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https://github.com/AsahiLinux/u-boot
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0fd3d91152
Most drivers use these access methods but a few do not. Update them. In some cases the access is not permitted, so mark those with a FIXME tag for the maintainer to check. Signed-off-by: Simon Glass <sjg@chromium.org> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Pratyush Yadav <p.yadav@ti.com>
287 lines
6.6 KiB
C
287 lines
6.6 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (c) 2014 Google, Inc
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*
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* (C) Copyright 2002
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* Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
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*
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* Influenced by code from:
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* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
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*/
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#include <common.h>
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#include <dm.h>
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#include <errno.h>
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#include <fdtdec.h>
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#include <log.h>
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#include <malloc.h>
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#include <spi.h>
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#include <asm/gpio.h>
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#include <linux/bitops.h>
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#include <linux/delay.h>
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DECLARE_GLOBAL_DATA_PTR;
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struct soft_spi_plat {
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struct gpio_desc cs;
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struct gpio_desc sclk;
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struct gpio_desc mosi;
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struct gpio_desc miso;
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int spi_delay_us;
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int flags;
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};
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#define SPI_MASTER_NO_RX BIT(0)
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#define SPI_MASTER_NO_TX BIT(1)
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struct soft_spi_priv {
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unsigned int mode;
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};
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static int soft_spi_scl(struct udevice *dev, int bit)
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{
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struct udevice *bus = dev_get_parent(dev);
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struct soft_spi_plat *plat = dev_get_plat(bus);
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dm_gpio_set_value(&plat->sclk, bit);
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return 0;
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}
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static int soft_spi_sda(struct udevice *dev, int bit)
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{
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struct udevice *bus = dev_get_parent(dev);
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struct soft_spi_plat *plat = dev_get_plat(bus);
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dm_gpio_set_value(&plat->mosi, bit);
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return 0;
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}
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static int soft_spi_cs_activate(struct udevice *dev)
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{
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struct udevice *bus = dev_get_parent(dev);
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struct soft_spi_priv *priv = dev_get_priv(bus);
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struct soft_spi_plat *plat = dev_get_plat(bus);
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int cidle = !!(priv->mode & SPI_CPOL);
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dm_gpio_set_value(&plat->cs, 0);
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dm_gpio_set_value(&plat->sclk, cidle); /* to idle */
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dm_gpio_set_value(&plat->cs, 1);
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return 0;
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}
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static int soft_spi_cs_deactivate(struct udevice *dev)
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{
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struct udevice *bus = dev_get_parent(dev);
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struct soft_spi_plat *plat = dev_get_plat(bus);
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dm_gpio_set_value(&plat->cs, 0);
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return 0;
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}
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static int soft_spi_claim_bus(struct udevice *dev)
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{
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struct udevice *bus = dev_get_parent(dev);
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struct soft_spi_priv *priv = dev_get_priv(bus);
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int cidle = !!(priv->mode & SPI_CPOL);
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/*
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* Make sure the SPI clock is in idle state as defined for
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* this slave.
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*/
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return soft_spi_scl(dev, cidle);
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}
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static int soft_spi_release_bus(struct udevice *dev)
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{
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/* Nothing to do */
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return 0;
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}
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/*-----------------------------------------------------------------------
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* SPI transfer
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*
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* This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
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* "bitlen" bits in the SPI MISO port. That's just the way SPI works.
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*
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* The source of the outgoing bits is the "dout" parameter and the
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* destination of the input bits is the "din" parameter. Note that "dout"
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* and "din" can point to the same memory location, in which case the
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* input data overwrites the output data (since both are buffered by
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* temporary variables, this is OK).
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*/
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static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen,
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const void *dout, void *din, unsigned long flags)
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{
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struct udevice *bus = dev_get_parent(dev);
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struct soft_spi_priv *priv = dev_get_priv(bus);
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struct soft_spi_plat *plat = dev_get_plat(bus);
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uchar tmpdin = 0;
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uchar tmpdout = 0;
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const u8 *txd = dout;
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u8 *rxd = din;
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int cpha = !!(priv->mode & SPI_CPHA);
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int cidle = !!(priv->mode & SPI_CPOL);
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unsigned int j;
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debug("spi_xfer: slave %s:%s dout %08X din %08X bitlen %u\n",
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dev->parent->name, dev->name, *(uint *)txd, *(uint *)rxd,
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bitlen);
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if (flags & SPI_XFER_BEGIN)
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soft_spi_cs_activate(dev);
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for (j = 0; j < bitlen; j++) {
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/*
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* Check if it is time to work on a new byte.
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*/
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if ((j % 8) == 0) {
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if (txd)
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tmpdout = *txd++;
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else
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tmpdout = 0;
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if (j != 0) {
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if (rxd)
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*rxd++ = tmpdin;
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}
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tmpdin = 0;
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}
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/*
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* CPOL 0: idle is low (0), active is high (1)
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* CPOL 1: idle is high (1), active is low (0)
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*/
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/*
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* drive bit
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* CPHA 1: CLK from idle to active
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*/
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if (cpha)
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soft_spi_scl(dev, !cidle);
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if ((plat->flags & SPI_MASTER_NO_TX) == 0)
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soft_spi_sda(dev, !!(tmpdout & 0x80));
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udelay(plat->spi_delay_us);
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/*
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* sample bit
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* CPHA 0: CLK from idle to active
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* CPHA 1: CLK from active to idle
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*/
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if (!cpha)
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soft_spi_scl(dev, !cidle);
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else
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soft_spi_scl(dev, cidle);
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tmpdin <<= 1;
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if ((plat->flags & SPI_MASTER_NO_RX) == 0)
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tmpdin |= dm_gpio_get_value(&plat->miso);
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tmpdout <<= 1;
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udelay(plat->spi_delay_us);
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/*
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* drive bit
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* CPHA 0: CLK from active to idle
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*/
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if (!cpha)
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soft_spi_scl(dev, cidle);
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}
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/*
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* If the number of bits isn't a multiple of 8, shift the last
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* bits over to left-justify them. Then store the last byte
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* read in.
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*/
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if (rxd) {
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if ((bitlen % 8) != 0)
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tmpdin <<= 8 - (bitlen % 8);
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*rxd++ = tmpdin;
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}
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if (flags & SPI_XFER_END)
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soft_spi_cs_deactivate(dev);
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return 0;
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}
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static int soft_spi_set_speed(struct udevice *dev, unsigned int speed)
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{
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/* Ignore any speed settings. Speed is implemented via "spi-delay-us" */
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return 0;
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}
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static int soft_spi_set_mode(struct udevice *dev, unsigned int mode)
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{
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struct soft_spi_priv *priv = dev_get_priv(dev);
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priv->mode = mode;
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return 0;
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}
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static const struct dm_spi_ops soft_spi_ops = {
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.claim_bus = soft_spi_claim_bus,
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.release_bus = soft_spi_release_bus,
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.xfer = soft_spi_xfer,
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.set_speed = soft_spi_set_speed,
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.set_mode = soft_spi_set_mode,
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};
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static int soft_spi_of_to_plat(struct udevice *dev)
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{
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struct soft_spi_plat *plat = dev_get_plat(dev);
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const void *blob = gd->fdt_blob;
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int node = dev_of_offset(dev);
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plat->spi_delay_us = fdtdec_get_int(blob, node, "spi-delay-us", 0);
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return 0;
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}
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static int soft_spi_probe(struct udevice *dev)
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{
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struct spi_slave *slave = dev_get_parent_priv(dev);
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struct soft_spi_plat *plat = dev_get_plat(dev);
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int cs_flags, clk_flags;
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int ret;
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cs_flags = (slave && slave->mode & SPI_CS_HIGH) ? 0 : GPIOD_ACTIVE_LOW;
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clk_flags = (slave && slave->mode & SPI_CPOL) ? GPIOD_ACTIVE_LOW : 0;
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if (gpio_request_by_name(dev, "cs-gpios", 0, &plat->cs,
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GPIOD_IS_OUT | cs_flags) ||
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gpio_request_by_name(dev, "gpio-sck", 0, &plat->sclk,
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GPIOD_IS_OUT | clk_flags))
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return -EINVAL;
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ret = gpio_request_by_name(dev, "gpio-mosi", 0, &plat->mosi,
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GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE);
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if (ret)
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plat->flags |= SPI_MASTER_NO_TX;
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ret = gpio_request_by_name(dev, "gpio-miso", 0, &plat->miso,
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GPIOD_IS_IN);
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if (ret)
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plat->flags |= SPI_MASTER_NO_RX;
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if ((plat->flags & (SPI_MASTER_NO_RX | SPI_MASTER_NO_TX)) ==
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(SPI_MASTER_NO_RX | SPI_MASTER_NO_TX))
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return -EINVAL;
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return 0;
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}
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static const struct udevice_id soft_spi_ids[] = {
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{ .compatible = "spi-gpio" },
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{ }
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};
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U_BOOT_DRIVER(soft_spi) = {
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.name = "soft_spi",
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.id = UCLASS_SPI,
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.of_match = soft_spi_ids,
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.ops = &soft_spi_ops,
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.of_to_plat = soft_spi_of_to_plat,
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.plat_auto = sizeof(struct soft_spi_plat),
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.priv_auto = sizeof(struct soft_spi_priv),
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.probe = soft_spi_probe,
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};
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