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Prafulla Wadaskar5710de42009-05-30 01:13:33 +05301/*
2 * (C) Copyright 2009
3 * Marvell Semiconductor <www.marvell.com>
4 * Written-by: Prafulla Wadaskar <prafulla@marvell.com>
5 *
6 * Derived from drivers/spi/mpc8xxx_spi.c
7 *
8 * See file CREDITS for list of people who contributed to this
9 * project.
10 *
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.
15 *
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.
20 *
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,
24 * MA 02110-1301 USA
25 */
26
27#include <common.h>
28#include <malloc.h>
29#include <spi.h>
Lei Wena7efd712011-10-18 20:11:42 +053030#include <asm/io.h>
Prafulla Wadaskar5710de42009-05-30 01:13:33 +053031#include <asm/arch/kirkwood.h>
32#include <asm/arch/spi.h>
33#include <asm/arch/mpp.h>
34
35static struct kwspi_registers *spireg = (struct kwspi_registers *)KW_SPI_BASE;
36
37struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
38 unsigned int max_hz, unsigned int mode)
39{
40 struct spi_slave *slave;
41 u32 data;
42 u32 kwspi_mpp_config[] = {
43 MPP0_GPIO,
44 MPP7_SPI_SCn,
45 0
46 };
47
48 if (!spi_cs_is_valid(bus, cs))
49 return NULL;
50
51 slave = malloc(sizeof(struct spi_slave));
52 if (!slave)
53 return NULL;
54
55 slave->bus = bus;
56 slave->cs = cs;
57
58 writel(~KWSPI_CSN_ACT | KWSPI_SMEMRDY, &spireg->ctrl);
59
60 /* calculate spi clock prescaller using max_hz */
61 data = ((CONFIG_SYS_TCLK / 2) / max_hz) & KWSPI_CLKPRESCL_MASK;
62 data |= 0x10;
63
64 /* program spi clock prescaller using max_hz */
65 writel(KWSPI_ADRLEN_3BYTE | data, &spireg->cfg);
66 debug("data = 0x%08x \n", data);
67
68 writel(KWSPI_SMEMRDIRQ, &spireg->irq_cause);
69 writel(KWSPI_IRQMASK, spireg->irq_mask);
70
71 /* program mpp registers to select SPI_CSn */
72 if (cs) {
73 kwspi_mpp_config[0] = MPP0_GPIO;
74 kwspi_mpp_config[1] = MPP7_SPI_SCn;
75 } else {
76 kwspi_mpp_config[0] = MPP0_SPI_SCn;
77 kwspi_mpp_config[1] = MPP7_GPO;
78 }
79 kirkwood_mpp_conf(kwspi_mpp_config);
80
81 return slave;
82}
83
84void spi_free_slave(struct spi_slave *slave)
85{
86 free(slave);
87}
88
89int spi_claim_bus(struct spi_slave *slave)
90{
91 return 0;
92}
93
94void spi_release_bus(struct spi_slave *slave)
95{
96}
97
98#ifndef CONFIG_SPI_CS_IS_VALID
99/*
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
103 */
104int spi_cs_is_valid(unsigned int bus, unsigned int cs)
105{
106 return (bus == 0 && (cs == 0 || cs == 1));
107}
108#endif
109
Michael Walleefa4e432011-10-18 20:12:00 +0530110void spi_init(void)
111{
112}
113
Prafulla Wadaskar5710de42009-05-30 01:13:33 +0530114void spi_cs_activate(struct spi_slave *slave)
115{
116 writel(readl(&spireg->ctrl) | KWSPI_IRQUNMASK, &spireg->ctrl);
117}
118
119void spi_cs_deactivate(struct spi_slave *slave)
120{
121 writel(readl(&spireg->ctrl) & KWSPI_IRQMASK, &spireg->ctrl);
122}
123
124int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
125 void *din, unsigned long flags)
126{
127 unsigned int tmpdout, tmpdin;
128 int tm, isread = 0;
129
Marek Vasut2e8f6412011-10-24 23:39:59 +0000130 debug("spi_xfer: slave %u:%u dout %p din %p bitlen %u\n",
Prafulla Wadaskar5710de42009-05-30 01:13:33 +0530131 slave->bus, slave->cs, dout, din, bitlen);
132
133 if (flags & SPI_XFER_BEGIN)
134 spi_cs_activate(slave);
135
136 /*
137 * handle data in 8-bit chunks
138 * TBD: 2byte xfer mode to be enabled
139 */
140 writel(((readl(&spireg->cfg) & ~KWSPI_XFERLEN_MASK) |
141 KWSPI_XFERLEN_1BYTE), &spireg->cfg);
142
143 while (bitlen > 4) {
144 debug("loopstart bitlen %d\n", bitlen);
145 tmpdout = 0;
146
147 /* Shift data so it's msb-justified */
148 if (dout)
149 tmpdout = *(u32 *) dout & 0x0ff;
150
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",
154 tmpdout, bitlen);
155
156 /*
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
160 */
161 for (tm = 0, isread = 0; tm < KWSPI_TIMEOUT; ++tm) {
162 if (readl(&spireg->irq_cause) & KWSPI_SMEMRDIRQ) {
163 isread = 1;
164 tmpdin = readl(&spireg->din);
165 debug
Marek Vasut2e8f6412011-10-24 23:39:59 +0000166 ("spi_xfer: din %p..%08x read\n",
Prafulla Wadaskar5710de42009-05-30 01:13:33 +0530167 din, tmpdin);
168
169 if (din) {
170 *((u8 *) din) = (u8) tmpdin;
171 din += 1;
172 }
173 if (dout)
174 dout += 1;
175 bitlen -= 8;
176 }
177 if (isread)
178 break;
179 }
180 if (tm >= KWSPI_TIMEOUT)
181 printf("*** spi_xfer: Time out during SPI transfer\n");
182
183 debug("loopend bitlen %d\n", bitlen);
184 }
185
186 if (flags & SPI_XFER_END)
187 spi_cs_deactivate(slave);
188
189 return 0;
190}