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5710de45 PW |
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/arch/kirkwood.h> | |
31 | #include <asm/arch/spi.h> | |
32 | #include <asm/arch/mpp.h> | |
33 | ||
34 | static struct kwspi_registers *spireg = (struct kwspi_registers *)KW_SPI_BASE; | |
35 | ||
36 | struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, | |
37 | unsigned int max_hz, unsigned int mode) | |
38 | { | |
39 | struct spi_slave *slave; | |
40 | u32 data; | |
41 | u32 kwspi_mpp_config[] = { | |
42 | MPP0_GPIO, | |
43 | MPP7_SPI_SCn, | |
44 | 0 | |
45 | }; | |
46 | ||
47 | if (!spi_cs_is_valid(bus, cs)) | |
48 | return NULL; | |
49 | ||
50 | slave = malloc(sizeof(struct spi_slave)); | |
51 | if (!slave) | |
52 | return NULL; | |
53 | ||
54 | slave->bus = bus; | |
55 | slave->cs = cs; | |
56 | ||
57 | writel(~KWSPI_CSN_ACT | KWSPI_SMEMRDY, &spireg->ctrl); | |
58 | ||
59 | /* calculate spi clock prescaller using max_hz */ | |
60 | data = ((CONFIG_SYS_TCLK / 2) / max_hz) & KWSPI_CLKPRESCL_MASK; | |
61 | data |= 0x10; | |
62 | ||
63 | /* program spi clock prescaller using max_hz */ | |
64 | writel(KWSPI_ADRLEN_3BYTE | data, &spireg->cfg); | |
65 | debug("data = 0x%08x \n", data); | |
66 | ||
67 | writel(KWSPI_SMEMRDIRQ, &spireg->irq_cause); | |
68 | writel(KWSPI_IRQMASK, spireg->irq_mask); | |
69 | ||
70 | /* program mpp registers to select SPI_CSn */ | |
71 | if (cs) { | |
72 | kwspi_mpp_config[0] = MPP0_GPIO; | |
73 | kwspi_mpp_config[1] = MPP7_SPI_SCn; | |
74 | } else { | |
75 | kwspi_mpp_config[0] = MPP0_SPI_SCn; | |
76 | kwspi_mpp_config[1] = MPP7_GPO; | |
77 | } | |
78 | kirkwood_mpp_conf(kwspi_mpp_config); | |
79 | ||
80 | return slave; | |
81 | } | |
82 | ||
83 | void spi_free_slave(struct spi_slave *slave) | |
84 | { | |
85 | free(slave); | |
86 | } | |
87 | ||
88 | int spi_claim_bus(struct spi_slave *slave) | |
89 | { | |
90 | return 0; | |
91 | } | |
92 | ||
93 | void spi_release_bus(struct spi_slave *slave) | |
94 | { | |
95 | } | |
96 | ||
97 | #ifndef CONFIG_SPI_CS_IS_VALID | |
98 | /* | |
99 | * you can define this function board specific | |
100 | * define above CONFIG in board specific config file and | |
101 | * provide the function in board specific src file | |
102 | */ | |
103 | int spi_cs_is_valid(unsigned int bus, unsigned int cs) | |
104 | { | |
105 | return (bus == 0 && (cs == 0 || cs == 1)); | |
106 | } | |
107 | #endif | |
108 | ||
109 | void spi_cs_activate(struct spi_slave *slave) | |
110 | { | |
111 | writel(readl(&spireg->ctrl) | KWSPI_IRQUNMASK, &spireg->ctrl); | |
112 | } | |
113 | ||
114 | void spi_cs_deactivate(struct spi_slave *slave) | |
115 | { | |
116 | writel(readl(&spireg->ctrl) & KWSPI_IRQMASK, &spireg->ctrl); | |
117 | } | |
118 | ||
119 | int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, | |
120 | void *din, unsigned long flags) | |
121 | { | |
122 | unsigned int tmpdout, tmpdin; | |
123 | int tm, isread = 0; | |
124 | ||
125 | debug("spi_xfer: slave %u:%u dout %08X din %08X bitlen %u\n", | |
126 | slave->bus, slave->cs, dout, din, bitlen); | |
127 | ||
128 | if (flags & SPI_XFER_BEGIN) | |
129 | spi_cs_activate(slave); | |
130 | ||
131 | /* | |
132 | * handle data in 8-bit chunks | |
133 | * TBD: 2byte xfer mode to be enabled | |
134 | */ | |
135 | writel(((readl(&spireg->cfg) & ~KWSPI_XFERLEN_MASK) | | |
136 | KWSPI_XFERLEN_1BYTE), &spireg->cfg); | |
137 | ||
138 | while (bitlen > 4) { | |
139 | debug("loopstart bitlen %d\n", bitlen); | |
140 | tmpdout = 0; | |
141 | ||
142 | /* Shift data so it's msb-justified */ | |
143 | if (dout) | |
144 | tmpdout = *(u32 *) dout & 0x0ff; | |
145 | ||
146 | writel(~KWSPI_SMEMRDIRQ, &spireg->irq_cause); | |
147 | writel(tmpdout, &spireg->dout); /* Write the data out */ | |
148 | debug("*** spi_xfer: ... %08x written, bitlen %d\n", | |
149 | tmpdout, bitlen); | |
150 | ||
151 | /* | |
152 | * Wait for SPI transmit to get out | |
153 | * or time out (1 second = 1000 ms) | |
154 | * The NE event must be read and cleared first | |
155 | */ | |
156 | for (tm = 0, isread = 0; tm < KWSPI_TIMEOUT; ++tm) { | |
157 | if (readl(&spireg->irq_cause) & KWSPI_SMEMRDIRQ) { | |
158 | isread = 1; | |
159 | tmpdin = readl(&spireg->din); | |
160 | debug | |
161 | ("spi_xfer: din %08x..%08x read\n", | |
162 | din, tmpdin); | |
163 | ||
164 | if (din) { | |
165 | *((u8 *) din) = (u8) tmpdin; | |
166 | din += 1; | |
167 | } | |
168 | if (dout) | |
169 | dout += 1; | |
170 | bitlen -= 8; | |
171 | } | |
172 | if (isread) | |
173 | break; | |
174 | } | |
175 | if (tm >= KWSPI_TIMEOUT) | |
176 | printf("*** spi_xfer: Time out during SPI transfer\n"); | |
177 | ||
178 | debug("loopend bitlen %d\n", bitlen); | |
179 | } | |
180 | ||
181 | if (flags & SPI_XFER_END) | |
182 | spi_cs_deactivate(slave); | |
183 | ||
184 | return 0; | |
185 | } |