/*
   * Copyright (c) 2014 Google, Inc
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  #include <common.h>
  #include <dm.h>
  #include <errno.h>
  #include <fdtdec.h>
  #include <malloc.h>
  #include <spi.h>
  #include <dm/device-internal.h>
  #include <dm/uclass-internal.h>
  #include <dm/root.h>
  #include <dm/lists.h>
  #include <dm/util.h>
  
  DECLARE_GLOBAL_DATA_PTR;
  
  static int spi_set_speed_mode(struct udevice *bus, int speed, int mode)
  {
  	struct dm_spi_ops *ops;
  	int ret;
  
  	ops = spi_get_ops(bus);
  	if (ops->set_speed)
  		ret = ops->set_speed(bus, speed);
  	else
  		ret = -EINVAL;
  	if (ret) {
  		printf("Cannot set speed (err=%d)
  ", ret);
  		return ret;
  	}
  
  	if (ops->set_mode)
  		ret = ops->set_mode(bus, mode);
  	else
  		ret = -EINVAL;
  	if (ret) {
  		printf("Cannot set mode (err=%d)
  ", ret);
  		return ret;
  	}
  
  	return 0;
  }
  
  int spi_claim_bus(struct spi_slave *slave)
  {
  	struct udevice *dev = slave->dev;
  	struct udevice *bus = dev->parent;
  	struct dm_spi_ops *ops = spi_get_ops(bus);
  	struct dm_spi_bus *spi = bus->uclass_priv;
  	int speed;
  	int ret;
  
  	speed = slave->max_hz;
  	if (spi->max_hz) {
  		if (speed)
  			speed = min(speed, (int)spi->max_hz);
  		else
  			speed = spi->max_hz;
  	}
  	if (!speed)
  		speed = 100000;
  	ret = spi_set_speed_mode(bus, speed, slave->mode);
  	if (ret)
  		return ret;
  
  	return ops->claim_bus ? ops->claim_bus(bus) : 0;
  }
  
  void spi_release_bus(struct spi_slave *slave)
  {
  	struct udevice *dev = slave->dev;
  	struct udevice *bus = dev->parent;
  	struct dm_spi_ops *ops = spi_get_ops(bus);
  
  	if (ops->release_bus)
  		ops->release_bus(bus);
  }
  
  int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
  	     const void *dout, void *din, unsigned long flags)
  {
  	struct udevice *dev = slave->dev;
  	struct udevice *bus = dev->parent;
  
  	if (bus->uclass->uc_drv->id != UCLASS_SPI)
  		return -EOPNOTSUPP;
  
  	return spi_get_ops(bus)->xfer(dev, bitlen, dout, din, flags);
  }
  
  int spi_post_bind(struct udevice *dev)
  {
  	/* Scan the bus for devices */
  	return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false);
  }
  
  int spi_child_post_bind(struct udevice *dev)
  {
  	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
  
  	if (dev->of_offset == -1)
  		return 0;
  
  	return spi_slave_ofdata_to_platdata(gd->fdt_blob, dev->of_offset, plat);
  }
  
  int spi_post_probe(struct udevice *bus)
  {
  	struct dm_spi_bus *spi = bus->uclass_priv;
  
  	spi->max_hz = fdtdec_get_int(gd->fdt_blob, bus->of_offset,
  				     "spi-max-frequency", 0);
  
  	return 0;
  }
  
  int spi_child_pre_probe(struct udevice *dev)
  {
  	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
  	struct spi_slave *slave = dev_get_parentdata(dev);
  
  	/*
  	 * This is needed because we pass struct spi_slave around the place
  	 * instead slave->dev (a struct udevice). So we have to have some
  	 * way to access the slave udevice given struct spi_slave. Once we
  	 * change the SPI API to use udevice instead of spi_slave, we can
  	 * drop this.
  	 */
  	slave->dev = dev;
  
  	slave->max_hz = plat->max_hz;
  	slave->mode = plat->mode;
  
  	return 0;
  }
  
  int spi_chip_select(struct udevice *dev)
  {
  	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
  
  	return plat ? plat->cs : -ENOENT;
  }
  
  int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp)
  {
  	struct udevice *dev;
  
  	for (device_find_first_child(bus, &dev); dev;
  	     device_find_next_child(&dev)) {
  		struct dm_spi_slave_platdata *plat;
  
  		plat = dev_get_parent_platdata(dev);
  		debug("%s: plat=%p, cs=%d
  ", __func__, plat, plat->cs);
  		if (plat->cs == cs) {
  			*devp = dev;
  			return 0;
  		}
  	}
  
  	return -ENODEV;
  }
  
  int spi_cs_is_valid(unsigned int busnum, unsigned int cs)
  {
  	struct spi_cs_info info;
  	struct udevice *bus;
  	int ret;
  
  	ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus);
  	if (ret) {
  		debug("%s: No bus %d
  ", __func__, busnum);
  		return ret;
  	}
  
  	return spi_cs_info(bus, cs, &info);
  }
  
  int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info)
  {
  	struct spi_cs_info local_info;
  	struct dm_spi_ops *ops;
  	int ret;
  
  	if (!info)
  		info = &local_info;
  
  	/* If there is a device attached, return it */
  	info->dev = NULL;
  	ret = spi_find_chip_select(bus, cs, &info->dev);
  	if (!ret)
  		return 0;
  
  	/*
  	 * Otherwise ask the driver. For the moment we don't have CS info.
  	 * When we do we could provide the driver with a helper function
  	 * to figure out what chip selects are valid, or just handle the
  	 * request.
  	 */
  	ops = spi_get_ops(bus);
  	if (ops->cs_info)
  		return ops->cs_info(bus, cs, info);
  
  	/*
  	 * We could assume there is at least one valid chip select, but best
  	 * to be sure and return an error in this case. The driver didn't
  	 * care enough to tell us.
  	 */
  	return -ENODEV;
  }
  
  int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,
  			struct udevice **devp)
  {
  	struct udevice *bus, *dev;
  	int ret;
  
  	ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus);
  	if (ret) {
  		debug("%s: No bus %d
  ", __func__, busnum);
  		return ret;
  	}
  	ret = spi_find_chip_select(bus, cs, &dev);
  	if (ret) {
  		debug("%s: No cs %d
  ", __func__, cs);
  		return ret;
  	}
  	*busp = bus;
  	*devp = dev;
  
  	return ret;
  }
  
  int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
  		       const char *drv_name, const char *dev_name,
  		       struct udevice **busp, struct spi_slave **devp)
  {
  	struct udevice *bus, *dev;
  	bool created = false;
  	int ret;
  
  	ret = uclass_get_device_by_seq(UCLASS_SPI, busnum, &bus);
  	if (ret) {
  		printf("Invalid bus %d (err=%d)
  ", busnum, ret);
  		return ret;
  	}
  	ret = spi_find_chip_select(bus, cs, &dev);
  
  	/*
  	 * If there is no such device, create one automatically. This means
  	 * that we don't need a device tree node or platform data for the
  	 * SPI flash chip - we will bind to the correct driver.
  	 */
  	if (ret == -ENODEV && drv_name) {
  		struct dm_spi_slave_platdata *plat;
  
  		debug("%s: Binding new device '%s', busnum=%d, cs=%d, driver=%s
  ",
  		      __func__, dev_name, busnum, cs, drv_name);
  		ret = device_bind_driver(bus, drv_name, dev_name, &dev);
  		if (ret)
  			return ret;
  		plat = dev_get_parent_platdata(dev);
  		plat->cs = cs;
  		plat->max_hz = speed;
  		plat->mode = mode;
  		created = true;
  	} else if (ret) {
  		printf("Invalid chip select %d:%d (err=%d)
  ", busnum, cs,
  		       ret);
  		return ret;
  	}
  
  	if (!device_active(dev)) {
  		struct spi_slave *slave;
  
  		ret = device_probe(dev);
  		if (ret)
  			goto err;
  		slave = dev_get_parentdata(dev);
  		slave->dev = dev;
  	}
  
  	ret = spi_set_speed_mode(bus, speed, mode);
  	if (ret)
  		goto err;
  
  	*busp = bus;
  	*devp = dev_get_parentdata(dev);
  	debug("%s: bus=%p, slave=%p
  ", __func__, bus, *devp);
  
  	return 0;
  
  err:
  	debug("%s: Error path, credted=%d, device '%s'
  ", __func__,
  	      created, dev->name);
  	if (created) {
  		device_remove(dev);
  		device_unbind(dev);
  	}
  
  	return ret;
  }
  
  /* Compatibility function - to be removed */
  struct spi_slave *spi_setup_slave_fdt(const void *blob, int node,
  				      int bus_node)
  {
  	struct udevice *bus, *dev;
  	int ret;
  
  	ret = uclass_get_device_by_of_offset(UCLASS_SPI, bus_node, &bus);
  	if (ret)
  		return NULL;
  	ret = device_get_child_by_of_offset(bus, node, &dev);
  	if (ret)
  		return NULL;
  	return dev_get_parentdata(dev);
  }
  
  /* Compatibility function - to be removed */
  struct spi_slave *spi_setup_slave(unsigned int busnum, unsigned int cs,
  				  unsigned int speed, unsigned int mode)
  {
  	struct spi_slave *slave;
  	struct udevice *dev;
  	int ret;
  
  	ret = spi_get_bus_and_cs(busnum, cs, speed, mode, NULL, 0, &dev,
  				  &slave);
  	if (ret)
  		return NULL;
  
  	return slave;
  }
  
  void spi_free_slave(struct spi_slave *slave)
  {
  	device_remove(slave->dev);
  	slave->dev = NULL;
  }
  
  int spi_slave_ofdata_to_platdata(const void *blob, int node,
  				 struct dm_spi_slave_platdata *plat)
  {
  	int mode = 0;
  
  	plat->cs = fdtdec_get_int(blob, node, "reg", -1);
  	plat->max_hz = fdtdec_get_int(blob, node, "spi-max-frequency", 0);
  	if (fdtdec_get_bool(blob, node, "spi-cpol"))
  		mode |= SPI_CPOL;
  	if (fdtdec_get_bool(blob, node, "spi-cpha"))
  		mode |= SPI_CPHA;
  	if (fdtdec_get_bool(blob, node, "spi-cs-high"))
  		mode |= SPI_CS_HIGH;
  	if (fdtdec_get_bool(blob, node, "spi-half-duplex"))
  		mode |= SPI_PREAMBLE;
  	plat->mode = mode;
  
  	return 0;
  }
  
  UCLASS_DRIVER(spi) = {
  	.id		= UCLASS_SPI,
  	.name		= "spi",
  	.flags		= DM_UC_FLAG_SEQ_ALIAS,
  	.post_bind	= spi_post_bind,
  	.post_probe	= spi_post_probe,
  	.child_pre_probe = spi_child_pre_probe,
  	.per_device_auto_alloc_size = sizeof(struct dm_spi_bus),
  	.per_child_auto_alloc_size = sizeof(struct spi_slave),
  	.per_child_platdata_auto_alloc_size =
  			sizeof(struct dm_spi_slave_platdata),
  	.child_post_bind = spi_child_post_bind,
  };
  
  UCLASS_DRIVER(spi_generic) = {
  	.id		= UCLASS_SPI_GENERIC,
  	.name		= "spi_generic",
  };
  
  U_BOOT_DRIVER(spi_generic_drv) = {
  	.name		= "spi_generic_drv",
  	.id		= UCLASS_SPI_GENERIC,
  };