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/uart-spi-switch.h>
32 #include <asm/arch-tegra/clk_rst.h>
33 #include <asm/arch-tegra/tegra_spi.h>
36 #if defined(CONFIG_SPI_CORRUPTS_UART)
37 #define corrupt_delay() udelay(CONFIG_SPI_CORRUPTS_UART_DLY);
39 #define corrupt_delay()
42 struct tegra_spi_slave {
43 struct spi_slave slave;
44 struct spi_tegra *regs;
49 static inline struct tegra_spi_slave *to_tegra_spi(struct spi_slave *slave)
51 return container_of(slave, struct tegra_spi_slave, slave);
54 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
56 /* Tegra20 SPI-Flash - only 1 device ('bus/cs') */
57 if (bus != 0 || cs != 0)
63 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
64 unsigned int max_hz, unsigned int mode)
66 struct tegra_spi_slave *spi;
68 if (!spi_cs_is_valid(bus, cs)) {
69 printf("SPI error: unsupported bus %d / chip select %d\n",
74 if (max_hz > TEGRA_SPI_MAX_FREQ) {
75 printf("SPI error: unsupported frequency %d Hz. Max frequency"
76 " is %d Hz\n", max_hz, TEGRA_SPI_MAX_FREQ);
80 spi = malloc(sizeof(struct tegra_spi_slave));
82 printf("SPI error: malloc of SPI structure failed\n");
88 spi->regs = (struct spi_tegra *)NV_PA_SPI_BASE;
94 void spi_free_slave(struct spi_slave *slave)
96 struct tegra_spi_slave *spi = to_tegra_spi(slave);
106 int spi_claim_bus(struct spi_slave *slave)
108 struct tegra_spi_slave *spi = to_tegra_spi(slave);
109 struct spi_tegra *regs = spi->regs;
112 /* Change SPI clock to correct frequency, PLLP_OUT0 source */
113 clock_start_periph_pll(PERIPH_ID_SPI1, CLOCK_ID_PERIPH, spi->freq);
115 /* Clear stale status here */
116 reg = SPI_STAT_RDY | SPI_STAT_RXF_FLUSH | SPI_STAT_TXF_FLUSH | \
117 SPI_STAT_RXF_UNR | SPI_STAT_TXF_OVF;
118 writel(reg, ®s->status);
119 debug("spi_init: STATUS = %08x\n", readl(®s->status));
122 * Use sw-controlled CS, so we can clock in data after ReadID, etc.
124 reg = (spi->mode & 1) << SPI_CMD_ACTIVE_SDA_SHIFT;
126 reg |= 1 << SPI_CMD_ACTIVE_SCLK_SHIFT;
127 clrsetbits_le32(®s->command, SPI_CMD_ACTIVE_SCLK_MASK |
128 SPI_CMD_ACTIVE_SDA_MASK, SPI_CMD_CS_SOFT | reg);
129 debug("spi_init: COMMAND = %08x\n", readl(®s->command));
132 * SPI pins on Tegra20 are muxed - change pinmux later due to UART
135 pinmux_set_func(PINGRP_GMD, PMUX_FUNC_SFLASH);
136 pinmux_tristate_disable(PINGRP_LSPI);
138 #ifndef CONFIG_SPI_UART_SWITCH
141 * Only set PinMux bits 3:2 to SPI here on boards that don't have the
142 * SPI UART switch or subsequent UART data won't go out! See
145 /* TODO: pinmux_set_func(PINGRP_GMC, PMUX_FUNC_SFLASH); */
150 void spi_release_bus(struct spi_slave *slave)
153 * We can't release UART_DISABLE and set pinmux to UART4 here since
154 * some code (e,g, spi_flash_probe) uses printf() while the SPI
155 * bus is held. That is arguably bad, but it has the advantage of
156 * already being in the source tree.
160 void spi_cs_activate(struct spi_slave *slave)
162 struct tegra_spi_slave *spi = to_tegra_spi(slave);
166 /* CS is negated on Tegra, so drive a 1 to get a 0 */
167 setbits_le32(&spi->regs->command, SPI_CMD_CS_VAL);
169 corrupt_delay(); /* Let UART settle */
172 void spi_cs_deactivate(struct spi_slave *slave)
174 struct tegra_spi_slave *spi = to_tegra_spi(slave);
176 pinmux_select_uart();
178 /* CS is negated on Tegra, so drive a 0 to get a 1 */
179 clrbits_le32(&spi->regs->command, SPI_CMD_CS_VAL);
181 corrupt_delay(); /* Let SPI settle */
184 int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
185 const void *data_out, void *data_in, unsigned long flags)
187 struct tegra_spi_slave *spi = to_tegra_spi(slave);
188 struct spi_tegra *regs = spi->regs;
189 u32 reg, tmpdout, tmpdin = 0;
190 const u8 *dout = data_out;
195 debug("spi_xfer: slave %u:%u dout %08X din %08X bitlen %u\n",
196 slave->bus, slave->cs, *(u8 *)dout, *(u8 *)din, bitlen);
199 num_bytes = bitlen / 8;
203 reg = readl(®s->status);
204 writel(reg, ®s->status); /* Clear all SPI events via R/W */
205 debug("spi_xfer entry: STATUS = %08x\n", reg);
207 reg = readl(®s->command);
208 reg |= SPI_CMD_TXEN | SPI_CMD_RXEN;
209 writel(reg, ®s->command);
210 debug("spi_xfer: COMMAND = %08x\n", readl(®s->command));
212 if (flags & SPI_XFER_BEGIN)
213 spi_cs_activate(slave);
215 /* handle data in 32-bit chunks */
216 while (num_bytes > 0) {
222 bytes = (num_bytes > 4) ? 4 : num_bytes;
225 for (i = 0; i < bytes; ++i)
226 tmpdout = (tmpdout << 8) | dout[i];
233 clrsetbits_le32(®s->command, SPI_CMD_BIT_LENGTH_MASK,
235 writel(tmpdout, ®s->tx_fifo);
236 setbits_le32(®s->command, SPI_CMD_GO);
239 * Wait for SPI transmit FIFO to empty, or to time out.
240 * The RX FIFO status will be read and cleared last
242 for (tm = 0, is_read = 0; tm < SPI_TIMEOUT; ++tm) {
245 status = readl(®s->status);
247 /* We can exit when we've had both RX and TX activity */
248 if (is_read && (status & SPI_STAT_TXF_EMPTY))
251 if ((status & (SPI_STAT_BSY | SPI_STAT_RDY)) !=
255 else if (!(status & SPI_STAT_RXF_EMPTY)) {
256 tmpdin = readl(®s->rx_fifo);
259 /* swap bytes read in */
261 for (i = bytes - 1; i >= 0; --i) {
262 din[i] = tmpdin & 0xff;
270 if (tm >= SPI_TIMEOUT)
273 /* clear ACK RDY, etc. bits */
274 writel(readl(®s->status), ®s->status);
277 if (flags & SPI_XFER_END)
278 spi_cs_deactivate(slave);
280 debug("spi_xfer: transfer ended. Value=%08x, status = %08x\n",
281 tmpdin, readl(®s->status));
284 printf("spi_xfer: timeout during SPI transfer, tm %d\n", ret);