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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /drivers/spi/spi-sifive.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
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(). ...
Diffstat (limited to 'drivers/spi/spi-sifive.c')
-rw-r--r--drivers/spi/spi-sifive.c487
1 files changed, 487 insertions, 0 deletions
diff --git a/drivers/spi/spi-sifive.c b/drivers/spi/spi-sifive.c
new file mode 100644
index 000000000..e29e85cee
--- /dev/null
+++ b/drivers/spi/spi-sifive.c
@@ -0,0 +1,487 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright 2018 SiFive, Inc.
+//
+// SiFive SPI controller driver (master mode only)
+//
+// Author: SiFive, Inc.
+// sifive@sifive.com
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/io.h>
+#include <linux/log2.h>
+
+#define SIFIVE_SPI_DRIVER_NAME "sifive_spi"
+
+#define SIFIVE_SPI_MAX_CS 32
+#define SIFIVE_SPI_DEFAULT_DEPTH 8
+#define SIFIVE_SPI_DEFAULT_MAX_BITS 8
+
+/* register offsets */
+#define SIFIVE_SPI_REG_SCKDIV 0x00 /* Serial clock divisor */
+#define SIFIVE_SPI_REG_SCKMODE 0x04 /* Serial clock mode */
+#define SIFIVE_SPI_REG_CSID 0x10 /* Chip select ID */
+#define SIFIVE_SPI_REG_CSDEF 0x14 /* Chip select default */
+#define SIFIVE_SPI_REG_CSMODE 0x18 /* Chip select mode */
+#define SIFIVE_SPI_REG_DELAY0 0x28 /* Delay control 0 */
+#define SIFIVE_SPI_REG_DELAY1 0x2c /* Delay control 1 */
+#define SIFIVE_SPI_REG_FMT 0x40 /* Frame format */
+#define SIFIVE_SPI_REG_TXDATA 0x48 /* Tx FIFO data */
+#define SIFIVE_SPI_REG_RXDATA 0x4c /* Rx FIFO data */
+#define SIFIVE_SPI_REG_TXMARK 0x50 /* Tx FIFO watermark */
+#define SIFIVE_SPI_REG_RXMARK 0x54 /* Rx FIFO watermark */
+#define SIFIVE_SPI_REG_FCTRL 0x60 /* SPI flash interface control */
+#define SIFIVE_SPI_REG_FFMT 0x64 /* SPI flash instruction format */
+#define SIFIVE_SPI_REG_IE 0x70 /* Interrupt Enable Register */
+#define SIFIVE_SPI_REG_IP 0x74 /* Interrupt Pendings Register */
+
+/* sckdiv bits */
+#define SIFIVE_SPI_SCKDIV_DIV_MASK 0xfffU
+
+/* sckmode bits */
+#define SIFIVE_SPI_SCKMODE_PHA BIT(0)
+#define SIFIVE_SPI_SCKMODE_POL BIT(1)
+#define SIFIVE_SPI_SCKMODE_MODE_MASK (SIFIVE_SPI_SCKMODE_PHA | \
+ SIFIVE_SPI_SCKMODE_POL)
+
+/* csmode bits */
+#define SIFIVE_SPI_CSMODE_MODE_AUTO 0U
+#define SIFIVE_SPI_CSMODE_MODE_HOLD 2U
+#define SIFIVE_SPI_CSMODE_MODE_OFF 3U
+
+/* delay0 bits */
+#define SIFIVE_SPI_DELAY0_CSSCK(x) ((u32)(x))
+#define SIFIVE_SPI_DELAY0_CSSCK_MASK 0xffU
+#define SIFIVE_SPI_DELAY0_SCKCS(x) ((u32)(x) << 16)
+#define SIFIVE_SPI_DELAY0_SCKCS_MASK (0xffU << 16)
+
+/* delay1 bits */
+#define SIFIVE_SPI_DELAY1_INTERCS(x) ((u32)(x))
+#define SIFIVE_SPI_DELAY1_INTERCS_MASK 0xffU
+#define SIFIVE_SPI_DELAY1_INTERXFR(x) ((u32)(x) << 16)
+#define SIFIVE_SPI_DELAY1_INTERXFR_MASK (0xffU << 16)
+
+/* fmt bits */
+#define SIFIVE_SPI_FMT_PROTO_SINGLE 0U
+#define SIFIVE_SPI_FMT_PROTO_DUAL 1U
+#define SIFIVE_SPI_FMT_PROTO_QUAD 2U
+#define SIFIVE_SPI_FMT_PROTO_MASK 3U
+#define SIFIVE_SPI_FMT_ENDIAN BIT(2)
+#define SIFIVE_SPI_FMT_DIR BIT(3)
+#define SIFIVE_SPI_FMT_LEN(x) ((u32)(x) << 16)
+#define SIFIVE_SPI_FMT_LEN_MASK (0xfU << 16)
+
+/* txdata bits */
+#define SIFIVE_SPI_TXDATA_DATA_MASK 0xffU
+#define SIFIVE_SPI_TXDATA_FULL BIT(31)
+
+/* rxdata bits */
+#define SIFIVE_SPI_RXDATA_DATA_MASK 0xffU
+#define SIFIVE_SPI_RXDATA_EMPTY BIT(31)
+
+/* ie and ip bits */
+#define SIFIVE_SPI_IP_TXWM BIT(0)
+#define SIFIVE_SPI_IP_RXWM BIT(1)
+
+struct sifive_spi {
+ void __iomem *regs; /* virt. address of control registers */
+ struct clk *clk; /* bus clock */
+ unsigned int fifo_depth; /* fifo depth in words */
+ u32 cs_inactive; /* level of the CS pins when inactive */
+ struct completion done; /* wake-up from interrupt */
+};
+
+static void sifive_spi_write(struct sifive_spi *spi, int offset, u32 value)
+{
+ iowrite32(value, spi->regs + offset);
+}
+
+static u32 sifive_spi_read(struct sifive_spi *spi, int offset)
+{
+ return ioread32(spi->regs + offset);
+}
+
+static void sifive_spi_init(struct sifive_spi *spi)
+{
+ /* Watermark interrupts are disabled by default */
+ sifive_spi_write(spi, SIFIVE_SPI_REG_IE, 0);
+
+ /* Default watermark FIFO threshold values */
+ sifive_spi_write(spi, SIFIVE_SPI_REG_TXMARK, 1);
+ sifive_spi_write(spi, SIFIVE_SPI_REG_RXMARK, 0);
+
+ /* Set CS/SCK Delays and Inactive Time to defaults */
+ sifive_spi_write(spi, SIFIVE_SPI_REG_DELAY0,
+ SIFIVE_SPI_DELAY0_CSSCK(1) |
+ SIFIVE_SPI_DELAY0_SCKCS(1));
+ sifive_spi_write(spi, SIFIVE_SPI_REG_DELAY1,
+ SIFIVE_SPI_DELAY1_INTERCS(1) |
+ SIFIVE_SPI_DELAY1_INTERXFR(0));
+
+ /* Exit specialized memory-mapped SPI flash mode */
+ sifive_spi_write(spi, SIFIVE_SPI_REG_FCTRL, 0);
+}
+
+static int
+sifive_spi_prepare_message(struct spi_master *master, struct spi_message *msg)
+{
+ struct sifive_spi *spi = spi_master_get_devdata(master);
+ struct spi_device *device = msg->spi;
+
+ /* Update the chip select polarity */
+ if (device->mode & SPI_CS_HIGH)
+ spi->cs_inactive &= ~BIT(device->chip_select);
+ else
+ spi->cs_inactive |= BIT(device->chip_select);
+ sifive_spi_write(spi, SIFIVE_SPI_REG_CSDEF, spi->cs_inactive);
+
+ /* Select the correct device */
+ sifive_spi_write(spi, SIFIVE_SPI_REG_CSID, device->chip_select);
+
+ /* Set clock mode */
+ sifive_spi_write(spi, SIFIVE_SPI_REG_SCKMODE,
+ device->mode & SIFIVE_SPI_SCKMODE_MODE_MASK);
+
+ return 0;
+}
+
+static void sifive_spi_set_cs(struct spi_device *device, bool is_high)
+{
+ struct sifive_spi *spi = spi_master_get_devdata(device->master);
+
+ /* Reverse polarity is handled by SCMR/CPOL. Not inverted CS. */
+ if (device->mode & SPI_CS_HIGH)
+ is_high = !is_high;
+
+ sifive_spi_write(spi, SIFIVE_SPI_REG_CSMODE, is_high ?
+ SIFIVE_SPI_CSMODE_MODE_AUTO :
+ SIFIVE_SPI_CSMODE_MODE_HOLD);
+}
+
+static int
+sifive_spi_prep_transfer(struct sifive_spi *spi, struct spi_device *device,
+ struct spi_transfer *t)
+{
+ u32 cr;
+ unsigned int mode;
+
+ /* Calculate and program the clock rate */
+ cr = DIV_ROUND_UP(clk_get_rate(spi->clk) >> 1, t->speed_hz) - 1;
+ cr &= SIFIVE_SPI_SCKDIV_DIV_MASK;
+ sifive_spi_write(spi, SIFIVE_SPI_REG_SCKDIV, cr);
+
+ mode = max_t(unsigned int, t->rx_nbits, t->tx_nbits);
+
+ /* Set frame format */
+ cr = SIFIVE_SPI_FMT_LEN(t->bits_per_word);
+ switch (mode) {
+ case SPI_NBITS_QUAD:
+ cr |= SIFIVE_SPI_FMT_PROTO_QUAD;
+ break;
+ case SPI_NBITS_DUAL:
+ cr |= SIFIVE_SPI_FMT_PROTO_DUAL;
+ break;
+ default:
+ cr |= SIFIVE_SPI_FMT_PROTO_SINGLE;
+ break;
+ }
+ if (device->mode & SPI_LSB_FIRST)
+ cr |= SIFIVE_SPI_FMT_ENDIAN;
+ if (!t->rx_buf)
+ cr |= SIFIVE_SPI_FMT_DIR;
+ sifive_spi_write(spi, SIFIVE_SPI_REG_FMT, cr);
+
+ /* We will want to poll if the time we need to wait is
+ * less than the context switching time.
+ * Let's call that threshold 5us. The operation will take:
+ * (8/mode) * fifo_depth / hz <= 5 * 10^-6
+ * 1600000 * fifo_depth <= hz * mode
+ */
+ return 1600000 * spi->fifo_depth <= t->speed_hz * mode;
+}
+
+static irqreturn_t sifive_spi_irq(int irq, void *dev_id)
+{
+ struct sifive_spi *spi = dev_id;
+ u32 ip = sifive_spi_read(spi, SIFIVE_SPI_REG_IP);
+
+ if (ip & (SIFIVE_SPI_IP_TXWM | SIFIVE_SPI_IP_RXWM)) {
+ /* Disable interrupts until next transfer */
+ sifive_spi_write(spi, SIFIVE_SPI_REG_IE, 0);
+ complete(&spi->done);
+ return IRQ_HANDLED;
+ }
+
+ return IRQ_NONE;
+}
+
+static void sifive_spi_wait(struct sifive_spi *spi, u32 bit, int poll)
+{
+ if (poll) {
+ u32 cr;
+
+ do {
+ cr = sifive_spi_read(spi, SIFIVE_SPI_REG_IP);
+ } while (!(cr & bit));
+ } else {
+ reinit_completion(&spi->done);
+ sifive_spi_write(spi, SIFIVE_SPI_REG_IE, bit);
+ wait_for_completion(&spi->done);
+ }
+}
+
+static void sifive_spi_tx(struct sifive_spi *spi, const u8 *tx_ptr)
+{
+ WARN_ON_ONCE((sifive_spi_read(spi, SIFIVE_SPI_REG_TXDATA)
+ & SIFIVE_SPI_TXDATA_FULL) != 0);
+ sifive_spi_write(spi, SIFIVE_SPI_REG_TXDATA,
+ *tx_ptr & SIFIVE_SPI_TXDATA_DATA_MASK);
+}
+
+static void sifive_spi_rx(struct sifive_spi *spi, u8 *rx_ptr)
+{
+ u32 data = sifive_spi_read(spi, SIFIVE_SPI_REG_RXDATA);
+
+ WARN_ON_ONCE((data & SIFIVE_SPI_RXDATA_EMPTY) != 0);
+ *rx_ptr = data & SIFIVE_SPI_RXDATA_DATA_MASK;
+}
+
+static int
+sifive_spi_transfer_one(struct spi_master *master, struct spi_device *device,
+ struct spi_transfer *t)
+{
+ struct sifive_spi *spi = spi_master_get_devdata(master);
+ int poll = sifive_spi_prep_transfer(spi, device, t);
+ const u8 *tx_ptr = t->tx_buf;
+ u8 *rx_ptr = t->rx_buf;
+ unsigned int remaining_words = t->len;
+
+ while (remaining_words) {
+ unsigned int n_words = min(remaining_words, spi->fifo_depth);
+ unsigned int i;
+
+ /* Enqueue n_words for transmission */
+ for (i = 0; i < n_words; i++)
+ sifive_spi_tx(spi, tx_ptr++);
+
+ if (rx_ptr) {
+ /* Wait for transmission + reception to complete */
+ sifive_spi_write(spi, SIFIVE_SPI_REG_RXMARK,
+ n_words - 1);
+ sifive_spi_wait(spi, SIFIVE_SPI_IP_RXWM, poll);
+
+ /* Read out all the data from the RX FIFO */
+ for (i = 0; i < n_words; i++)
+ sifive_spi_rx(spi, rx_ptr++);
+ } else {
+ /* Wait for transmission to complete */
+ sifive_spi_wait(spi, SIFIVE_SPI_IP_TXWM, poll);
+ }
+
+ remaining_words -= n_words;
+ }
+
+ return 0;
+}
+
+static int sifive_spi_probe(struct platform_device *pdev)
+{
+ struct sifive_spi *spi;
+ int ret, irq, num_cs;
+ u32 cs_bits, max_bits_per_word;
+ struct spi_master *master;
+
+ master = spi_alloc_master(&pdev->dev, sizeof(struct sifive_spi));
+ if (!master) {
+ dev_err(&pdev->dev, "out of memory\n");
+ return -ENOMEM;
+ }
+
+ spi = spi_master_get_devdata(master);
+ init_completion(&spi->done);
+ platform_set_drvdata(pdev, master);
+
+ spi->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(spi->regs)) {
+ ret = PTR_ERR(spi->regs);
+ goto put_master;
+ }
+
+ spi->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(spi->clk)) {
+ dev_err(&pdev->dev, "Unable to find bus clock\n");
+ ret = PTR_ERR(spi->clk);
+ goto put_master;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ ret = irq;
+ goto put_master;
+ }
+
+ /* Optional parameters */
+ ret =
+ of_property_read_u32(pdev->dev.of_node, "sifive,fifo-depth",
+ &spi->fifo_depth);
+ if (ret < 0)
+ spi->fifo_depth = SIFIVE_SPI_DEFAULT_DEPTH;
+
+ ret =
+ of_property_read_u32(pdev->dev.of_node, "sifive,max-bits-per-word",
+ &max_bits_per_word);
+
+ if (!ret && max_bits_per_word < 8) {
+ dev_err(&pdev->dev, "Only 8bit SPI words supported by the driver\n");
+ ret = -EINVAL;
+ goto put_master;
+ }
+
+ /* Spin up the bus clock before hitting registers */
+ ret = clk_prepare_enable(spi->clk);
+ if (ret) {
+ dev_err(&pdev->dev, "Unable to enable bus clock\n");
+ goto put_master;
+ }
+
+ /* probe the number of CS lines */
+ spi->cs_inactive = sifive_spi_read(spi, SIFIVE_SPI_REG_CSDEF);
+ sifive_spi_write(spi, SIFIVE_SPI_REG_CSDEF, 0xffffffffU);
+ cs_bits = sifive_spi_read(spi, SIFIVE_SPI_REG_CSDEF);
+ sifive_spi_write(spi, SIFIVE_SPI_REG_CSDEF, spi->cs_inactive);
+ if (!cs_bits) {
+ dev_err(&pdev->dev, "Could not auto probe CS lines\n");
+ ret = -EINVAL;
+ goto disable_clk;
+ }
+
+ num_cs = ilog2(cs_bits) + 1;
+ if (num_cs > SIFIVE_SPI_MAX_CS) {
+ dev_err(&pdev->dev, "Invalid number of spi slaves\n");
+ ret = -EINVAL;
+ goto disable_clk;
+ }
+
+ /* Define our master */
+ master->dev.of_node = pdev->dev.of_node;
+ master->bus_num = pdev->id;
+ master->num_chipselect = num_cs;
+ master->mode_bits = SPI_CPHA | SPI_CPOL
+ | SPI_CS_HIGH | SPI_LSB_FIRST
+ | SPI_TX_DUAL | SPI_TX_QUAD
+ | SPI_RX_DUAL | SPI_RX_QUAD;
+ /* TODO: add driver support for bits_per_word < 8
+ * we need to "left-align" the bits (unless SPI_LSB_FIRST)
+ */
+ master->bits_per_word_mask = SPI_BPW_MASK(8);
+ master->flags = SPI_CONTROLLER_MUST_TX | SPI_MASTER_GPIO_SS;
+ master->prepare_message = sifive_spi_prepare_message;
+ master->set_cs = sifive_spi_set_cs;
+ master->transfer_one = sifive_spi_transfer_one;
+
+ pdev->dev.dma_mask = NULL;
+ /* Configure the SPI master hardware */
+ sifive_spi_init(spi);
+
+ /* Register for SPI Interrupt */
+ ret = devm_request_irq(&pdev->dev, irq, sifive_spi_irq, 0,
+ dev_name(&pdev->dev), spi);
+ if (ret) {
+ dev_err(&pdev->dev, "Unable to bind to interrupt\n");
+ goto disable_clk;
+ }
+
+ dev_info(&pdev->dev, "mapped; irq=%d, cs=%d\n",
+ irq, master->num_chipselect);
+
+ ret = devm_spi_register_master(&pdev->dev, master);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "spi_register_master failed\n");
+ goto disable_clk;
+ }
+
+ return 0;
+
+disable_clk:
+ clk_disable_unprepare(spi->clk);
+put_master:
+ spi_master_put(master);
+
+ return ret;
+}
+
+static int sifive_spi_remove(struct platform_device *pdev)
+{
+ struct spi_master *master = platform_get_drvdata(pdev);
+ struct sifive_spi *spi = spi_master_get_devdata(master);
+
+ /* Disable all the interrupts just in case */
+ sifive_spi_write(spi, SIFIVE_SPI_REG_IE, 0);
+ clk_disable_unprepare(spi->clk);
+
+ return 0;
+}
+
+static int sifive_spi_suspend(struct device *dev)
+{
+ struct spi_master *master = dev_get_drvdata(dev);
+ struct sifive_spi *spi = spi_master_get_devdata(master);
+ int ret;
+
+ ret = spi_master_suspend(master);
+ if (ret)
+ return ret;
+
+ /* Disable all the interrupts just in case */
+ sifive_spi_write(spi, SIFIVE_SPI_REG_IE, 0);
+
+ clk_disable_unprepare(spi->clk);
+
+ return ret;
+}
+
+static int sifive_spi_resume(struct device *dev)
+{
+ struct spi_master *master = dev_get_drvdata(dev);
+ struct sifive_spi *spi = spi_master_get_devdata(master);
+ int ret;
+
+ ret = clk_prepare_enable(spi->clk);
+ if (ret)
+ return ret;
+ ret = spi_master_resume(master);
+ if (ret)
+ clk_disable_unprepare(spi->clk);
+
+ return ret;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(sifive_spi_pm_ops,
+ sifive_spi_suspend, sifive_spi_resume);
+
+
+static const struct of_device_id sifive_spi_of_match[] = {
+ { .compatible = "sifive,spi0", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, sifive_spi_of_match);
+
+static struct platform_driver sifive_spi_driver = {
+ .probe = sifive_spi_probe,
+ .remove = sifive_spi_remove,
+ .driver = {
+ .name = SIFIVE_SPI_DRIVER_NAME,
+ .pm = &sifive_spi_pm_ops,
+ .of_match_table = sifive_spi_of_match,
+ },
+};
+module_platform_driver(sifive_spi_driver);
+
+MODULE_AUTHOR("SiFive, Inc. <sifive@sifive.com>");
+MODULE_DESCRIPTION("SiFive SPI driver");
+MODULE_LICENSE("GPL");