Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 770 insertions, 0 deletions

diff --git a/drivers/spi/spi-ep93xx.c b/drivers/spi/spi-ep93xx.c
new file mode 100644
index 000000000..5896a7b2f
--- /dev/null
+++ b/drivers/spi/spi-ep93xx.c
@@ -0,0 +1,770 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for Cirrus Logic EP93xx SPI controller.
+ *
+ * Copyright (C) 2010-2011 Mika Westerberg
+ *
+ * Explicit FIFO handling code was inspired by amba-pl022 driver.
+ *
+ * Chip select support using other than built-in GPIOs by H. Hartley Sweeten.
+ *
+ * For more information about the SPI controller see documentation on Cirrus
+ * Logic web site:
+ *     https://www.cirrus.com/en/pubs/manual/EP93xx_Users_Guide_UM1.pdf
+ */
+
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dmaengine.h>
+#include <linux/bitops.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/scatterlist.h>
+#include <linux/spi/spi.h>
+
+#include <linux/platform_data/dma-ep93xx.h>
+#include <linux/platform_data/spi-ep93xx.h>
+
+#define SSPCR0			0x0000
+#define SSPCR0_SPO		BIT(6)
+#define SSPCR0_SPH		BIT(7)
+#define SSPCR0_SCR_SHIFT	8
+
+#define SSPCR1			0x0004
+#define SSPCR1_RIE		BIT(0)
+#define SSPCR1_TIE		BIT(1)
+#define SSPCR1_RORIE		BIT(2)
+#define SSPCR1_LBM		BIT(3)
+#define SSPCR1_SSE		BIT(4)
+#define SSPCR1_MS		BIT(5)
+#define SSPCR1_SOD		BIT(6)
+
+#define SSPDR			0x0008
+
+#define SSPSR			0x000c
+#define SSPSR_TFE		BIT(0)
+#define SSPSR_TNF		BIT(1)
+#define SSPSR_RNE		BIT(2)
+#define SSPSR_RFF		BIT(3)
+#define SSPSR_BSY		BIT(4)
+#define SSPCPSR			0x0010
+
+#define SSPIIR			0x0014
+#define SSPIIR_RIS		BIT(0)
+#define SSPIIR_TIS		BIT(1)
+#define SSPIIR_RORIS		BIT(2)
+#define SSPICR			SSPIIR
+
+/* timeout in milliseconds */
+#define SPI_TIMEOUT		5
+/* maximum depth of RX/TX FIFO */
+#define SPI_FIFO_SIZE		8
+
+/**
+ * struct ep93xx_spi - EP93xx SPI controller structure
+ * @clk: clock for the controller
+ * @mmio: pointer to ioremap()'d registers
+ * @sspdr_phys: physical address of the SSPDR register
+ * @tx: current byte in transfer to transmit
+ * @rx: current byte in transfer to receive
+ * @fifo_level: how full is FIFO (%0..%SPI_FIFO_SIZE - %1). Receiving one
+ *              frame decreases this level and sending one frame increases it.
+ * @dma_rx: RX DMA channel
+ * @dma_tx: TX DMA channel
+ * @dma_rx_data: RX parameters passed to the DMA engine
+ * @dma_tx_data: TX parameters passed to the DMA engine
+ * @rx_sgt: sg table for RX transfers
+ * @tx_sgt: sg table for TX transfers
+ * @zeropage: dummy page used as RX buffer when only TX buffer is passed in by
+ *            the client
+ */
+struct ep93xx_spi {
+	struct clk			*clk;
+	void __iomem			*mmio;
+	unsigned long			sspdr_phys;
+	size_t				tx;
+	size_t				rx;
+	size_t				fifo_level;
+	struct dma_chan			*dma_rx;
+	struct dma_chan			*dma_tx;
+	struct ep93xx_dma_data		dma_rx_data;
+	struct ep93xx_dma_data		dma_tx_data;
+	struct sg_table			rx_sgt;
+	struct sg_table			tx_sgt;
+	void				*zeropage;
+};
+
+/* converts bits per word to CR0.DSS value */
+#define bits_per_word_to_dss(bpw)	((bpw) - 1)
+
+/**
+ * ep93xx_spi_calc_divisors() - calculates SPI clock divisors
+ * @master: SPI master
+ * @rate: desired SPI output clock rate
+ * @div_cpsr: pointer to return the cpsr (pre-scaler) divider
+ * @div_scr: pointer to return the scr divider
+ */
+static int ep93xx_spi_calc_divisors(struct spi_master *master,
+				    u32 rate, u8 *div_cpsr, u8 *div_scr)
+{
+	struct ep93xx_spi *espi = spi_master_get_devdata(master);
+	unsigned long spi_clk_rate = clk_get_rate(espi->clk);
+	int cpsr, scr;
+
+	/*
+	 * Make sure that max value is between values supported by the
+	 * controller.
+	 */
+	rate = clamp(rate, master->min_speed_hz, master->max_speed_hz);
+
+	/*
+	 * Calculate divisors so that we can get speed according the
+	 * following formula:
+	 *	rate = spi_clock_rate / (cpsr * (1 + scr))
+	 *
+	 * cpsr must be even number and starts from 2, scr can be any number
+	 * between 0 and 255.
+	 */
+	for (cpsr = 2; cpsr <= 254; cpsr += 2) {
+		for (scr = 0; scr <= 255; scr++) {
+			if ((spi_clk_rate / (cpsr * (scr + 1))) <= rate) {
+				*div_scr = (u8)scr;
+				*div_cpsr = (u8)cpsr;
+				return 0;
+			}
+		}
+	}
+
+	return -EINVAL;
+}
+
+static int ep93xx_spi_chip_setup(struct spi_master *master,
+				 struct spi_device *spi,
+				 struct spi_transfer *xfer)
+{
+	struct ep93xx_spi *espi = spi_master_get_devdata(master);
+	u8 dss = bits_per_word_to_dss(xfer->bits_per_word);
+	u8 div_cpsr = 0;
+	u8 div_scr = 0;
+	u16 cr0;
+	int err;
+
+	err = ep93xx_spi_calc_divisors(master, xfer->speed_hz,
+				       &div_cpsr, &div_scr);
+	if (err)
+		return err;
+
+	cr0 = div_scr << SSPCR0_SCR_SHIFT;
+	if (spi->mode & SPI_CPOL)
+		cr0 |= SSPCR0_SPO;
+	if (spi->mode & SPI_CPHA)
+		cr0 |= SSPCR0_SPH;
+	cr0 |= dss;
+
+	dev_dbg(&master->dev, "setup: mode %d, cpsr %d, scr %d, dss %d\n",
+		spi->mode, div_cpsr, div_scr, dss);
+	dev_dbg(&master->dev, "setup: cr0 %#x\n", cr0);
+
+	writel(div_cpsr, espi->mmio + SSPCPSR);
+	writel(cr0, espi->mmio + SSPCR0);
+
+	return 0;
+}
+
+static void ep93xx_do_write(struct spi_master *master)
+{
+	struct ep93xx_spi *espi = spi_master_get_devdata(master);
+	struct spi_transfer *xfer = master->cur_msg->state;
+	u32 val = 0;
+
+	if (xfer->bits_per_word > 8) {
+		if (xfer->tx_buf)
+			val = ((u16 *)xfer->tx_buf)[espi->tx];
+		espi->tx += 2;
+	} else {
+		if (xfer->tx_buf)
+			val = ((u8 *)xfer->tx_buf)[espi->tx];
+		espi->tx += 1;
+	}
+	writel(val, espi->mmio + SSPDR);
+}
+
+static void ep93xx_do_read(struct spi_master *master)
+{
+	struct ep93xx_spi *espi = spi_master_get_devdata(master);
+	struct spi_transfer *xfer = master->cur_msg->state;
+	u32 val;
+
+	val = readl(espi->mmio + SSPDR);
+	if (xfer->bits_per_word > 8) {
+		if (xfer->rx_buf)
+			((u16 *)xfer->rx_buf)[espi->rx] = val;
+		espi->rx += 2;
+	} else {
+		if (xfer->rx_buf)
+			((u8 *)xfer->rx_buf)[espi->rx] = val;
+		espi->rx += 1;
+	}
+}
+
+/**
+ * ep93xx_spi_read_write() - perform next RX/TX transfer
+ * @master: SPI master
+ *
+ * This function transfers next bytes (or half-words) to/from RX/TX FIFOs. If
+ * called several times, the whole transfer will be completed. Returns
+ * %-EINPROGRESS when current transfer was not yet completed otherwise %0.
+ *
+ * When this function is finished, RX FIFO should be empty and TX FIFO should be
+ * full.
+ */
+static int ep93xx_spi_read_write(struct spi_master *master)
+{
+	struct ep93xx_spi *espi = spi_master_get_devdata(master);
+	struct spi_transfer *xfer = master->cur_msg->state;
+
+	/* read as long as RX FIFO has frames in it */
+	while ((readl(espi->mmio + SSPSR) & SSPSR_RNE)) {
+		ep93xx_do_read(master);
+		espi->fifo_level--;
+	}
+
+	/* write as long as TX FIFO has room */
+	while (espi->fifo_level < SPI_FIFO_SIZE && espi->tx < xfer->len) {
+		ep93xx_do_write(master);
+		espi->fifo_level++;
+	}
+
+	if (espi->rx == xfer->len)
+		return 0;
+
+	return -EINPROGRESS;
+}
+
+static enum dma_transfer_direction
+ep93xx_dma_data_to_trans_dir(enum dma_data_direction dir)
+{
+	switch (dir) {
+	case DMA_TO_DEVICE:
+		return DMA_MEM_TO_DEV;
+	case DMA_FROM_DEVICE:
+		return DMA_DEV_TO_MEM;
+	default:
+		return DMA_TRANS_NONE;
+	}
+}
+
+/**
+ * ep93xx_spi_dma_prepare() - prepares a DMA transfer
+ * @master: SPI master
+ * @dir: DMA transfer direction
+ *
+ * Function configures the DMA, maps the buffer and prepares the DMA
+ * descriptor. Returns a valid DMA descriptor in case of success and ERR_PTR
+ * in case of failure.
+ */
+static struct dma_async_tx_descriptor *
+ep93xx_spi_dma_prepare(struct spi_master *master,
+		       enum dma_data_direction dir)
+{
+	struct ep93xx_spi *espi = spi_master_get_devdata(master);
+	struct spi_transfer *xfer = master->cur_msg->state;
+	struct dma_async_tx_descriptor *txd;
+	enum dma_slave_buswidth buswidth;
+	struct dma_slave_config conf;
+	struct scatterlist *sg;
+	struct sg_table *sgt;
+	struct dma_chan *chan;
+	const void *buf, *pbuf;
+	size_t len = xfer->len;
+	int i, ret, nents;
+
+	if (xfer->bits_per_word > 8)
+		buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
+	else
+		buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
+
+	memset(&conf, 0, sizeof(conf));
+	conf.direction = ep93xx_dma_data_to_trans_dir(dir);
+
+	if (dir == DMA_FROM_DEVICE) {
+		chan = espi->dma_rx;
+		buf = xfer->rx_buf;
+		sgt = &espi->rx_sgt;
+
+		conf.src_addr = espi->sspdr_phys;
+		conf.src_addr_width = buswidth;
+	} else {
+		chan = espi->dma_tx;
+		buf = xfer->tx_buf;
+		sgt = &espi->tx_sgt;
+
+		conf.dst_addr = espi->sspdr_phys;
+		conf.dst_addr_width = buswidth;
+	}
+
+	ret = dmaengine_slave_config(chan, &conf);
+	if (ret)
+		return ERR_PTR(ret);
+
+	/*
+	 * We need to split the transfer into PAGE_SIZE'd chunks. This is
+	 * because we are using @espi->zeropage to provide a zero RX buffer
+	 * for the TX transfers and we have only allocated one page for that.
+	 *
+	 * For performance reasons we allocate a new sg_table only when
+	 * needed. Otherwise we will re-use the current one. Eventually the
+	 * last sg_table is released in ep93xx_spi_release_dma().
+	 */
+
+	nents = DIV_ROUND_UP(len, PAGE_SIZE);
+	if (nents != sgt->nents) {
+		sg_free_table(sgt);
+
+		ret = sg_alloc_table(sgt, nents, GFP_KERNEL);
+		if (ret)
+			return ERR_PTR(ret);
+	}
+
+	pbuf = buf;
+	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
+		size_t bytes = min_t(size_t, len, PAGE_SIZE);
+
+		if (buf) {
+			sg_set_page(sg, virt_to_page(pbuf), bytes,
+				    offset_in_page(pbuf));
+		} else {
+			sg_set_page(sg, virt_to_page(espi->zeropage),
+				    bytes, 0);
+		}
+
+		pbuf += bytes;
+		len -= bytes;
+	}
+
+	if (WARN_ON(len)) {
+		dev_warn(&master->dev, "len = %zu expected 0!\n", len);
+		return ERR_PTR(-EINVAL);
+	}
+
+	nents = dma_map_sg(chan->device->dev, sgt->sgl, sgt->nents, dir);
+	if (!nents)
+		return ERR_PTR(-ENOMEM);
+
+	txd = dmaengine_prep_slave_sg(chan, sgt->sgl, nents, conf.direction,
+				      DMA_CTRL_ACK);
+	if (!txd) {
+		dma_unmap_sg(chan->device->dev, sgt->sgl, sgt->nents, dir);
+		return ERR_PTR(-ENOMEM);
+	}
+	return txd;
+}
+
+/**
+ * ep93xx_spi_dma_finish() - finishes with a DMA transfer
+ * @master: SPI master
+ * @dir: DMA transfer direction
+ *
+ * Function finishes with the DMA transfer. After this, the DMA buffer is
+ * unmapped.
+ */
+static void ep93xx_spi_dma_finish(struct spi_master *master,
+				  enum dma_data_direction dir)
+{
+	struct ep93xx_spi *espi = spi_master_get_devdata(master);
+	struct dma_chan *chan;
+	struct sg_table *sgt;
+
+	if (dir == DMA_FROM_DEVICE) {
+		chan = espi->dma_rx;
+		sgt = &espi->rx_sgt;
+	} else {
+		chan = espi->dma_tx;
+		sgt = &espi->tx_sgt;
+	}
+
+	dma_unmap_sg(chan->device->dev, sgt->sgl, sgt->nents, dir);
+}
+
+static void ep93xx_spi_dma_callback(void *callback_param)
+{
+	struct spi_master *master = callback_param;
+
+	ep93xx_spi_dma_finish(master, DMA_TO_DEVICE);
+	ep93xx_spi_dma_finish(master, DMA_FROM_DEVICE);
+
+	spi_finalize_current_transfer(master);
+}
+
+static int ep93xx_spi_dma_transfer(struct spi_master *master)
+{
+	struct ep93xx_spi *espi = spi_master_get_devdata(master);
+	struct dma_async_tx_descriptor *rxd, *txd;
+
+	rxd = ep93xx_spi_dma_prepare(master, DMA_FROM_DEVICE);
+	if (IS_ERR(rxd)) {
+		dev_err(&master->dev, "DMA RX failed: %ld\n", PTR_ERR(rxd));
+		return PTR_ERR(rxd);
+	}
+
+	txd = ep93xx_spi_dma_prepare(master, DMA_TO_DEVICE);
+	if (IS_ERR(txd)) {
+		ep93xx_spi_dma_finish(master, DMA_FROM_DEVICE);
+		dev_err(&master->dev, "DMA TX failed: %ld\n", PTR_ERR(txd));
+		return PTR_ERR(txd);
+	}
+
+	/* We are ready when RX is done */
+	rxd->callback = ep93xx_spi_dma_callback;
+	rxd->callback_param = master;
+
+	/* Now submit both descriptors and start DMA */
+	dmaengine_submit(rxd);
+	dmaengine_submit(txd);
+
+	dma_async_issue_pending(espi->dma_rx);
+	dma_async_issue_pending(espi->dma_tx);
+
+	/* signal that we need to wait for completion */
+	return 1;
+}
+
+static irqreturn_t ep93xx_spi_interrupt(int irq, void *dev_id)
+{
+	struct spi_master *master = dev_id;
+	struct ep93xx_spi *espi = spi_master_get_devdata(master);
+	u32 val;
+
+	/*
+	 * If we got ROR (receive overrun) interrupt we know that something is
+	 * wrong. Just abort the message.
+	 */
+	if (readl(espi->mmio + SSPIIR) & SSPIIR_RORIS) {
+		/* clear the overrun interrupt */
+		writel(0, espi->mmio + SSPICR);
+		dev_warn(&master->dev,
+			 "receive overrun, aborting the message\n");
+		master->cur_msg->status = -EIO;
+	} else {
+		/*
+		 * Interrupt is either RX (RIS) or TX (TIS). For both cases we
+		 * simply execute next data transfer.
+		 */
+		if (ep93xx_spi_read_write(master)) {
+			/*
+			 * In normal case, there still is some processing left
+			 * for current transfer. Let's wait for the next
+			 * interrupt then.
+			 */
+			return IRQ_HANDLED;
+		}
+	}
+
+	/*
+	 * Current transfer is finished, either with error or with success. In
+	 * any case we disable interrupts and notify the worker to handle
+	 * any post-processing of the message.
+	 */
+	val = readl(espi->mmio + SSPCR1);
+	val &= ~(SSPCR1_RORIE | SSPCR1_TIE | SSPCR1_RIE);
+	writel(val, espi->mmio + SSPCR1);
+
+	spi_finalize_current_transfer(master);
+
+	return IRQ_HANDLED;
+}
+
+static int ep93xx_spi_transfer_one(struct spi_master *master,
+				   struct spi_device *spi,
+				   struct spi_transfer *xfer)
+{
+	struct ep93xx_spi *espi = spi_master_get_devdata(master);
+	u32 val;
+	int ret;
+
+	ret = ep93xx_spi_chip_setup(master, spi, xfer);
+	if (ret) {
+		dev_err(&master->dev, "failed to setup chip for transfer\n");
+		return ret;
+	}
+
+	master->cur_msg->state = xfer;
+	espi->rx = 0;
+	espi->tx = 0;
+
+	/*
+	 * There is no point of setting up DMA for the transfers which will
+	 * fit into the FIFO and can be transferred with a single interrupt.
+	 * So in these cases we will be using PIO and don't bother for DMA.
+	 */
+	if (espi->dma_rx && xfer->len > SPI_FIFO_SIZE)
+		return ep93xx_spi_dma_transfer(master);
+
+	/* Using PIO so prime the TX FIFO and enable interrupts */
+	ep93xx_spi_read_write(master);
+
+	val = readl(espi->mmio + SSPCR1);
+	val |= (SSPCR1_RORIE | SSPCR1_TIE | SSPCR1_RIE);
+	writel(val, espi->mmio + SSPCR1);
+
+	/* signal that we need to wait for completion */
+	return 1;
+}
+
+static int ep93xx_spi_prepare_message(struct spi_master *master,
+				      struct spi_message *msg)
+{
+	struct ep93xx_spi *espi = spi_master_get_devdata(master);
+	unsigned long timeout;
+
+	/*
+	 * Just to be sure: flush any data from RX FIFO.
+	 */
+	timeout = jiffies + msecs_to_jiffies(SPI_TIMEOUT);
+	while (readl(espi->mmio + SSPSR) & SSPSR_RNE) {
+		if (time_after(jiffies, timeout)) {
+			dev_warn(&master->dev,
+				 "timeout while flushing RX FIFO\n");
+			return -ETIMEDOUT;
+		}
+		readl(espi->mmio + SSPDR);
+	}
+
+	/*
+	 * We explicitly handle FIFO level. This way we don't have to check TX
+	 * FIFO status using %SSPSR_TNF bit which may cause RX FIFO overruns.
+	 */
+	espi->fifo_level = 0;
+
+	return 0;
+}
+
+static int ep93xx_spi_prepare_hardware(struct spi_master *master)
+{
+	struct ep93xx_spi *espi = spi_master_get_devdata(master);
+	u32 val;
+	int ret;
+
+	ret = clk_prepare_enable(espi->clk);
+	if (ret)
+		return ret;
+
+	val = readl(espi->mmio + SSPCR1);
+	val |= SSPCR1_SSE;
+	writel(val, espi->mmio + SSPCR1);
+
+	return 0;
+}
+
+static int ep93xx_spi_unprepare_hardware(struct spi_master *master)
+{
+	struct ep93xx_spi *espi = spi_master_get_devdata(master);
+	u32 val;
+
+	val = readl(espi->mmio + SSPCR1);
+	val &= ~SSPCR1_SSE;
+	writel(val, espi->mmio + SSPCR1);
+
+	clk_disable_unprepare(espi->clk);
+
+	return 0;
+}
+
+static bool ep93xx_spi_dma_filter(struct dma_chan *chan, void *filter_param)
+{
+	if (ep93xx_dma_chan_is_m2p(chan))
+		return false;
+
+	chan->private = filter_param;
+	return true;
+}
+
+static int ep93xx_spi_setup_dma(struct ep93xx_spi *espi)
+{
+	dma_cap_mask_t mask;
+	int ret;
+
+	espi->zeropage = (void *)get_zeroed_page(GFP_KERNEL);
+	if (!espi->zeropage)
+		return -ENOMEM;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	espi->dma_rx_data.port = EP93XX_DMA_SSP;
+	espi->dma_rx_data.direction = DMA_DEV_TO_MEM;
+	espi->dma_rx_data.name = "ep93xx-spi-rx";
+
+	espi->dma_rx = dma_request_channel(mask, ep93xx_spi_dma_filter,
+					   &espi->dma_rx_data);
+	if (!espi->dma_rx) {
+		ret = -ENODEV;
+		goto fail_free_page;
+	}
+
+	espi->dma_tx_data.port = EP93XX_DMA_SSP;
+	espi->dma_tx_data.direction = DMA_MEM_TO_DEV;
+	espi->dma_tx_data.name = "ep93xx-spi-tx";
+
+	espi->dma_tx = dma_request_channel(mask, ep93xx_spi_dma_filter,
+					   &espi->dma_tx_data);
+	if (!espi->dma_tx) {
+		ret = -ENODEV;
+		goto fail_release_rx;
+	}
+
+	return 0;
+
+fail_release_rx:
+	dma_release_channel(espi->dma_rx);
+	espi->dma_rx = NULL;
+fail_free_page:
+	free_page((unsigned long)espi->zeropage);
+
+	return ret;
+}
+
+static void ep93xx_spi_release_dma(struct ep93xx_spi *espi)
+{
+	if (espi->dma_rx) {
+		dma_release_channel(espi->dma_rx);
+		sg_free_table(&espi->rx_sgt);
+	}
+	if (espi->dma_tx) {
+		dma_release_channel(espi->dma_tx);
+		sg_free_table(&espi->tx_sgt);
+	}
+
+	if (espi->zeropage)
+		free_page((unsigned long)espi->zeropage);
+}
+
+static int ep93xx_spi_probe(struct platform_device *pdev)
+{
+	struct spi_master *master;
+	struct ep93xx_spi_info *info;
+	struct ep93xx_spi *espi;
+	struct resource *res;
+	int irq;
+	int error;
+
+	info = dev_get_platdata(&pdev->dev);
+	if (!info) {
+		dev_err(&pdev->dev, "missing platform data\n");
+		return -EINVAL;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return -EBUSY;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "unable to get iomem resource\n");
+		return -ENODEV;
+	}
+
+	master = spi_alloc_master(&pdev->dev, sizeof(*espi));
+	if (!master)
+		return -ENOMEM;
+
+	master->use_gpio_descriptors = true;
+	master->prepare_transfer_hardware = ep93xx_spi_prepare_hardware;
+	master->unprepare_transfer_hardware = ep93xx_spi_unprepare_hardware;
+	master->prepare_message = ep93xx_spi_prepare_message;
+	master->transfer_one = ep93xx_spi_transfer_one;
+	master->bus_num = pdev->id;
+	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
+	/*
+	 * The SPI core will count the number of GPIO descriptors to figure
+	 * out the number of chip selects available on the platform.
+	 */
+	master->num_chipselect = 0;
+
+	platform_set_drvdata(pdev, master);
+
+	espi = spi_master_get_devdata(master);
+
+	espi->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(espi->clk)) {
+		dev_err(&pdev->dev, "unable to get spi clock\n");
+		error = PTR_ERR(espi->clk);
+		goto fail_release_master;
+	}
+
+	/*
+	 * Calculate maximum and minimum supported clock rates
+	 * for the controller.
+	 */
+	master->max_speed_hz = clk_get_rate(espi->clk) / 2;
+	master->min_speed_hz = clk_get_rate(espi->clk) / (254 * 256);
+
+	espi->sspdr_phys = res->start + SSPDR;
+
+	espi->mmio = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(espi->mmio)) {
+		error = PTR_ERR(espi->mmio);
+		goto fail_release_master;
+	}
+
+	error = devm_request_irq(&pdev->dev, irq, ep93xx_spi_interrupt,
+				0, "ep93xx-spi", master);
+	if (error) {
+		dev_err(&pdev->dev, "failed to request irq\n");
+		goto fail_release_master;
+	}
+
+	if (info->use_dma && ep93xx_spi_setup_dma(espi))
+		dev_warn(&pdev->dev, "DMA setup failed. Falling back to PIO\n");
+
+	/* make sure that the hardware is disabled */
+	writel(0, espi->mmio + SSPCR1);
+
+	error = devm_spi_register_master(&pdev->dev, master);
+	if (error) {
+		dev_err(&pdev->dev, "failed to register SPI master\n");
+		goto fail_free_dma;
+	}
+
+	dev_info(&pdev->dev, "EP93xx SPI Controller at 0x%08lx irq %d\n",
+		 (unsigned long)res->start, irq);
+
+	return 0;
+
+fail_free_dma:
+	ep93xx_spi_release_dma(espi);
+fail_release_master:
+	spi_master_put(master);
+
+	return error;
+}
+
+static int ep93xx_spi_remove(struct platform_device *pdev)
+{
+	struct spi_master *master = platform_get_drvdata(pdev);
+	struct ep93xx_spi *espi = spi_master_get_devdata(master);
+
+	ep93xx_spi_release_dma(espi);
+
+	return 0;
+}
+
+static struct platform_driver ep93xx_spi_driver = {
+	.driver		= {
+		.name	= "ep93xx-spi",
+	},
+	.probe		= ep93xx_spi_probe,
+	.remove		= ep93xx_spi_remove,
+};
+module_platform_driver(ep93xx_spi_driver);
+
+MODULE_DESCRIPTION("EP93xx SPI Controller driver");
+MODULE_AUTHOR("Mika Westerberg <mika.westerberg@iki.fi>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:ep93xx-spi");