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 * SPDX-License-Identifier: GPL-2.0+ 9 */ 10 #include <common.h> 11 #include <asm/io.h> 12 #include <malloc.h> 13 #include <spi.h> 14 15 #ifndef CONFIG_ALTERA_SPI_IDLE_VAL 16 #define CONFIG_ALTERA_SPI_IDLE_VAL 0xff 17 #endif 18 19 #ifndef CONFIG_SYS_ALTERA_SPI_LIST 20 #define CONFIG_SYS_ALTERA_SPI_LIST { CONFIG_SYS_SPI_BASE } 21 #endif 22 23 struct altera_spi_regs { 24 u32 rxdata; 25 u32 txdata; 26 u32 status; 27 u32 control; 28 u32 _reserved; 29 u32 slave_sel; 30 }; 31 32 #define ALTERA_SPI_STATUS_ROE_MSK (1 << 3) 33 #define ALTERA_SPI_STATUS_TOE_MSK (1 << 4) 34 #define ALTERA_SPI_STATUS_TMT_MSK (1 << 5) 35 #define ALTERA_SPI_STATUS_TRDY_MSK (1 << 6) 36 #define ALTERA_SPI_STATUS_RRDY_MSK (1 << 7) 37 #define ALTERA_SPI_STATUS_E_MSK (1 << 8) 38 39 #define ALTERA_SPI_CONTROL_IROE_MSK (1 << 3) 40 #define ALTERA_SPI_CONTROL_ITOE_MSK (1 << 4) 41 #define ALTERA_SPI_CONTROL_ITRDY_MSK (1 << 6) 42 #define ALTERA_SPI_CONTROL_IRRDY_MSK (1 << 7) 43 #define ALTERA_SPI_CONTROL_IE_MSK (1 << 8) 44 #define ALTERA_SPI_CONTROL_SSO_MSK (1 << 10) 45 46 static ulong altera_spi_base_list[] = CONFIG_SYS_ALTERA_SPI_LIST; 47 48 struct altera_spi_slave { 49 struct spi_slave slave; 50 struct altera_spi_regs *regs; 51 }; 52 #define to_altera_spi_slave(s) container_of(s, struct altera_spi_slave, slave) 53 54 __weak int spi_cs_is_valid(unsigned int bus, unsigned int cs) 55 { 56 return bus < ARRAY_SIZE(altera_spi_base_list) && cs < 32; 57 } 58 59 __weak void spi_cs_activate(struct spi_slave *slave) 60 { 61 struct altera_spi_slave *altspi = to_altera_spi_slave(slave); 62 writel(1 << slave->cs, &altspi->regs->slave_sel); 63 writel(ALTERA_SPI_CONTROL_SSO_MSK, &altspi->regs->control); 64 } 65 66 __weak void spi_cs_deactivate(struct spi_slave *slave) 67 { 68 struct altera_spi_slave *altspi = to_altera_spi_slave(slave); 69 writel(0, &altspi->regs->control); 70 writel(0, &altspi->regs->slave_sel); 71 } 72 73 void spi_init(void) 74 { 75 } 76 77 void spi_set_speed(struct spi_slave *slave, uint hz) 78 { 79 /* altera spi core does not support programmable speed */ 80 } 81 82 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, 83 unsigned int max_hz, unsigned int mode) 84 { 85 struct altera_spi_slave *altspi; 86 87 if (!spi_cs_is_valid(bus, cs)) 88 return NULL; 89 90 altspi = spi_alloc_slave(struct altera_spi_slave, bus, cs); 91 if (!altspi) 92 return NULL; 93 94 altspi->regs = (struct altera_spi_regs *)altera_spi_base_list[bus]; 95 debug("%s: bus:%i cs:%i base:%p\n", __func__, bus, cs, altspi->regs); 96 97 return &altspi->slave; 98 } 99 100 void spi_free_slave(struct spi_slave *slave) 101 { 102 struct altera_spi_slave *altspi = to_altera_spi_slave(slave); 103 free(altspi); 104 } 105 106 int spi_claim_bus(struct spi_slave *slave) 107 { 108 struct altera_spi_slave *altspi = to_altera_spi_slave(slave); 109 110 debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs); 111 writel(0, &altspi->regs->control); 112 writel(0, &altspi->regs->slave_sel); 113 return 0; 114 } 115 116 void spi_release_bus(struct spi_slave *slave) 117 { 118 struct altera_spi_slave *altspi = to_altera_spi_slave(slave); 119 120 debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs); 121 writel(0, &altspi->regs->slave_sel); 122 } 123 124 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, 125 void *din, unsigned long flags) 126 { 127 struct altera_spi_slave *altspi = to_altera_spi_slave(slave); 128 /* assume spi core configured to do 8 bit transfers */ 129 unsigned int bytes = bitlen / 8; 130 const unsigned char *txp = dout; 131 unsigned char *rxp = din; 132 uint32_t reg, data, start; 133 134 debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__, 135 slave->bus, slave->cs, bitlen, bytes, flags); 136 137 if (bitlen == 0) 138 goto done; 139 140 if (bitlen % 8) { 141 flags |= SPI_XFER_END; 142 goto done; 143 } 144 145 /* empty read buffer */ 146 if (readl(&altspi->regs->status) & ALTERA_SPI_STATUS_RRDY_MSK) 147 readl(&altspi->regs->rxdata); 148 149 if (flags & SPI_XFER_BEGIN) 150 spi_cs_activate(slave); 151 152 while (bytes--) { 153 if (txp) 154 data = *txp++; 155 else 156 data = CONFIG_ALTERA_SPI_IDLE_VAL; 157 158 debug("%s: tx:%x ", __func__, data); 159 writel(data, &altspi->regs->txdata); 160 161 start = get_timer(0); 162 while (1) { 163 reg = readl(&altspi->regs->status); 164 if (reg & ALTERA_SPI_STATUS_RRDY_MSK) 165 break; 166 if (get_timer(start) > (CONFIG_SYS_HZ / 1000)) { 167 printf("%s: Transmission timed out!\n", __func__); 168 goto done; 169 } 170 } 171 172 data = readl(&altspi->regs->rxdata); 173 if (rxp) 174 *rxp++ = data & 0xff; 175 176 debug("rx:%x\n", data); 177 } 178 179 done: 180 if (flags & SPI_XFER_END) 181 spi_cs_deactivate(slave); 182 183 return 0; 184 } 185