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 struct altera_spi_regs { 16 u32 rxdata; 17 u32 txdata; 18 u32 status; 19 u32 control; 20 u32 _reserved; 21 u32 slave_sel; 22 }; 23 24 #define ALTERA_SPI_STATUS_ROE_MSK (1 << 3) 25 #define ALTERA_SPI_STATUS_TOE_MSK (1 << 4) 26 #define ALTERA_SPI_STATUS_TMT_MSK (1 << 5) 27 #define ALTERA_SPI_STATUS_TRDY_MSK (1 << 6) 28 #define ALTERA_SPI_STATUS_RRDY_MSK (1 << 7) 29 #define ALTERA_SPI_STATUS_E_MSK (1 << 8) 30 31 #define ALTERA_SPI_CONTROL_IROE_MSK (1 << 3) 32 #define ALTERA_SPI_CONTROL_ITOE_MSK (1 << 4) 33 #define ALTERA_SPI_CONTROL_ITRDY_MSK (1 << 6) 34 #define ALTERA_SPI_CONTROL_IRRDY_MSK (1 << 7) 35 #define ALTERA_SPI_CONTROL_IE_MSK (1 << 8) 36 #define ALTERA_SPI_CONTROL_SSO_MSK (1 << 10) 37 38 #ifndef CONFIG_SYS_ALTERA_SPI_LIST 39 #define CONFIG_SYS_ALTERA_SPI_LIST { CONFIG_SYS_SPI_BASE } 40 #endif 41 42 static ulong altera_spi_base_list[] = CONFIG_SYS_ALTERA_SPI_LIST; 43 44 struct altera_spi_slave { 45 struct spi_slave slave; 46 struct altera_spi_regs *regs; 47 }; 48 #define to_altera_spi_slave(s) container_of(s, struct altera_spi_slave, slave) 49 50 __weak int spi_cs_is_valid(unsigned int bus, unsigned int cs) 51 { 52 return bus < ARRAY_SIZE(altera_spi_base_list) && cs < 32; 53 } 54 55 __weak void spi_cs_activate(struct spi_slave *slave) 56 { 57 struct altera_spi_slave *altspi = to_altera_spi_slave(slave); 58 writel(1 << slave->cs, &altspi->regs->slave_sel); 59 writel(ALTERA_SPI_CONTROL_SSO_MSK, &altspi->regs->control); 60 } 61 62 __weak void spi_cs_deactivate(struct spi_slave *slave) 63 { 64 struct altera_spi_slave *altspi = to_altera_spi_slave(slave); 65 writel(0, &altspi->regs->control); 66 writel(0, &altspi->regs->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 = spi_alloc_slave(struct altera_spi_slave, bus, cs); 87 if (!altspi) 88 return NULL; 89 90 altspi->regs = (struct altera_spi_regs *)altera_spi_base_list[bus]; 91 debug("%s: bus:%i cs:%i base:%p\n", __func__, bus, cs, altspi->regs); 92 93 return &altspi->slave; 94 } 95 96 void spi_free_slave(struct spi_slave *slave) 97 { 98 struct altera_spi_slave *altspi = to_altera_spi_slave(slave); 99 free(altspi); 100 } 101 102 int spi_claim_bus(struct spi_slave *slave) 103 { 104 struct altera_spi_slave *altspi = to_altera_spi_slave(slave); 105 106 debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs); 107 writel(0, &altspi->regs->control); 108 writel(0, &altspi->regs->slave_sel); 109 return 0; 110 } 111 112 void spi_release_bus(struct spi_slave *slave) 113 { 114 struct altera_spi_slave *altspi = to_altera_spi_slave(slave); 115 116 debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs); 117 writel(0, &altspi->regs->slave_sel); 118 } 119 120 #ifndef CONFIG_ALTERA_SPI_IDLE_VAL 121 # define CONFIG_ALTERA_SPI_IDLE_VAL 0xff 122 #endif 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