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[people/ms/u-boot.git] / drivers / spi / kirkwood_spi.c
1 /*
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>
30 #include <asm/io.h>
31 #include <asm/arch/kirkwood.h>
32 #include <asm/arch/spi.h>
33 #include <asm/arch/mpp.h>
34
35 static struct kwspi_registers *spireg = (struct kwspi_registers *)KW_SPI_BASE;
36
37 u32 cs_spi_mpp_back[2];
38
39 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
40 unsigned int max_hz, unsigned int mode)
41 {
42 struct spi_slave *slave;
43 u32 data;
44 static const u32 kwspi_mpp_config[2][2] = {
45 { MPP0_SPI_SCn, 0 }, /* if cs == 0 */
46 { MPP7_SPI_SCn, 0 } /* if cs != 0 */
47 };
48
49 if (!spi_cs_is_valid(bus, cs))
50 return NULL;
51
52 slave = malloc(sizeof(struct spi_slave));
53 if (!slave)
54 return NULL;
55
56 slave->bus = bus;
57 slave->cs = cs;
58
59 writel(~KWSPI_CSN_ACT | KWSPI_SMEMRDY, &spireg->ctrl);
60
61 /* calculate spi clock prescaller using max_hz */
62 data = ((CONFIG_SYS_TCLK / 2) / max_hz) + 0x10;
63 data = data < KWSPI_CLKPRESCL_MIN ? KWSPI_CLKPRESCL_MIN : data;
64 data = data > KWSPI_CLKPRESCL_MASK ? KWSPI_CLKPRESCL_MASK : data;
65
66 /* program spi clock prescaller using max_hz */
67 writel(KWSPI_ADRLEN_3BYTE | data, &spireg->cfg);
68 debug("data = 0x%08x \n", data);
69
70 writel(KWSPI_SMEMRDIRQ, &spireg->irq_cause);
71 writel(KWSPI_IRQMASK, &spireg->irq_mask);
72
73 /* program mpp registers to select SPI_CSn */
74 kirkwood_mpp_conf(kwspi_mpp_config[cs ? 1 : 0], cs_spi_mpp_back);
75
76 return slave;
77 }
78
79 void spi_free_slave(struct spi_slave *slave)
80 {
81 kirkwood_mpp_conf(cs_spi_mpp_back, NULL);
82 free(slave);
83 }
84
85 #if defined(CONFIG_SYS_KW_SPI_MPP)
86 u32 spi_mpp_backup[4];
87 #endif
88
89 __attribute__((weak)) int board_spi_claim_bus(struct spi_slave *slave)
90 {
91 return 0;
92 }
93
94 int spi_claim_bus(struct spi_slave *slave)
95 {
96 #if defined(CONFIG_SYS_KW_SPI_MPP)
97 u32 config;
98 u32 spi_mpp_config[4];
99
100 config = CONFIG_SYS_KW_SPI_MPP;
101
102 if (config & MOSI_MPP6)
103 spi_mpp_config[0] = MPP6_SPI_MOSI;
104 else
105 spi_mpp_config[0] = MPP1_SPI_MOSI;
106
107 if (config & SCK_MPP10)
108 spi_mpp_config[1] = MPP10_SPI_SCK;
109 else
110 spi_mpp_config[1] = MPP2_SPI_SCK;
111
112 if (config & MISO_MPP11)
113 spi_mpp_config[2] = MPP11_SPI_MISO;
114 else
115 spi_mpp_config[2] = MPP3_SPI_MISO;
116
117 spi_mpp_config[3] = 0;
118 spi_mpp_backup[3] = 0;
119
120 /* set new spi mpp and save current mpp config */
121 kirkwood_mpp_conf(spi_mpp_config, spi_mpp_backup);
122
123 #endif
124
125 return board_spi_claim_bus(slave);
126 }
127
128 __attribute__((weak)) void board_spi_release_bus(struct spi_slave *slave)
129 {
130 }
131
132 void spi_release_bus(struct spi_slave *slave)
133 {
134 #if defined(CONFIG_SYS_KW_SPI_MPP)
135 kirkwood_mpp_conf(spi_mpp_backup, NULL);
136 #endif
137
138 board_spi_release_bus(slave);
139 }
140
141 #ifndef CONFIG_SPI_CS_IS_VALID
142 /*
143 * you can define this function board specific
144 * define above CONFIG in board specific config file and
145 * provide the function in board specific src file
146 */
147 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
148 {
149 return (bus == 0 && (cs == 0 || cs == 1));
150 }
151 #endif
152
153 void spi_init(void)
154 {
155 }
156
157 void spi_cs_activate(struct spi_slave *slave)
158 {
159 writel(readl(&spireg->ctrl) | KWSPI_IRQUNMASK, &spireg->ctrl);
160 }
161
162 void spi_cs_deactivate(struct spi_slave *slave)
163 {
164 writel(readl(&spireg->ctrl) & KWSPI_IRQMASK, &spireg->ctrl);
165 }
166
167 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
168 void *din, unsigned long flags)
169 {
170 unsigned int tmpdout, tmpdin;
171 int tm, isread = 0;
172
173 debug("spi_xfer: slave %u:%u dout %p din %p bitlen %u\n",
174 slave->bus, slave->cs, dout, din, bitlen);
175
176 if (flags & SPI_XFER_BEGIN)
177 spi_cs_activate(slave);
178
179 /*
180 * handle data in 8-bit chunks
181 * TBD: 2byte xfer mode to be enabled
182 */
183 writel(((readl(&spireg->cfg) & ~KWSPI_XFERLEN_MASK) |
184 KWSPI_XFERLEN_1BYTE), &spireg->cfg);
185
186 while (bitlen > 4) {
187 debug("loopstart bitlen %d\n", bitlen);
188 tmpdout = 0;
189
190 /* Shift data so it's msb-justified */
191 if (dout)
192 tmpdout = *(u32 *) dout & 0x0ff;
193
194 writel(~KWSPI_SMEMRDIRQ, &spireg->irq_cause);
195 writel(tmpdout, &spireg->dout); /* Write the data out */
196 debug("*** spi_xfer: ... %08x written, bitlen %d\n",
197 tmpdout, bitlen);
198
199 /*
200 * Wait for SPI transmit to get out
201 * or time out (1 second = 1000 ms)
202 * The NE event must be read and cleared first
203 */
204 for (tm = 0, isread = 0; tm < KWSPI_TIMEOUT; ++tm) {
205 if (readl(&spireg->irq_cause) & KWSPI_SMEMRDIRQ) {
206 isread = 1;
207 tmpdin = readl(&spireg->din);
208 debug
209 ("spi_xfer: din %p..%08x read\n",
210 din, tmpdin);
211
212 if (din) {
213 *((u8 *) din) = (u8) tmpdin;
214 din += 1;
215 }
216 if (dout)
217 dout += 1;
218 bitlen -= 8;
219 }
220 if (isread)
221 break;
222 }
223 if (tm >= KWSPI_TIMEOUT)
224 printf("*** spi_xfer: Time out during SPI transfer\n");
225
226 debug("loopend bitlen %d\n", bitlen);
227 }
228
229 if (flags & SPI_XFER_END)
230 spi_cs_deactivate(slave);
231
232 return 0;
233 }