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author | 2023-02-21 18:24:12 -0800 | |
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committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /drivers/spi/spi-sifive.c | |
download | linux-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.c | 487 |
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"); |