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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-sun4i.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 '')
-rw-r--r-- | drivers/spi/spi-sun4i.c | 551 |
1 files changed, 551 insertions, 0 deletions
diff --git a/drivers/spi/spi-sun4i.c b/drivers/spi/spi-sun4i.c new file mode 100644 index 000000000..6000d0761 --- /dev/null +++ b/drivers/spi/spi-sun4i.c @@ -0,0 +1,551 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2012 - 2014 Allwinner Tech + * Pan Nan <pannan@allwinnertech.com> + * + * Copyright (C) 2014 Maxime Ripard + * Maxime Ripard <maxime.ripard@free-electrons.com> + */ + +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> + +#include <linux/spi/spi.h> + +#define SUN4I_FIFO_DEPTH 64 + +#define SUN4I_RXDATA_REG 0x00 + +#define SUN4I_TXDATA_REG 0x04 + +#define SUN4I_CTL_REG 0x08 +#define SUN4I_CTL_ENABLE BIT(0) +#define SUN4I_CTL_MASTER BIT(1) +#define SUN4I_CTL_CPHA BIT(2) +#define SUN4I_CTL_CPOL BIT(3) +#define SUN4I_CTL_CS_ACTIVE_LOW BIT(4) +#define SUN4I_CTL_LMTF BIT(6) +#define SUN4I_CTL_TF_RST BIT(8) +#define SUN4I_CTL_RF_RST BIT(9) +#define SUN4I_CTL_XCH BIT(10) +#define SUN4I_CTL_CS_MASK 0x3000 +#define SUN4I_CTL_CS(cs) (((cs) << 12) & SUN4I_CTL_CS_MASK) +#define SUN4I_CTL_DHB BIT(15) +#define SUN4I_CTL_CS_MANUAL BIT(16) +#define SUN4I_CTL_CS_LEVEL BIT(17) +#define SUN4I_CTL_TP BIT(18) + +#define SUN4I_INT_CTL_REG 0x0c +#define SUN4I_INT_CTL_RF_F34 BIT(4) +#define SUN4I_INT_CTL_TF_E34 BIT(12) +#define SUN4I_INT_CTL_TC BIT(16) + +#define SUN4I_INT_STA_REG 0x10 + +#define SUN4I_DMA_CTL_REG 0x14 + +#define SUN4I_WAIT_REG 0x18 + +#define SUN4I_CLK_CTL_REG 0x1c +#define SUN4I_CLK_CTL_CDR2_MASK 0xff +#define SUN4I_CLK_CTL_CDR2(div) ((div) & SUN4I_CLK_CTL_CDR2_MASK) +#define SUN4I_CLK_CTL_CDR1_MASK 0xf +#define SUN4I_CLK_CTL_CDR1(div) (((div) & SUN4I_CLK_CTL_CDR1_MASK) << 8) +#define SUN4I_CLK_CTL_DRS BIT(12) + +#define SUN4I_MAX_XFER_SIZE 0xffffff + +#define SUN4I_BURST_CNT_REG 0x20 +#define SUN4I_BURST_CNT(cnt) ((cnt) & SUN4I_MAX_XFER_SIZE) + +#define SUN4I_XMIT_CNT_REG 0x24 +#define SUN4I_XMIT_CNT(cnt) ((cnt) & SUN4I_MAX_XFER_SIZE) + + +#define SUN4I_FIFO_STA_REG 0x28 +#define SUN4I_FIFO_STA_RF_CNT_MASK 0x7f +#define SUN4I_FIFO_STA_RF_CNT_BITS 0 +#define SUN4I_FIFO_STA_TF_CNT_MASK 0x7f +#define SUN4I_FIFO_STA_TF_CNT_BITS 16 + +struct sun4i_spi { + struct spi_master *master; + void __iomem *base_addr; + struct clk *hclk; + struct clk *mclk; + + struct completion done; + + const u8 *tx_buf; + u8 *rx_buf; + int len; +}; + +static inline u32 sun4i_spi_read(struct sun4i_spi *sspi, u32 reg) +{ + return readl(sspi->base_addr + reg); +} + +static inline void sun4i_spi_write(struct sun4i_spi *sspi, u32 reg, u32 value) +{ + writel(value, sspi->base_addr + reg); +} + +static inline u32 sun4i_spi_get_tx_fifo_count(struct sun4i_spi *sspi) +{ + u32 reg = sun4i_spi_read(sspi, SUN4I_FIFO_STA_REG); + + reg >>= SUN4I_FIFO_STA_TF_CNT_BITS; + + return reg & SUN4I_FIFO_STA_TF_CNT_MASK; +} + +static inline void sun4i_spi_enable_interrupt(struct sun4i_spi *sspi, u32 mask) +{ + u32 reg = sun4i_spi_read(sspi, SUN4I_INT_CTL_REG); + + reg |= mask; + sun4i_spi_write(sspi, SUN4I_INT_CTL_REG, reg); +} + +static inline void sun4i_spi_disable_interrupt(struct sun4i_spi *sspi, u32 mask) +{ + u32 reg = sun4i_spi_read(sspi, SUN4I_INT_CTL_REG); + + reg &= ~mask; + sun4i_spi_write(sspi, SUN4I_INT_CTL_REG, reg); +} + +static inline void sun4i_spi_drain_fifo(struct sun4i_spi *sspi, int len) +{ + u32 reg, cnt; + u8 byte; + + /* See how much data is available */ + reg = sun4i_spi_read(sspi, SUN4I_FIFO_STA_REG); + reg &= SUN4I_FIFO_STA_RF_CNT_MASK; + cnt = reg >> SUN4I_FIFO_STA_RF_CNT_BITS; + + if (len > cnt) + len = cnt; + + while (len--) { + byte = readb(sspi->base_addr + SUN4I_RXDATA_REG); + if (sspi->rx_buf) + *sspi->rx_buf++ = byte; + } +} + +static inline void sun4i_spi_fill_fifo(struct sun4i_spi *sspi, int len) +{ + u32 cnt; + u8 byte; + + /* See how much data we can fit */ + cnt = SUN4I_FIFO_DEPTH - sun4i_spi_get_tx_fifo_count(sspi); + + len = min3(len, (int)cnt, sspi->len); + + while (len--) { + byte = sspi->tx_buf ? *sspi->tx_buf++ : 0; + writeb(byte, sspi->base_addr + SUN4I_TXDATA_REG); + sspi->len--; + } +} + +static void sun4i_spi_set_cs(struct spi_device *spi, bool enable) +{ + struct sun4i_spi *sspi = spi_master_get_devdata(spi->master); + u32 reg; + + reg = sun4i_spi_read(sspi, SUN4I_CTL_REG); + + reg &= ~SUN4I_CTL_CS_MASK; + reg |= SUN4I_CTL_CS(spi->chip_select); + + /* We want to control the chip select manually */ + reg |= SUN4I_CTL_CS_MANUAL; + + if (enable) + reg |= SUN4I_CTL_CS_LEVEL; + else + reg &= ~SUN4I_CTL_CS_LEVEL; + + /* + * Even though this looks irrelevant since we are supposed to + * be controlling the chip select manually, this bit also + * controls the levels of the chip select for inactive + * devices. + * + * If we don't set it, the chip select level will go low by + * default when the device is idle, which is not really + * expected in the common case where the chip select is active + * low. + */ + if (spi->mode & SPI_CS_HIGH) + reg &= ~SUN4I_CTL_CS_ACTIVE_LOW; + else + reg |= SUN4I_CTL_CS_ACTIVE_LOW; + + sun4i_spi_write(sspi, SUN4I_CTL_REG, reg); +} + +static size_t sun4i_spi_max_transfer_size(struct spi_device *spi) +{ + return SUN4I_MAX_XFER_SIZE - 1; +} + +static int sun4i_spi_transfer_one(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *tfr) +{ + struct sun4i_spi *sspi = spi_master_get_devdata(master); + unsigned int mclk_rate, div, timeout; + unsigned int start, end, tx_time; + unsigned int tx_len = 0; + int ret = 0; + u32 reg; + + /* We don't support transfer larger than the FIFO */ + if (tfr->len > SUN4I_MAX_XFER_SIZE) + return -EMSGSIZE; + + if (tfr->tx_buf && tfr->len >= SUN4I_MAX_XFER_SIZE) + return -EMSGSIZE; + + reinit_completion(&sspi->done); + sspi->tx_buf = tfr->tx_buf; + sspi->rx_buf = tfr->rx_buf; + sspi->len = tfr->len; + + /* Clear pending interrupts */ + sun4i_spi_write(sspi, SUN4I_INT_STA_REG, ~0); + + + reg = sun4i_spi_read(sspi, SUN4I_CTL_REG); + + /* Reset FIFOs */ + sun4i_spi_write(sspi, SUN4I_CTL_REG, + reg | SUN4I_CTL_RF_RST | SUN4I_CTL_TF_RST); + + /* + * Setup the transfer control register: Chip Select, + * polarities, etc. + */ + if (spi->mode & SPI_CPOL) + reg |= SUN4I_CTL_CPOL; + else + reg &= ~SUN4I_CTL_CPOL; + + if (spi->mode & SPI_CPHA) + reg |= SUN4I_CTL_CPHA; + else + reg &= ~SUN4I_CTL_CPHA; + + if (spi->mode & SPI_LSB_FIRST) + reg |= SUN4I_CTL_LMTF; + else + reg &= ~SUN4I_CTL_LMTF; + + + /* + * If it's a TX only transfer, we don't want to fill the RX + * FIFO with bogus data + */ + if (sspi->rx_buf) + reg &= ~SUN4I_CTL_DHB; + else + reg |= SUN4I_CTL_DHB; + + sun4i_spi_write(sspi, SUN4I_CTL_REG, reg); + + /* Ensure that we have a parent clock fast enough */ + mclk_rate = clk_get_rate(sspi->mclk); + if (mclk_rate < (2 * tfr->speed_hz)) { + clk_set_rate(sspi->mclk, 2 * tfr->speed_hz); + mclk_rate = clk_get_rate(sspi->mclk); + } + + /* + * Setup clock divider. + * + * We have two choices there. Either we can use the clock + * divide rate 1, which is calculated thanks to this formula: + * SPI_CLK = MOD_CLK / (2 ^ (cdr + 1)) + * Or we can use CDR2, which is calculated with the formula: + * SPI_CLK = MOD_CLK / (2 * (cdr + 1)) + * Whether we use the former or the latter is set through the + * DRS bit. + * + * First try CDR2, and if we can't reach the expected + * frequency, fall back to CDR1. + */ + div = mclk_rate / (2 * tfr->speed_hz); + if (div <= (SUN4I_CLK_CTL_CDR2_MASK + 1)) { + if (div > 0) + div--; + + reg = SUN4I_CLK_CTL_CDR2(div) | SUN4I_CLK_CTL_DRS; + } else { + div = ilog2(mclk_rate) - ilog2(tfr->speed_hz); + reg = SUN4I_CLK_CTL_CDR1(div); + } + + sun4i_spi_write(sspi, SUN4I_CLK_CTL_REG, reg); + + /* Setup the transfer now... */ + if (sspi->tx_buf) + tx_len = tfr->len; + + /* Setup the counters */ + sun4i_spi_write(sspi, SUN4I_BURST_CNT_REG, SUN4I_BURST_CNT(tfr->len)); + sun4i_spi_write(sspi, SUN4I_XMIT_CNT_REG, SUN4I_XMIT_CNT(tx_len)); + + /* + * Fill the TX FIFO + * Filling the FIFO fully causes timeout for some reason + * at least on spi2 on A10s + */ + sun4i_spi_fill_fifo(sspi, SUN4I_FIFO_DEPTH - 1); + + /* Enable the interrupts */ + sun4i_spi_enable_interrupt(sspi, SUN4I_INT_CTL_TC | + SUN4I_INT_CTL_RF_F34); + /* Only enable Tx FIFO interrupt if we really need it */ + if (tx_len > SUN4I_FIFO_DEPTH) + sun4i_spi_enable_interrupt(sspi, SUN4I_INT_CTL_TF_E34); + + /* Start the transfer */ + reg = sun4i_spi_read(sspi, SUN4I_CTL_REG); + sun4i_spi_write(sspi, SUN4I_CTL_REG, reg | SUN4I_CTL_XCH); + + tx_time = max(tfr->len * 8 * 2 / (tfr->speed_hz / 1000), 100U); + start = jiffies; + timeout = wait_for_completion_timeout(&sspi->done, + msecs_to_jiffies(tx_time)); + end = jiffies; + if (!timeout) { + dev_warn(&master->dev, + "%s: timeout transferring %u bytes@%iHz for %i(%i)ms", + dev_name(&spi->dev), tfr->len, tfr->speed_hz, + jiffies_to_msecs(end - start), tx_time); + ret = -ETIMEDOUT; + goto out; + } + + +out: + sun4i_spi_write(sspi, SUN4I_INT_CTL_REG, 0); + + return ret; +} + +static irqreturn_t sun4i_spi_handler(int irq, void *dev_id) +{ + struct sun4i_spi *sspi = dev_id; + u32 status = sun4i_spi_read(sspi, SUN4I_INT_STA_REG); + + /* Transfer complete */ + if (status & SUN4I_INT_CTL_TC) { + sun4i_spi_write(sspi, SUN4I_INT_STA_REG, SUN4I_INT_CTL_TC); + sun4i_spi_drain_fifo(sspi, SUN4I_FIFO_DEPTH); + complete(&sspi->done); + return IRQ_HANDLED; + } + + /* Receive FIFO 3/4 full */ + if (status & SUN4I_INT_CTL_RF_F34) { + sun4i_spi_drain_fifo(sspi, SUN4I_FIFO_DEPTH); + /* Only clear the interrupt _after_ draining the FIFO */ + sun4i_spi_write(sspi, SUN4I_INT_STA_REG, SUN4I_INT_CTL_RF_F34); + return IRQ_HANDLED; + } + + /* Transmit FIFO 3/4 empty */ + if (status & SUN4I_INT_CTL_TF_E34) { + sun4i_spi_fill_fifo(sspi, SUN4I_FIFO_DEPTH); + + if (!sspi->len) + /* nothing left to transmit */ + sun4i_spi_disable_interrupt(sspi, SUN4I_INT_CTL_TF_E34); + + /* Only clear the interrupt _after_ re-seeding the FIFO */ + sun4i_spi_write(sspi, SUN4I_INT_STA_REG, SUN4I_INT_CTL_TF_E34); + + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + +static int sun4i_spi_runtime_resume(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + struct sun4i_spi *sspi = spi_master_get_devdata(master); + int ret; + + ret = clk_prepare_enable(sspi->hclk); + if (ret) { + dev_err(dev, "Couldn't enable AHB clock\n"); + goto out; + } + + ret = clk_prepare_enable(sspi->mclk); + if (ret) { + dev_err(dev, "Couldn't enable module clock\n"); + goto err; + } + + sun4i_spi_write(sspi, SUN4I_CTL_REG, + SUN4I_CTL_ENABLE | SUN4I_CTL_MASTER | SUN4I_CTL_TP); + + return 0; + +err: + clk_disable_unprepare(sspi->hclk); +out: + return ret; +} + +static int sun4i_spi_runtime_suspend(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + struct sun4i_spi *sspi = spi_master_get_devdata(master); + + clk_disable_unprepare(sspi->mclk); + clk_disable_unprepare(sspi->hclk); + + return 0; +} + +static int sun4i_spi_probe(struct platform_device *pdev) +{ + struct spi_master *master; + struct sun4i_spi *sspi; + int ret = 0, irq; + + master = spi_alloc_master(&pdev->dev, sizeof(struct sun4i_spi)); + if (!master) { + dev_err(&pdev->dev, "Unable to allocate SPI Master\n"); + return -ENOMEM; + } + + platform_set_drvdata(pdev, master); + sspi = spi_master_get_devdata(master); + + sspi->base_addr = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(sspi->base_addr)) { + ret = PTR_ERR(sspi->base_addr); + goto err_free_master; + } + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + ret = -ENXIO; + goto err_free_master; + } + + ret = devm_request_irq(&pdev->dev, irq, sun4i_spi_handler, + 0, "sun4i-spi", sspi); + if (ret) { + dev_err(&pdev->dev, "Cannot request IRQ\n"); + goto err_free_master; + } + + sspi->master = master; + master->max_speed_hz = 100 * 1000 * 1000; + master->min_speed_hz = 3 * 1000; + master->set_cs = sun4i_spi_set_cs; + master->transfer_one = sun4i_spi_transfer_one; + master->num_chipselect = 4; + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST; + master->bits_per_word_mask = SPI_BPW_MASK(8); + master->dev.of_node = pdev->dev.of_node; + master->auto_runtime_pm = true; + master->max_transfer_size = sun4i_spi_max_transfer_size; + + sspi->hclk = devm_clk_get(&pdev->dev, "ahb"); + if (IS_ERR(sspi->hclk)) { + dev_err(&pdev->dev, "Unable to acquire AHB clock\n"); + ret = PTR_ERR(sspi->hclk); + goto err_free_master; + } + + sspi->mclk = devm_clk_get(&pdev->dev, "mod"); + if (IS_ERR(sspi->mclk)) { + dev_err(&pdev->dev, "Unable to acquire module clock\n"); + ret = PTR_ERR(sspi->mclk); + goto err_free_master; + } + + init_completion(&sspi->done); + + /* + * This wake-up/shutdown pattern is to be able to have the + * device woken up, even if runtime_pm is disabled + */ + ret = sun4i_spi_runtime_resume(&pdev->dev); + if (ret) { + dev_err(&pdev->dev, "Couldn't resume the device\n"); + goto err_free_master; + } + + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + pm_runtime_idle(&pdev->dev); + + ret = devm_spi_register_master(&pdev->dev, master); + if (ret) { + dev_err(&pdev->dev, "cannot register SPI master\n"); + goto err_pm_disable; + } + + return 0; + +err_pm_disable: + pm_runtime_disable(&pdev->dev); + sun4i_spi_runtime_suspend(&pdev->dev); +err_free_master: + spi_master_put(master); + return ret; +} + +static int sun4i_spi_remove(struct platform_device *pdev) +{ + pm_runtime_force_suspend(&pdev->dev); + + return 0; +} + +static const struct of_device_id sun4i_spi_match[] = { + { .compatible = "allwinner,sun4i-a10-spi", }, + {} +}; +MODULE_DEVICE_TABLE(of, sun4i_spi_match); + +static const struct dev_pm_ops sun4i_spi_pm_ops = { + .runtime_resume = sun4i_spi_runtime_resume, + .runtime_suspend = sun4i_spi_runtime_suspend, +}; + +static struct platform_driver sun4i_spi_driver = { + .probe = sun4i_spi_probe, + .remove = sun4i_spi_remove, + .driver = { + .name = "sun4i-spi", + .of_match_table = sun4i_spi_match, + .pm = &sun4i_spi_pm_ops, + }, +}; +module_platform_driver(sun4i_spi_driver); + +MODULE_AUTHOR("Pan Nan <pannan@allwinnertech.com>"); +MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>"); +MODULE_DESCRIPTION("Allwinner A1X/A20 SPI controller driver"); +MODULE_LICENSE("GPL"); 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