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 } 234