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git.ipfire.org Git - people/ms/u-boot.git/blob - drivers/spi/kirkwood_spi.c
3 * Marvell Semiconductor <www.marvell.com>
4 * Written-by: Prafulla Wadaskar <prafulla@marvell.com>
6 * Derived from drivers/spi/mpc8xxx_spi.c
8 * See file CREDITS for list of people who contributed to this
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License as
13 * published by the Free Software Foundation; either version 2 of
14 * the License, or (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
31 #include <asm/arch/kirkwood.h>
32 #include <asm/arch/spi.h>
33 #include <asm/arch/mpp.h>
35 static struct kwspi_registers
*spireg
= (struct kwspi_registers
*)KW_SPI_BASE
;
37 struct spi_slave
*spi_setup_slave(unsigned int bus
, unsigned int cs
,
38 unsigned int max_hz
, unsigned int mode
)
40 struct spi_slave
*slave
;
42 u32 kwspi_mpp_config
[] = {
48 if (!spi_cs_is_valid(bus
, cs
))
51 slave
= malloc(sizeof(struct spi_slave
));
58 writel(~KWSPI_CSN_ACT
| KWSPI_SMEMRDY
, &spireg
->ctrl
);
60 /* calculate spi clock prescaller using max_hz */
61 data
= ((CONFIG_SYS_TCLK
/ 2) / max_hz
) & KWSPI_CLKPRESCL_MASK
;
64 /* program spi clock prescaller using max_hz */
65 writel(KWSPI_ADRLEN_3BYTE
| data
, &spireg
->cfg
);
66 debug("data = 0x%08x \n", data
);
68 writel(KWSPI_SMEMRDIRQ
, &spireg
->irq_cause
);
69 writel(KWSPI_IRQMASK
, spireg
->irq_mask
);
71 /* program mpp registers to select SPI_CSn */
73 kwspi_mpp_config
[0] = MPP0_GPIO
;
74 kwspi_mpp_config
[1] = MPP7_SPI_SCn
;
76 kwspi_mpp_config
[0] = MPP0_SPI_SCn
;
77 kwspi_mpp_config
[1] = MPP7_GPO
;
79 kirkwood_mpp_conf(kwspi_mpp_config
);
84 void spi_free_slave(struct spi_slave
*slave
)
89 int spi_claim_bus(struct spi_slave
*slave
)
94 void spi_release_bus(struct spi_slave
*slave
)
98 #ifndef CONFIG_SPI_CS_IS_VALID
100 * you can define this function board specific
101 * define above CONFIG in board specific config file and
102 * provide the function in board specific src file
104 int spi_cs_is_valid(unsigned int bus
, unsigned int cs
)
106 return (bus
== 0 && (cs
== 0 || cs
== 1));
114 void spi_cs_activate(struct spi_slave
*slave
)
116 writel(readl(&spireg
->ctrl
) | KWSPI_IRQUNMASK
, &spireg
->ctrl
);
119 void spi_cs_deactivate(struct spi_slave
*slave
)
121 writel(readl(&spireg
->ctrl
) & KWSPI_IRQMASK
, &spireg
->ctrl
);
124 int spi_xfer(struct spi_slave
*slave
, unsigned int bitlen
, const void *dout
,
125 void *din
, unsigned long flags
)
127 unsigned int tmpdout
, tmpdin
;
130 debug("spi_xfer: slave %u:%u dout %p din %p bitlen %u\n",
131 slave
->bus
, slave
->cs
, dout
, din
, bitlen
);
133 if (flags
& SPI_XFER_BEGIN
)
134 spi_cs_activate(slave
);
137 * handle data in 8-bit chunks
138 * TBD: 2byte xfer mode to be enabled
140 writel(((readl(&spireg
->cfg
) & ~KWSPI_XFERLEN_MASK
) |
141 KWSPI_XFERLEN_1BYTE
), &spireg
->cfg
);
144 debug("loopstart bitlen %d\n", bitlen
);
147 /* Shift data so it's msb-justified */
149 tmpdout
= *(u32
*) dout
& 0x0ff;
151 writel(~KWSPI_SMEMRDIRQ
, &spireg
->irq_cause
);
152 writel(tmpdout
, &spireg
->dout
); /* Write the data out */
153 debug("*** spi_xfer: ... %08x written, bitlen %d\n",
157 * Wait for SPI transmit to get out
158 * or time out (1 second = 1000 ms)
159 * The NE event must be read and cleared first
161 for (tm
= 0, isread
= 0; tm
< KWSPI_TIMEOUT
; ++tm
) {
162 if (readl(&spireg
->irq_cause
) & KWSPI_SMEMRDIRQ
) {
164 tmpdin
= readl(&spireg
->din
);
166 ("spi_xfer: din %p..%08x read\n",
170 *((u8
*) din
) = (u8
) tmpdin
;
180 if (tm
>= KWSPI_TIMEOUT
)
181 printf("*** spi_xfer: Time out during SPI transfer\n");
183 debug("loopend bitlen %d\n", bitlen
);
186 if (flags
& SPI_XFER_END
)
187 spi_cs_deactivate(slave
);