1623b6386SSimon Glass /* 2623b6386SSimon Glass * Copyright (c) 2014 Google, Inc 3623b6386SSimon Glass * 4623b6386SSimon Glass * (C) Copyright 2002 5623b6386SSimon Glass * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com. 6623b6386SSimon Glass * 7623b6386SSimon Glass * Influenced by code from: 8623b6386SSimon Glass * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 9623b6386SSimon Glass * 10623b6386SSimon Glass * SPDX-License-Identifier: GPL-2.0+ 11623b6386SSimon Glass */ 12623b6386SSimon Glass 13623b6386SSimon Glass #include <common.h> 14623b6386SSimon Glass #include <dm.h> 15623b6386SSimon Glass #include <errno.h> 16623b6386SSimon Glass #include <fdtdec.h> 17623b6386SSimon Glass #include <malloc.h> 18623b6386SSimon Glass #include <spi.h> 19623b6386SSimon Glass #include <asm/gpio.h> 20623b6386SSimon Glass 21623b6386SSimon Glass DECLARE_GLOBAL_DATA_PTR; 22623b6386SSimon Glass 23623b6386SSimon Glass struct soft_spi_platdata { 24*050fb909SSimon Glass struct gpio_desc cs; 25*050fb909SSimon Glass struct gpio_desc sclk; 26*050fb909SSimon Glass struct gpio_desc mosi; 27*050fb909SSimon Glass struct gpio_desc miso; 28623b6386SSimon Glass int spi_delay_us; 29623b6386SSimon Glass }; 30623b6386SSimon Glass 31623b6386SSimon Glass struct soft_spi_priv { 32623b6386SSimon Glass unsigned int mode; 33623b6386SSimon Glass }; 34623b6386SSimon Glass 35623b6386SSimon Glass static int soft_spi_scl(struct udevice *dev, int bit) 36623b6386SSimon Glass { 37623b6386SSimon Glass struct soft_spi_platdata *plat = dev->platdata; 38623b6386SSimon Glass 39*050fb909SSimon Glass dm_gpio_set_value(&plat->sclk, bit); 40623b6386SSimon Glass 41623b6386SSimon Glass return 0; 42623b6386SSimon Glass } 43623b6386SSimon Glass 44623b6386SSimon Glass static int soft_spi_sda(struct udevice *dev, int bit) 45623b6386SSimon Glass { 46623b6386SSimon Glass struct soft_spi_platdata *plat = dev->platdata; 47623b6386SSimon Glass 48*050fb909SSimon Glass dm_gpio_set_value(&plat->mosi, bit); 49623b6386SSimon Glass 50623b6386SSimon Glass return 0; 51623b6386SSimon Glass } 52623b6386SSimon Glass 53623b6386SSimon Glass static int soft_spi_cs_activate(struct udevice *dev) 54623b6386SSimon Glass { 55623b6386SSimon Glass struct soft_spi_platdata *plat = dev->platdata; 56623b6386SSimon Glass 57*050fb909SSimon Glass dm_gpio_set_value(&plat->cs, 0); 58*050fb909SSimon Glass dm_gpio_set_value(&plat->sclk, 0); 59*050fb909SSimon Glass dm_gpio_set_value(&plat->cs, 1); 60623b6386SSimon Glass 61623b6386SSimon Glass return 0; 62623b6386SSimon Glass } 63623b6386SSimon Glass 64623b6386SSimon Glass static int soft_spi_cs_deactivate(struct udevice *dev) 65623b6386SSimon Glass { 66623b6386SSimon Glass struct soft_spi_platdata *plat = dev->platdata; 67623b6386SSimon Glass 68*050fb909SSimon Glass dm_gpio_set_value(&plat->cs, 0); 69623b6386SSimon Glass 70623b6386SSimon Glass return 0; 71623b6386SSimon Glass } 72623b6386SSimon Glass 73623b6386SSimon Glass static int soft_spi_claim_bus(struct udevice *dev) 74623b6386SSimon Glass { 75623b6386SSimon Glass /* 76623b6386SSimon Glass * Make sure the SPI clock is in idle state as defined for 77623b6386SSimon Glass * this slave. 78623b6386SSimon Glass */ 79623b6386SSimon Glass return soft_spi_scl(dev, 0); 80623b6386SSimon Glass } 81623b6386SSimon Glass 82623b6386SSimon Glass static int soft_spi_release_bus(struct udevice *dev) 83623b6386SSimon Glass { 84623b6386SSimon Glass /* Nothing to do */ 85623b6386SSimon Glass return 0; 86623b6386SSimon Glass } 87623b6386SSimon Glass 88623b6386SSimon Glass /*----------------------------------------------------------------------- 89623b6386SSimon Glass * SPI transfer 90623b6386SSimon Glass * 91623b6386SSimon Glass * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks 92623b6386SSimon Glass * "bitlen" bits in the SPI MISO port. That's just the way SPI works. 93623b6386SSimon Glass * 94623b6386SSimon Glass * The source of the outgoing bits is the "dout" parameter and the 95623b6386SSimon Glass * destination of the input bits is the "din" parameter. Note that "dout" 96623b6386SSimon Glass * and "din" can point to the same memory location, in which case the 97623b6386SSimon Glass * input data overwrites the output data (since both are buffered by 98623b6386SSimon Glass * temporary variables, this is OK). 99623b6386SSimon Glass */ 100623b6386SSimon Glass static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen, 101623b6386SSimon Glass const void *dout, void *din, unsigned long flags) 102623b6386SSimon Glass { 103623b6386SSimon Glass struct soft_spi_priv *priv = dev_get_priv(dev); 104623b6386SSimon Glass struct soft_spi_platdata *plat = dev->platdata; 105623b6386SSimon Glass uchar tmpdin = 0; 106623b6386SSimon Glass uchar tmpdout = 0; 107623b6386SSimon Glass const u8 *txd = dout; 108623b6386SSimon Glass u8 *rxd = din; 109623b6386SSimon Glass int cpha = priv->mode & SPI_CPHA; 110623b6386SSimon Glass unsigned int j; 111623b6386SSimon Glass 112623b6386SSimon Glass debug("spi_xfer: slave %s:%s dout %08X din %08X bitlen %u\n", 113623b6386SSimon Glass dev->parent->name, dev->name, *(uint *)txd, *(uint *)rxd, 114623b6386SSimon Glass bitlen); 115623b6386SSimon Glass 116623b6386SSimon Glass if (flags & SPI_XFER_BEGIN) 117623b6386SSimon Glass soft_spi_cs_activate(dev); 118623b6386SSimon Glass 119623b6386SSimon Glass for (j = 0; j < bitlen; j++) { 120623b6386SSimon Glass /* 121623b6386SSimon Glass * Check if it is time to work on a new byte. 122623b6386SSimon Glass */ 123623b6386SSimon Glass if ((j % 8) == 0) { 124623b6386SSimon Glass if (txd) 125623b6386SSimon Glass tmpdout = *txd++; 126623b6386SSimon Glass else 127623b6386SSimon Glass tmpdout = 0; 128623b6386SSimon Glass if (j != 0) { 129623b6386SSimon Glass if (rxd) 130623b6386SSimon Glass *rxd++ = tmpdin; 131623b6386SSimon Glass } 132623b6386SSimon Glass tmpdin = 0; 133623b6386SSimon Glass } 134623b6386SSimon Glass 135623b6386SSimon Glass if (!cpha) 136*050fb909SSimon Glass soft_spi_scl(dev, 0); 137623b6386SSimon Glass soft_spi_sda(dev, tmpdout & 0x80); 138623b6386SSimon Glass udelay(plat->spi_delay_us); 139623b6386SSimon Glass if (cpha) 140*050fb909SSimon Glass soft_spi_scl(dev, 0); 141623b6386SSimon Glass else 142*050fb909SSimon Glass soft_spi_scl(dev, 1); 143623b6386SSimon Glass tmpdin <<= 1; 144*050fb909SSimon Glass tmpdin |= dm_gpio_get_value(&plat->miso); 145623b6386SSimon Glass tmpdout <<= 1; 146623b6386SSimon Glass udelay(plat->spi_delay_us); 147623b6386SSimon Glass if (cpha) 148*050fb909SSimon Glass soft_spi_scl(dev, 1); 149623b6386SSimon Glass } 150623b6386SSimon Glass /* 151623b6386SSimon Glass * If the number of bits isn't a multiple of 8, shift the last 152623b6386SSimon Glass * bits over to left-justify them. Then store the last byte 153623b6386SSimon Glass * read in. 154623b6386SSimon Glass */ 155623b6386SSimon Glass if (rxd) { 156623b6386SSimon Glass if ((bitlen % 8) != 0) 157623b6386SSimon Glass tmpdin <<= 8 - (bitlen % 8); 158623b6386SSimon Glass *rxd++ = tmpdin; 159623b6386SSimon Glass } 160623b6386SSimon Glass 161623b6386SSimon Glass if (flags & SPI_XFER_END) 162623b6386SSimon Glass soft_spi_cs_deactivate(dev); 163623b6386SSimon Glass 164623b6386SSimon Glass return 0; 165623b6386SSimon Glass } 166623b6386SSimon Glass 167623b6386SSimon Glass static int soft_spi_set_speed(struct udevice *dev, unsigned int speed) 168623b6386SSimon Glass { 169623b6386SSimon Glass /* Accept any speed */ 170623b6386SSimon Glass return 0; 171623b6386SSimon Glass } 172623b6386SSimon Glass 173623b6386SSimon Glass static int soft_spi_set_mode(struct udevice *dev, unsigned int mode) 174623b6386SSimon Glass { 175623b6386SSimon Glass struct soft_spi_priv *priv = dev_get_priv(dev); 176623b6386SSimon Glass 177623b6386SSimon Glass priv->mode = mode; 178623b6386SSimon Glass 179623b6386SSimon Glass return 0; 180623b6386SSimon Glass } 181623b6386SSimon Glass 182623b6386SSimon Glass static int soft_spi_child_pre_probe(struct udevice *dev) 183623b6386SSimon Glass { 184623b6386SSimon Glass struct spi_slave *slave = dev_get_parentdata(dev); 185623b6386SSimon Glass 186623b6386SSimon Glass slave->dev = dev; 187623b6386SSimon Glass return spi_ofdata_to_platdata(gd->fdt_blob, dev->of_offset, slave); 188623b6386SSimon Glass } 189623b6386SSimon Glass 190623b6386SSimon Glass static const struct dm_spi_ops soft_spi_ops = { 191623b6386SSimon Glass .claim_bus = soft_spi_claim_bus, 192623b6386SSimon Glass .release_bus = soft_spi_release_bus, 193623b6386SSimon Glass .xfer = soft_spi_xfer, 194623b6386SSimon Glass .set_speed = soft_spi_set_speed, 195623b6386SSimon Glass .set_mode = soft_spi_set_mode, 196623b6386SSimon Glass }; 197623b6386SSimon Glass 198623b6386SSimon Glass static int soft_spi_ofdata_to_platdata(struct udevice *dev) 199623b6386SSimon Glass { 200623b6386SSimon Glass struct soft_spi_platdata *plat = dev->platdata; 201623b6386SSimon Glass const void *blob = gd->fdt_blob; 202623b6386SSimon Glass int node = dev->of_offset; 203623b6386SSimon Glass 204623b6386SSimon Glass plat->spi_delay_us = fdtdec_get_int(blob, node, "spi-delay-us", 0); 205623b6386SSimon Glass 206623b6386SSimon Glass return 0; 207623b6386SSimon Glass } 208623b6386SSimon Glass 209623b6386SSimon Glass static int soft_spi_probe(struct udevice *dev) 210623b6386SSimon Glass { 211623b6386SSimon Glass struct spi_slave *slave = dev_get_parentdata(dev); 212623b6386SSimon Glass struct soft_spi_platdata *plat = dev->platdata; 213*050fb909SSimon Glass int cs_flags, clk_flags; 214623b6386SSimon Glass 215*050fb909SSimon Glass cs_flags = (slave->mode & SPI_CS_HIGH) ? 0 : GPIOD_ACTIVE_LOW; 216*050fb909SSimon Glass clk_flags = (slave->mode & SPI_CPOL) ? GPIOD_ACTIVE_LOW : 0; 217*050fb909SSimon Glass if (gpio_request_by_name(dev, "cs-gpio", 0, &plat->cs, 218*050fb909SSimon Glass GPIOD_IS_OUT | cs_flags) || 219*050fb909SSimon Glass gpio_request_by_name(dev, "sclk-gpio", 0, &plat->sclk, 220*050fb909SSimon Glass GPIOD_IS_OUT | clk_flags) || 221*050fb909SSimon Glass gpio_request_by_name(dev, "mosi-gpio", 0, &plat->mosi, 222*050fb909SSimon Glass GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE) || 223*050fb909SSimon Glass gpio_request_by_name(dev, "miso-gpio", 0, &plat->miso, 224*050fb909SSimon Glass GPIOD_IS_IN)) 225*050fb909SSimon Glass return -EINVAL; 226623b6386SSimon Glass 227623b6386SSimon Glass return 0; 228623b6386SSimon Glass } 229623b6386SSimon Glass 230623b6386SSimon Glass static const struct udevice_id soft_spi_ids[] = { 231623b6386SSimon Glass { .compatible = "u-boot,soft-spi" }, 232623b6386SSimon Glass { } 233623b6386SSimon Glass }; 234623b6386SSimon Glass 235623b6386SSimon Glass U_BOOT_DRIVER(soft_spi) = { 236623b6386SSimon Glass .name = "soft_spi", 237623b6386SSimon Glass .id = UCLASS_SPI, 238623b6386SSimon Glass .of_match = soft_spi_ids, 239623b6386SSimon Glass .ops = &soft_spi_ops, 240623b6386SSimon Glass .ofdata_to_platdata = soft_spi_ofdata_to_platdata, 241623b6386SSimon Glass .platdata_auto_alloc_size = sizeof(struct soft_spi_platdata), 242623b6386SSimon Glass .priv_auto_alloc_size = sizeof(struct soft_spi_priv), 243623b6386SSimon Glass .per_child_auto_alloc_size = sizeof(struct spi_slave), 244623b6386SSimon Glass .probe = soft_spi_probe, 245623b6386SSimon Glass .child_pre_probe = soft_spi_child_pre_probe, 246623b6386SSimon Glass }; 247