1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Altera SPI driver 4 * 5 * based on bfin_spi.c 6 * Copyright (c) 2005-2008 Analog Devices Inc. 7 * Copyright (C) 2010 Thomas Chou <thomas (at) wytron.com.tw> 8 */ 9 #include <common.h> 10 #include <dm.h> 11 #include <errno.h> 12 #include <malloc.h> 13 #include <fdtdec.h> 14 #include <spi.h> 15 #include <asm/io.h> 16 17 #define ALTERA_SPI_STATUS_RRDY_MSK BIT(7) 18 #define ALTERA_SPI_CONTROL_SSO_MSK BIT(10) 19 20 #ifndef CONFIG_ALTERA_SPI_IDLE_VAL 21 #define CONFIG_ALTERA_SPI_IDLE_VAL 0xff 22 #endif 23 24 struct altera_spi_regs { 25 u32 rxdata; 26 u32 txdata; 27 u32 status; 28 u32 control; 29 u32 _reserved; 30 u32 slave_sel; 31 }; 32 33 struct altera_spi_platdata { 34 struct altera_spi_regs *regs; 35 }; 36 37 struct altera_spi_priv { 38 struct altera_spi_regs *regs; 39 }; 40 41 static void spi_cs_activate(struct udevice *dev, uint cs) 42 { 43 struct udevice *bus = dev->parent; 44 struct altera_spi_priv *priv = dev_get_priv(bus); 45 struct altera_spi_regs *const regs = priv->regs; 46 47 writel(1 << cs, ®s->slave_sel); 48 writel(ALTERA_SPI_CONTROL_SSO_MSK, ®s->control); 49 } 50 51 static void spi_cs_deactivate(struct udevice *dev) 52 { 53 struct udevice *bus = dev->parent; 54 struct altera_spi_priv *priv = dev_get_priv(bus); 55 struct altera_spi_regs *const regs = priv->regs; 56 57 writel(0, ®s->control); 58 writel(0, ®s->slave_sel); 59 } 60 61 static int altera_spi_claim_bus(struct udevice *dev) 62 { 63 struct udevice *bus = dev->parent; 64 struct altera_spi_priv *priv = dev_get_priv(bus); 65 struct altera_spi_regs *const regs = priv->regs; 66 67 writel(0, ®s->control); 68 writel(0, ®s->slave_sel); 69 70 return 0; 71 } 72 73 static int altera_spi_release_bus(struct udevice *dev) 74 { 75 struct udevice *bus = dev->parent; 76 struct altera_spi_priv *priv = dev_get_priv(bus); 77 struct altera_spi_regs *const regs = priv->regs; 78 79 writel(0, ®s->slave_sel); 80 81 return 0; 82 } 83 84 static int altera_spi_xfer(struct udevice *dev, unsigned int bitlen, 85 const void *dout, void *din, unsigned long flags) 86 { 87 struct udevice *bus = dev->parent; 88 struct altera_spi_priv *priv = dev_get_priv(bus); 89 struct altera_spi_regs *const regs = priv->regs; 90 struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev); 91 92 /* assume spi core configured to do 8 bit transfers */ 93 unsigned int bytes = bitlen / 8; 94 const unsigned char *txp = dout; 95 unsigned char *rxp = din; 96 uint32_t reg, data, start; 97 98 debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__, 99 bus->seq, slave_plat->cs, bitlen, bytes, flags); 100 101 if (bitlen == 0) 102 goto done; 103 104 if (bitlen % 8) { 105 flags |= SPI_XFER_END; 106 goto done; 107 } 108 109 /* empty read buffer */ 110 if (readl(®s->status) & ALTERA_SPI_STATUS_RRDY_MSK) 111 readl(®s->rxdata); 112 113 if (flags & SPI_XFER_BEGIN) 114 spi_cs_activate(dev, slave_plat->cs); 115 116 while (bytes--) { 117 if (txp) 118 data = *txp++; 119 else 120 data = CONFIG_ALTERA_SPI_IDLE_VAL; 121 122 debug("%s: tx:%x ", __func__, data); 123 writel(data, ®s->txdata); 124 125 start = get_timer(0); 126 while (1) { 127 reg = readl(®s->status); 128 if (reg & ALTERA_SPI_STATUS_RRDY_MSK) 129 break; 130 if (get_timer(start) > (CONFIG_SYS_HZ / 1000)) { 131 debug("%s: Transmission timed out!\n", __func__); 132 return -1; 133 } 134 } 135 136 data = readl(®s->rxdata); 137 if (rxp) 138 *rxp++ = data & 0xff; 139 140 debug("rx:%x\n", data); 141 } 142 143 done: 144 if (flags & SPI_XFER_END) 145 spi_cs_deactivate(dev); 146 147 return 0; 148 } 149 150 static int altera_spi_set_speed(struct udevice *bus, uint speed) 151 { 152 return 0; 153 } 154 155 static int altera_spi_set_mode(struct udevice *bus, uint mode) 156 { 157 return 0; 158 } 159 160 static int altera_spi_probe(struct udevice *bus) 161 { 162 struct altera_spi_platdata *plat = dev_get_platdata(bus); 163 struct altera_spi_priv *priv = dev_get_priv(bus); 164 165 priv->regs = plat->regs; 166 167 return 0; 168 } 169 170 static int altera_spi_ofdata_to_platdata(struct udevice *bus) 171 { 172 struct altera_spi_platdata *plat = dev_get_platdata(bus); 173 174 plat->regs = map_physmem(devfdt_get_addr(bus), 175 sizeof(struct altera_spi_regs), 176 MAP_NOCACHE); 177 178 return 0; 179 } 180 181 static const struct dm_spi_ops altera_spi_ops = { 182 .claim_bus = altera_spi_claim_bus, 183 .release_bus = altera_spi_release_bus, 184 .xfer = altera_spi_xfer, 185 .set_speed = altera_spi_set_speed, 186 .set_mode = altera_spi_set_mode, 187 /* 188 * cs_info is not needed, since we require all chip selects to be 189 * in the device tree explicitly 190 */ 191 }; 192 193 static const struct udevice_id altera_spi_ids[] = { 194 { .compatible = "altr,spi-1.0" }, 195 {} 196 }; 197 198 U_BOOT_DRIVER(altera_spi) = { 199 .name = "altera_spi", 200 .id = UCLASS_SPI, 201 .of_match = altera_spi_ids, 202 .ops = &altera_spi_ops, 203 .ofdata_to_platdata = altera_spi_ofdata_to_platdata, 204 .platdata_auto_alloc_size = sizeof(struct altera_spi_platdata), 205 .priv_auto_alloc_size = sizeof(struct altera_spi_priv), 206 .probe = altera_spi_probe, 207 }; 208
