1 /* 2 * Altera SPI driver 3 * 4 * based on bfin_spi.c 5 * Copyright (c) 2005-2008 Analog Devices Inc. 6 * Copyright (C) 2010 Thomas Chou <thomas@wytron.com.tw> 7 * 8 * Licensed under the GPL-2 or later. 9 */ 10 #include <common.h> 11 #include <asm/io.h> 12 #include <malloc.h> 13 #include <spi.h> 14 15 #define ALTERA_SPI_RXDATA 0 16 #define ALTERA_SPI_TXDATA 4 17 #define ALTERA_SPI_STATUS 8 18 #define ALTERA_SPI_CONTROL 12 19 #define ALTERA_SPI_SLAVE_SEL 20 20 21 #define ALTERA_SPI_STATUS_ROE_MSK (0x8) 22 #define ALTERA_SPI_STATUS_TOE_MSK (0x10) 23 #define ALTERA_SPI_STATUS_TMT_MSK (0x20) 24 #define ALTERA_SPI_STATUS_TRDY_MSK (0x40) 25 #define ALTERA_SPI_STATUS_RRDY_MSK (0x80) 26 #define ALTERA_SPI_STATUS_E_MSK (0x100) 27 28 #define ALTERA_SPI_CONTROL_IROE_MSK (0x8) 29 #define ALTERA_SPI_CONTROL_ITOE_MSK (0x10) 30 #define ALTERA_SPI_CONTROL_ITRDY_MSK (0x40) 31 #define ALTERA_SPI_CONTROL_IRRDY_MSK (0x80) 32 #define ALTERA_SPI_CONTROL_IE_MSK (0x100) 33 #define ALTERA_SPI_CONTROL_SSO_MSK (0x400) 34 35 #ifndef CONFIG_SYS_ALTERA_SPI_LIST 36 #define CONFIG_SYS_ALTERA_SPI_LIST { CONFIG_SYS_SPI_BASE } 37 #endif 38 39 static ulong altera_spi_base_list[] = CONFIG_SYS_ALTERA_SPI_LIST; 40 41 struct altera_spi_slave { 42 struct spi_slave slave; 43 ulong base; 44 }; 45 #define to_altera_spi_slave(s) container_of(s, struct altera_spi_slave, slave) 46 47 __attribute__((weak)) 48 int spi_cs_is_valid(unsigned int bus, unsigned int cs) 49 { 50 return bus < ARRAY_SIZE(altera_spi_base_list) && cs < 32; 51 } 52 53 __attribute__((weak)) 54 void spi_cs_activate(struct spi_slave *slave) 55 { 56 struct altera_spi_slave *altspi = to_altera_spi_slave(slave); 57 writel(1 << slave->cs, altspi->base + ALTERA_SPI_SLAVE_SEL); 58 writel(ALTERA_SPI_CONTROL_SSO_MSK, altspi->base + ALTERA_SPI_CONTROL); 59 } 60 61 __attribute__((weak)) 62 void spi_cs_deactivate(struct spi_slave *slave) 63 { 64 struct altera_spi_slave *altspi = to_altera_spi_slave(slave); 65 writel(0, altspi->base + ALTERA_SPI_CONTROL); 66 writel(0, altspi->base + ALTERA_SPI_SLAVE_SEL); 67 } 68 69 void spi_init(void) 70 { 71 } 72 73 void spi_set_speed(struct spi_slave *slave, uint hz) 74 { 75 /* altera spi core does not support programmable speed */ 76 } 77 78 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, 79 unsigned int max_hz, unsigned int mode) 80 { 81 struct altera_spi_slave *altspi; 82 83 if (!spi_cs_is_valid(bus, cs)) 84 return NULL; 85 86 altspi = malloc(sizeof(*altspi)); 87 if (!altspi) 88 return NULL; 89 90 altspi->slave.bus = bus; 91 altspi->slave.cs = cs; 92 altspi->base = altera_spi_base_list[bus]; 93 debug("%s: bus:%i cs:%i base:%lx\n", __func__, 94 bus, cs, altspi->base); 95 96 return &altspi->slave; 97 } 98 99 void spi_free_slave(struct spi_slave *slave) 100 { 101 struct altera_spi_slave *altspi = to_altera_spi_slave(slave); 102 free(altspi); 103 } 104 105 int spi_claim_bus(struct spi_slave *slave) 106 { 107 struct altera_spi_slave *altspi = to_altera_spi_slave(slave); 108 109 debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs); 110 writel(0, altspi->base + ALTERA_SPI_CONTROL); 111 writel(0, altspi->base + ALTERA_SPI_SLAVE_SEL); 112 return 0; 113 } 114 115 void spi_release_bus(struct spi_slave *slave) 116 { 117 struct altera_spi_slave *altspi = to_altera_spi_slave(slave); 118 119 debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs); 120 writel(0, altspi->base + ALTERA_SPI_SLAVE_SEL); 121 } 122 123 #ifndef CONFIG_ALTERA_SPI_IDLE_VAL 124 # define CONFIG_ALTERA_SPI_IDLE_VAL 0xff 125 #endif 126 127 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, 128 void *din, unsigned long flags) 129 { 130 struct altera_spi_slave *altspi = to_altera_spi_slave(slave); 131 /* assume spi core configured to do 8 bit transfers */ 132 uint bytes = bitlen / 8; 133 const uchar *txp = dout; 134 uchar *rxp = din; 135 136 debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__, 137 slave->bus, slave->cs, bitlen, bytes, flags); 138 if (bitlen == 0) 139 goto done; 140 141 if (bitlen % 8) { 142 flags |= SPI_XFER_END; 143 goto done; 144 } 145 146 /* empty read buffer */ 147 if (readl(altspi->base + ALTERA_SPI_STATUS) & 148 ALTERA_SPI_STATUS_RRDY_MSK) 149 readl(altspi->base + ALTERA_SPI_RXDATA); 150 if (flags & SPI_XFER_BEGIN) 151 spi_cs_activate(slave); 152 153 while (bytes--) { 154 uchar d = txp ? *txp++ : CONFIG_ALTERA_SPI_IDLE_VAL; 155 debug("%s: tx:%x ", __func__, d); 156 writel(d, altspi->base + ALTERA_SPI_TXDATA); 157 while (!(readl(altspi->base + ALTERA_SPI_STATUS) & 158 ALTERA_SPI_STATUS_RRDY_MSK)) 159 ; 160 d = readl(altspi->base + ALTERA_SPI_RXDATA); 161 if (rxp) 162 *rxp++ = d; 163 debug("rx:%x\n", d); 164 } 165 done: 166 if (flags & SPI_XFER_END) 167 spi_cs_deactivate(slave); 168 169 return 0; 170 } 171