| 1 | /* |
| 2 | * (C) Copyright 2010 |
| 3 | * Michael Kurz <michi.kurz@googlemail.com> |
| 4 | * |
| 5 | * See file CREDITS for list of people who contributed to this |
| 6 | * project. |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU General Public License as |
| 10 | * published by the Free Software Foundation; either version 2 of |
| 11 | * the License, or (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * along with this program; if not, write to the Free Software |
| 20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
| 21 | * MA 02111-1307 USA |
| 22 | */ |
| 23 | |
| 24 | #include <common.h> |
| 25 | #include <malloc.h> |
| 26 | #include <spi.h> |
| 27 | |
| 28 | #include <asm/addrspace.h> |
| 29 | #include <asm/types.h> |
| 30 | #include <asm/ar71xx.h> |
| 31 | |
| 32 | /*----------------------------------------------------------------------- |
| 33 | * Definitions |
| 34 | */ |
| 35 | |
| 36 | #ifdef DEBUG_SPI |
| 37 | #define PRINTD(fmt,args...) printf (fmt ,##args) |
| 38 | #else |
| 39 | #define PRINTD(fmt,args...) |
| 40 | #endif |
| 41 | |
| 42 | struct ar71xx_spi_slave { |
| 43 | struct spi_slave slave; |
| 44 | unsigned int mode; |
| 45 | }; |
| 46 | |
| 47 | static inline struct ar71xx_spi_slave *to_ar71xx_spi(struct spi_slave *slave) |
| 48 | { |
| 49 | return container_of(slave, struct ar71xx_spi_slave, slave); |
| 50 | } |
| 51 | |
| 52 | /*=====================================================================*/ |
| 53 | /* Public Functions */ |
| 54 | /*=====================================================================*/ |
| 55 | |
| 56 | /*----------------------------------------------------------------------- |
| 57 | * Initialization |
| 58 | */ |
| 59 | |
| 60 | void spi_init() |
| 61 | { |
| 62 | PRINTD("ar71xx_spi: spi_init"); |
| 63 | |
| 64 | // Init SPI Hardware, disable remap, set clock |
| 65 | __raw_writel(0x43, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_CTRL)); |
| 66 | |
| 67 | PRINTD(" ---> out\n"); |
| 68 | } |
| 69 | |
| 70 | struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, |
| 71 | unsigned int max_hz, unsigned int mode) |
| 72 | { |
| 73 | struct ar71xx_spi_slave *ss; |
| 74 | |
| 75 | PRINTD("ar71xx_spi: spi_setup_slave"); |
| 76 | |
| 77 | if ((bus != 0) || (cs > 2)) |
| 78 | return NULL; |
| 79 | |
| 80 | ss = malloc(sizeof(struct ar71xx_spi_slave)); |
| 81 | if (!ss) |
| 82 | return NULL; |
| 83 | |
| 84 | ss->slave.bus = bus; |
| 85 | ss->slave.cs = cs; |
| 86 | ss->mode = mode; |
| 87 | |
| 88 | /* TODO: Use max_hz to limit the SCK rate */ |
| 89 | |
| 90 | PRINTD(" ---> out\n"); |
| 91 | |
| 92 | return &ss->slave; |
| 93 | } |
| 94 | |
| 95 | void spi_free_slave(struct spi_slave *slave) |
| 96 | { |
| 97 | struct ar71xx_spi_slave *ss = to_ar71xx_spi(slave); |
| 98 | |
| 99 | free(ss); |
| 100 | } |
| 101 | |
| 102 | int spi_claim_bus(struct spi_slave *slave) |
| 103 | { |
| 104 | |
| 105 | return 0; |
| 106 | } |
| 107 | |
| 108 | void spi_release_bus(struct spi_slave *slave) |
| 109 | { |
| 110 | |
| 111 | } |
| 112 | |
| 113 | int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, |
| 114 | void *din, unsigned long flags) |
| 115 | { |
| 116 | struct ar71xx_spi_slave *ss = to_ar71xx_spi(slave); |
| 117 | uint8_t *rx = din; |
| 118 | const uint8_t *tx = dout; |
| 119 | uint8_t curbyte, curbitlen, restbits; |
| 120 | uint32_t bytes = bitlen / 8; |
| 121 | uint32_t out; |
| 122 | uint32_t in; |
| 123 | |
| 124 | PRINTD("ar71xx_spi: spi_xfer: slave:%p bitlen:%08x dout:%p din:%p flags:%08x\n", slave, bitlen, dout, din, flags); |
| 125 | |
| 126 | if (flags & SPI_XFER_BEGIN) { |
| 127 | __raw_writel(SPI_FS_GPIO, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_FS)); |
| 128 | __raw_writel(SPI_IOC_CS_ALL, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_IOC)); |
| 129 | } |
| 130 | |
| 131 | restbits = (bitlen % 8); |
| 132 | if (restbits != 0) |
| 133 | bytes++; |
| 134 | |
| 135 | // enable chip select |
| 136 | out = SPI_IOC_CS_ALL & ~(SPI_IOC_CS(slave->cs)); |
| 137 | |
| 138 | while (bytes--) { |
| 139 | |
| 140 | curbyte = 0; |
| 141 | if (tx) { |
| 142 | curbyte = *tx++; |
| 143 | } |
| 144 | |
| 145 | if (restbits != 0) { |
| 146 | curbitlen = restbits; |
| 147 | curbyte <<= 8 - restbits; |
| 148 | } else { |
| 149 | curbitlen = 8; |
| 150 | } |
| 151 | |
| 152 | PRINTD("ar71xx_spi: sending: data:%02x length:%d\n", curbyte, curbitlen); |
| 153 | |
| 154 | /* clock starts at inactive polarity */ |
| 155 | for (curbyte <<= (8 - curbitlen); curbitlen; curbitlen--) { |
| 156 | |
| 157 | if (curbyte & (1 << 7)) |
| 158 | out |= SPI_IOC_DO; |
| 159 | else |
| 160 | out &= ~(SPI_IOC_DO); |
| 161 | |
| 162 | /* setup MSB (to slave) on trailing edge */ |
| 163 | __raw_writel(out, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_IOC)); |
| 164 | |
| 165 | __raw_writel(out | SPI_IOC_CLK, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_IOC)); |
| 166 | |
| 167 | curbyte <<= 1; |
| 168 | } |
| 169 | |
| 170 | in = __raw_readl(KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_RDS)); |
| 171 | PRINTD("ar71xx_spi: received:%02x\n", in); |
| 172 | |
| 173 | if (rx) { |
| 174 | if (restbits == 0) { |
| 175 | *rx++ = in; |
| 176 | } else { |
| 177 | *rx++ = (in << (8 - restbits)); |
| 178 | } |
| 179 | } |
| 180 | } |
| 181 | |
| 182 | if (flags & SPI_XFER_END) { |
| 183 | __raw_writel(SPI_IOC_CS(slave->cs), KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_IOC)); |
| 184 | __raw_writel(SPI_IOC_CS_ALL, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_IOC)); |
| 185 | __raw_writel(0, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_FS)); |
| 186 | } |
| 187 | |
| 188 | PRINTD(" ---> out\n"); |
| 189 | |
| 190 | return 0; |
| 191 | } |
| 192 | |
