all SPI events via R/W */
223 debug("spi_xfer entry: STATUS = %08x\n", reg);
225 reg = readl(®s->command);
226 reg |= SPI_CMD_TXEN | SPI_CMD_RXEN;
227 writel(reg, ®s->command);
228 debug("spi_xfer: COMMAND = %08x\n", readl(®s->command));
230 if (flags & SPI_XFER_BEGIN)
231 spi_cs_activate(slave);
233 /* handle data in 32-bit chunks */
234 while (num_bytes > 0) {
240 bytes = (num_bytes > 4) ? 4 : num_bytes;
243 for (i = 0; i < bytes; ++i)
244 tmpdout = (tmpdout << 8) | dout[i];
251 clrsetbits_le32(®s->command, SPI_CMD_BIT_LENGTH_MASK,
253 writel(tmpdout, ®s->tx_fifo);
254 setbits_le32(®s->command, SPI_CMD_GO);
257 * Wait for SPI transmit FIFO to empty, or to time out.
258 * The RX FIFO status will be read and cleared last
260 for (tm = 0, is_read = 0; tm < SPI_TIMEOUT; ++tm) {
263 status = readl(®s->status);
265 /* We can exit when we've had both RX and TX activity */
266 if (is_read && (status & SPI_STAT_TXF_EMPTY))
269 if ((status & (SPI_STAT_BSY | SPI_STAT_RDY)) !=
273 else if (!(status & SPI_STAT_RXF_EMPTY)) {
274 tmpdin = readl(®s->rx_fifo);
277 /* swap bytes read in */
279 for (i = bytes - 1; i >= 0; --i) {
280 din[i] = tmpdin & 0xff;
288 if (tm >= SPI_TIMEOUT)
291 /* clear ACK RDY, etc. bits */
292 writel(readl(®s->status), ®s->status);
295 if (flags & SPI_XFER_END)
296 spi_cs_deactivate(slave);
298 debug("spi_xfer: transfer ended. Value=%08x, status = %08x\n",
299 tmpdin, readl(®s->status));
302 printf("spi_xfer: timeout during SPI transfer, tm %d\n", ret);