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 } 186