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