aboutsummaryrefslogtreecommitdiff
path: root/drivers/i2c/busses/i2c-xiic.c
diff options
context:
space:
mode:
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/i2c/busses/i2c-xiic.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/i2c/busses/i2c-xiic.c')
-rw-r--r--drivers/i2c/busses/i2c-xiic.c929
1 files changed, 929 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c
new file mode 100644
index 000000000..bee5a2ef1
--- /dev/null
+++ b/drivers/i2c/busses/i2c-xiic.c
@@ -0,0 +1,929 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * i2c-xiic.c
+ * Copyright (c) 2002-2007 Xilinx Inc.
+ * Copyright (c) 2009-2010 Intel Corporation
+ *
+ * This code was implemented by Mocean Laboratories AB when porting linux
+ * to the automotive development board Russellville. The copyright holder
+ * as seen in the header is Intel corporation.
+ * Mocean Laboratories forked off the GNU/Linux platform work into a
+ * separate company called Pelagicore AB, which committed the code to the
+ * kernel.
+ */
+
+/* Supports:
+ * Xilinx IIC
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/completion.h>
+#include <linux/platform_data/i2c-xiic.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/clk.h>
+#include <linux/pm_runtime.h>
+
+#define DRIVER_NAME "xiic-i2c"
+
+enum xilinx_i2c_state {
+ STATE_DONE,
+ STATE_ERROR,
+ STATE_START
+};
+
+enum xiic_endian {
+ LITTLE,
+ BIG
+};
+
+/**
+ * struct xiic_i2c - Internal representation of the XIIC I2C bus
+ * @dev: Pointer to device structure
+ * @base: Memory base of the HW registers
+ * @completion: Completion for callers
+ * @adap: Kernel adapter representation
+ * @tx_msg: Messages from above to be sent
+ * @lock: Mutual exclusion
+ * @tx_pos: Current pos in TX message
+ * @nmsgs: Number of messages in tx_msg
+ * @rx_msg: Current RX message
+ * @rx_pos: Position within current RX message
+ * @endianness: big/little-endian byte order
+ * @clk: Pointer to AXI4-lite input clock
+ * @state: See STATE_
+ * @singlemaster: Indicates bus is single master
+ */
+struct xiic_i2c {
+ struct device *dev;
+ void __iomem *base;
+ struct completion completion;
+ struct i2c_adapter adap;
+ struct i2c_msg *tx_msg;
+ struct mutex lock;
+ unsigned int tx_pos;
+ unsigned int nmsgs;
+ struct i2c_msg *rx_msg;
+ int rx_pos;
+ enum xiic_endian endianness;
+ struct clk *clk;
+ enum xilinx_i2c_state state;
+ bool singlemaster;
+};
+
+#define XIIC_MSB_OFFSET 0
+#define XIIC_REG_OFFSET (0x100 + XIIC_MSB_OFFSET)
+
+/*
+ * Register offsets in bytes from RegisterBase. Three is added to the
+ * base offset to access LSB (IBM style) of the word
+ */
+#define XIIC_CR_REG_OFFSET (0x00 + XIIC_REG_OFFSET) /* Control Register */
+#define XIIC_SR_REG_OFFSET (0x04 + XIIC_REG_OFFSET) /* Status Register */
+#define XIIC_DTR_REG_OFFSET (0x08 + XIIC_REG_OFFSET) /* Data Tx Register */
+#define XIIC_DRR_REG_OFFSET (0x0C + XIIC_REG_OFFSET) /* Data Rx Register */
+#define XIIC_ADR_REG_OFFSET (0x10 + XIIC_REG_OFFSET) /* Address Register */
+#define XIIC_TFO_REG_OFFSET (0x14 + XIIC_REG_OFFSET) /* Tx FIFO Occupancy */
+#define XIIC_RFO_REG_OFFSET (0x18 + XIIC_REG_OFFSET) /* Rx FIFO Occupancy */
+#define XIIC_TBA_REG_OFFSET (0x1C + XIIC_REG_OFFSET) /* 10 Bit Address reg */
+#define XIIC_RFD_REG_OFFSET (0x20 + XIIC_REG_OFFSET) /* Rx FIFO Depth reg */
+#define XIIC_GPO_REG_OFFSET (0x24 + XIIC_REG_OFFSET) /* Output Register */
+
+/* Control Register masks */
+#define XIIC_CR_ENABLE_DEVICE_MASK 0x01 /* Device enable = 1 */
+#define XIIC_CR_TX_FIFO_RESET_MASK 0x02 /* Transmit FIFO reset=1 */
+#define XIIC_CR_MSMS_MASK 0x04 /* Master starts Txing=1 */
+#define XIIC_CR_DIR_IS_TX_MASK 0x08 /* Dir of tx. Txing=1 */
+#define XIIC_CR_NO_ACK_MASK 0x10 /* Tx Ack. NO ack = 1 */
+#define XIIC_CR_REPEATED_START_MASK 0x20 /* Repeated start = 1 */
+#define XIIC_CR_GENERAL_CALL_MASK 0x40 /* Gen Call enabled = 1 */
+
+/* Status Register masks */
+#define XIIC_SR_GEN_CALL_MASK 0x01 /* 1=a mstr issued a GC */
+#define XIIC_SR_ADDR_AS_SLAVE_MASK 0x02 /* 1=when addr as slave */
+#define XIIC_SR_BUS_BUSY_MASK 0x04 /* 1 = bus is busy */
+#define XIIC_SR_MSTR_RDING_SLAVE_MASK 0x08 /* 1=Dir: mstr <-- slave */
+#define XIIC_SR_TX_FIFO_FULL_MASK 0x10 /* 1 = Tx FIFO full */
+#define XIIC_SR_RX_FIFO_FULL_MASK 0x20 /* 1 = Rx FIFO full */
+#define XIIC_SR_RX_FIFO_EMPTY_MASK 0x40 /* 1 = Rx FIFO empty */
+#define XIIC_SR_TX_FIFO_EMPTY_MASK 0x80 /* 1 = Tx FIFO empty */
+
+/* Interrupt Status Register masks Interrupt occurs when... */
+#define XIIC_INTR_ARB_LOST_MASK 0x01 /* 1 = arbitration lost */
+#define XIIC_INTR_TX_ERROR_MASK 0x02 /* 1=Tx error/msg complete */
+#define XIIC_INTR_TX_EMPTY_MASK 0x04 /* 1 = Tx FIFO/reg empty */
+#define XIIC_INTR_RX_FULL_MASK 0x08 /* 1=Rx FIFO/reg=OCY level */
+#define XIIC_INTR_BNB_MASK 0x10 /* 1 = Bus not busy */
+#define XIIC_INTR_AAS_MASK 0x20 /* 1 = when addr as slave */
+#define XIIC_INTR_NAAS_MASK 0x40 /* 1 = not addr as slave */
+#define XIIC_INTR_TX_HALF_MASK 0x80 /* 1 = TX FIFO half empty */
+
+/* The following constants specify the depth of the FIFOs */
+#define IIC_RX_FIFO_DEPTH 16 /* Rx fifo capacity */
+#define IIC_TX_FIFO_DEPTH 16 /* Tx fifo capacity */
+
+/* The following constants specify groups of interrupts that are typically
+ * enabled or disables at the same time
+ */
+#define XIIC_TX_INTERRUPTS \
+(XIIC_INTR_TX_ERROR_MASK | XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)
+
+#define XIIC_TX_RX_INTERRUPTS (XIIC_INTR_RX_FULL_MASK | XIIC_TX_INTERRUPTS)
+
+/*
+ * Tx Fifo upper bit masks.
+ */
+#define XIIC_TX_DYN_START_MASK 0x0100 /* 1 = Set dynamic start */
+#define XIIC_TX_DYN_STOP_MASK 0x0200 /* 1 = Set dynamic stop */
+
+/*
+ * The following constants define the register offsets for the Interrupt
+ * registers. There are some holes in the memory map for reserved addresses
+ * to allow other registers to be added and still match the memory map of the
+ * interrupt controller registers
+ */
+#define XIIC_DGIER_OFFSET 0x1C /* Device Global Interrupt Enable Register */
+#define XIIC_IISR_OFFSET 0x20 /* Interrupt Status Register */
+#define XIIC_IIER_OFFSET 0x28 /* Interrupt Enable Register */
+#define XIIC_RESETR_OFFSET 0x40 /* Reset Register */
+
+#define XIIC_RESET_MASK 0xAUL
+
+#define XIIC_PM_TIMEOUT 1000 /* ms */
+/* timeout waiting for the controller to respond */
+#define XIIC_I2C_TIMEOUT (msecs_to_jiffies(1000))
+/* timeout waiting for the controller finish transfers */
+#define XIIC_XFER_TIMEOUT (msecs_to_jiffies(10000))
+
+/*
+ * The following constant is used for the device global interrupt enable
+ * register, to enable all interrupts for the device, this is the only bit
+ * in the register
+ */
+#define XIIC_GINTR_ENABLE_MASK 0x80000000UL
+
+#define xiic_tx_space(i2c) ((i2c)->tx_msg->len - (i2c)->tx_pos)
+#define xiic_rx_space(i2c) ((i2c)->rx_msg->len - (i2c)->rx_pos)
+
+static int xiic_start_xfer(struct xiic_i2c *i2c, struct i2c_msg *msgs, int num);
+static void __xiic_start_xfer(struct xiic_i2c *i2c);
+
+/*
+ * For the register read and write functions, a little-endian and big-endian
+ * version are necessary. Endianness is detected during the probe function.
+ * Only the least significant byte [doublet] of the register are ever
+ * accessed. This requires an offset of 3 [2] from the base address for
+ * big-endian systems.
+ */
+
+static inline void xiic_setreg8(struct xiic_i2c *i2c, int reg, u8 value)
+{
+ if (i2c->endianness == LITTLE)
+ iowrite8(value, i2c->base + reg);
+ else
+ iowrite8(value, i2c->base + reg + 3);
+}
+
+static inline u8 xiic_getreg8(struct xiic_i2c *i2c, int reg)
+{
+ u8 ret;
+
+ if (i2c->endianness == LITTLE)
+ ret = ioread8(i2c->base + reg);
+ else
+ ret = ioread8(i2c->base + reg + 3);
+ return ret;
+}
+
+static inline void xiic_setreg16(struct xiic_i2c *i2c, int reg, u16 value)
+{
+ if (i2c->endianness == LITTLE)
+ iowrite16(value, i2c->base + reg);
+ else
+ iowrite16be(value, i2c->base + reg + 2);
+}
+
+static inline void xiic_setreg32(struct xiic_i2c *i2c, int reg, int value)
+{
+ if (i2c->endianness == LITTLE)
+ iowrite32(value, i2c->base + reg);
+ else
+ iowrite32be(value, i2c->base + reg);
+}
+
+static inline int xiic_getreg32(struct xiic_i2c *i2c, int reg)
+{
+ u32 ret;
+
+ if (i2c->endianness == LITTLE)
+ ret = ioread32(i2c->base + reg);
+ else
+ ret = ioread32be(i2c->base + reg);
+ return ret;
+}
+
+static inline void xiic_irq_dis(struct xiic_i2c *i2c, u32 mask)
+{
+ u32 ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET);
+
+ xiic_setreg32(i2c, XIIC_IIER_OFFSET, ier & ~mask);
+}
+
+static inline void xiic_irq_en(struct xiic_i2c *i2c, u32 mask)
+{
+ u32 ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET);
+
+ xiic_setreg32(i2c, XIIC_IIER_OFFSET, ier | mask);
+}
+
+static inline void xiic_irq_clr(struct xiic_i2c *i2c, u32 mask)
+{
+ u32 isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET);
+
+ xiic_setreg32(i2c, XIIC_IISR_OFFSET, isr & mask);
+}
+
+static inline void xiic_irq_clr_en(struct xiic_i2c *i2c, u32 mask)
+{
+ xiic_irq_clr(i2c, mask);
+ xiic_irq_en(i2c, mask);
+}
+
+static int xiic_clear_rx_fifo(struct xiic_i2c *i2c)
+{
+ u8 sr;
+ unsigned long timeout;
+
+ timeout = jiffies + XIIC_I2C_TIMEOUT;
+ for (sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET);
+ !(sr & XIIC_SR_RX_FIFO_EMPTY_MASK);
+ sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET)) {
+ xiic_getreg8(i2c, XIIC_DRR_REG_OFFSET);
+ if (time_after(jiffies, timeout)) {
+ dev_err(i2c->dev, "Failed to clear rx fifo\n");
+ return -ETIMEDOUT;
+ }
+ }
+
+ return 0;
+}
+
+static int xiic_reinit(struct xiic_i2c *i2c)
+{
+ int ret;
+
+ xiic_setreg32(i2c, XIIC_RESETR_OFFSET, XIIC_RESET_MASK);
+
+ /* Set receive Fifo depth to maximum (zero based). */
+ xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, IIC_RX_FIFO_DEPTH - 1);
+
+ /* Reset Tx Fifo. */
+ xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, XIIC_CR_TX_FIFO_RESET_MASK);
+
+ /* Enable IIC Device, remove Tx Fifo reset & disable general call. */
+ xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, XIIC_CR_ENABLE_DEVICE_MASK);
+
+ /* make sure RX fifo is empty */
+ ret = xiic_clear_rx_fifo(i2c);
+ if (ret)
+ return ret;
+
+ /* Enable interrupts */
+ xiic_setreg32(i2c, XIIC_DGIER_OFFSET, XIIC_GINTR_ENABLE_MASK);
+
+ xiic_irq_clr_en(i2c, XIIC_INTR_ARB_LOST_MASK);
+
+ return 0;
+}
+
+static void xiic_deinit(struct xiic_i2c *i2c)
+{
+ u8 cr;
+
+ xiic_setreg32(i2c, XIIC_RESETR_OFFSET, XIIC_RESET_MASK);
+
+ /* Disable IIC Device. */
+ cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET);
+ xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr & ~XIIC_CR_ENABLE_DEVICE_MASK);
+}
+
+static void xiic_read_rx(struct xiic_i2c *i2c)
+{
+ u8 bytes_in_fifo;
+ int i;
+
+ bytes_in_fifo = xiic_getreg8(i2c, XIIC_RFO_REG_OFFSET) + 1;
+
+ dev_dbg(i2c->adap.dev.parent,
+ "%s entry, bytes in fifo: %d, msg: %d, SR: 0x%x, CR: 0x%x\n",
+ __func__, bytes_in_fifo, xiic_rx_space(i2c),
+ xiic_getreg8(i2c, XIIC_SR_REG_OFFSET),
+ xiic_getreg8(i2c, XIIC_CR_REG_OFFSET));
+
+ if (bytes_in_fifo > xiic_rx_space(i2c))
+ bytes_in_fifo = xiic_rx_space(i2c);
+
+ for (i = 0; i < bytes_in_fifo; i++)
+ i2c->rx_msg->buf[i2c->rx_pos++] =
+ xiic_getreg8(i2c, XIIC_DRR_REG_OFFSET);
+
+ xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET,
+ (xiic_rx_space(i2c) > IIC_RX_FIFO_DEPTH) ?
+ IIC_RX_FIFO_DEPTH - 1 : xiic_rx_space(i2c) - 1);
+}
+
+static int xiic_tx_fifo_space(struct xiic_i2c *i2c)
+{
+ /* return the actual space left in the FIFO */
+ return IIC_TX_FIFO_DEPTH - xiic_getreg8(i2c, XIIC_TFO_REG_OFFSET) - 1;
+}
+
+static void xiic_fill_tx_fifo(struct xiic_i2c *i2c)
+{
+ u8 fifo_space = xiic_tx_fifo_space(i2c);
+ int len = xiic_tx_space(i2c);
+
+ len = (len > fifo_space) ? fifo_space : len;
+
+ dev_dbg(i2c->adap.dev.parent, "%s entry, len: %d, fifo space: %d\n",
+ __func__, len, fifo_space);
+
+ while (len--) {
+ u16 data = i2c->tx_msg->buf[i2c->tx_pos++];
+
+ if (!xiic_tx_space(i2c) && i2c->nmsgs == 1) {
+ /* last message in transfer -> STOP */
+ data |= XIIC_TX_DYN_STOP_MASK;
+ dev_dbg(i2c->adap.dev.parent, "%s TX STOP\n", __func__);
+ }
+ xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data);
+ }
+}
+
+static void xiic_wakeup(struct xiic_i2c *i2c, enum xilinx_i2c_state code)
+{
+ i2c->tx_msg = NULL;
+ i2c->rx_msg = NULL;
+ i2c->nmsgs = 0;
+ i2c->state = code;
+ complete(&i2c->completion);
+}
+
+static irqreturn_t xiic_process(int irq, void *dev_id)
+{
+ struct xiic_i2c *i2c = dev_id;
+ u32 pend, isr, ier;
+ u32 clr = 0;
+ int xfer_more = 0;
+ int wakeup_req = 0;
+ enum xilinx_i2c_state wakeup_code = STATE_DONE;
+ int ret;
+
+ /* Get the interrupt Status from the IPIF. There is no clearing of
+ * interrupts in the IPIF. Interrupts must be cleared at the source.
+ * To find which interrupts are pending; AND interrupts pending with
+ * interrupts masked.
+ */
+ mutex_lock(&i2c->lock);
+ isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET);
+ ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET);
+ pend = isr & ier;
+
+ dev_dbg(i2c->adap.dev.parent, "%s: IER: 0x%x, ISR: 0x%x, pend: 0x%x\n",
+ __func__, ier, isr, pend);
+ dev_dbg(i2c->adap.dev.parent, "%s: SR: 0x%x, msg: %p, nmsgs: %d\n",
+ __func__, xiic_getreg8(i2c, XIIC_SR_REG_OFFSET),
+ i2c->tx_msg, i2c->nmsgs);
+
+
+ /* Service requesting interrupt */
+ if ((pend & XIIC_INTR_ARB_LOST_MASK) ||
+ ((pend & XIIC_INTR_TX_ERROR_MASK) &&
+ !(pend & XIIC_INTR_RX_FULL_MASK))) {
+ /* bus arbritration lost, or...
+ * Transmit error _OR_ RX completed
+ * if this happens when RX_FULL is not set
+ * this is probably a TX error
+ */
+
+ dev_dbg(i2c->adap.dev.parent, "%s error\n", __func__);
+
+ /* dynamic mode seem to suffer from problems if we just flushes
+ * fifos and the next message is a TX with len 0 (only addr)
+ * reset the IP instead of just flush fifos
+ */
+ ret = xiic_reinit(i2c);
+ if (!ret)
+ dev_dbg(i2c->adap.dev.parent, "reinit failed\n");
+
+ if (i2c->rx_msg) {
+ wakeup_req = 1;
+ wakeup_code = STATE_ERROR;
+ }
+ if (i2c->tx_msg) {
+ wakeup_req = 1;
+ wakeup_code = STATE_ERROR;
+ }
+ }
+ if (pend & XIIC_INTR_RX_FULL_MASK) {
+ /* Receive register/FIFO is full */
+
+ clr |= XIIC_INTR_RX_FULL_MASK;
+ if (!i2c->rx_msg) {
+ dev_dbg(i2c->adap.dev.parent,
+ "%s unexpected RX IRQ\n", __func__);
+ xiic_clear_rx_fifo(i2c);
+ goto out;
+ }
+
+ xiic_read_rx(i2c);
+ if (xiic_rx_space(i2c) == 0) {
+ /* this is the last part of the message */
+ i2c->rx_msg = NULL;
+
+ /* also clear TX error if there (RX complete) */
+ clr |= (isr & XIIC_INTR_TX_ERROR_MASK);
+
+ dev_dbg(i2c->adap.dev.parent,
+ "%s end of message, nmsgs: %d\n",
+ __func__, i2c->nmsgs);
+
+ /* send next message if this wasn't the last,
+ * otherwise the transfer will be finialise when
+ * receiving the bus not busy interrupt
+ */
+ if (i2c->nmsgs > 1) {
+ i2c->nmsgs--;
+ i2c->tx_msg++;
+ dev_dbg(i2c->adap.dev.parent,
+ "%s will start next...\n", __func__);
+ xfer_more = 1;
+ }
+ }
+ }
+ if (pend & (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)) {
+ /* Transmit register/FIFO is empty or ½ empty */
+
+ clr |= (pend &
+ (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK));
+
+ if (!i2c->tx_msg) {
+ dev_dbg(i2c->adap.dev.parent,
+ "%s unexpected TX IRQ\n", __func__);
+ goto out;
+ }
+
+ xiic_fill_tx_fifo(i2c);
+
+ /* current message sent and there is space in the fifo */
+ if (!xiic_tx_space(i2c) && xiic_tx_fifo_space(i2c) >= 2) {
+ dev_dbg(i2c->adap.dev.parent,
+ "%s end of message sent, nmsgs: %d\n",
+ __func__, i2c->nmsgs);
+ if (i2c->nmsgs > 1) {
+ i2c->nmsgs--;
+ i2c->tx_msg++;
+ xfer_more = 1;
+ } else {
+ xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK);
+
+ dev_dbg(i2c->adap.dev.parent,
+ "%s Got TX IRQ but no more to do...\n",
+ __func__);
+ }
+ } else if (!xiic_tx_space(i2c) && (i2c->nmsgs == 1))
+ /* current frame is sent and is last,
+ * make sure to disable tx half
+ */
+ xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK);
+ }
+
+ if (pend & XIIC_INTR_BNB_MASK) {
+ /* IIC bus has transitioned to not busy */
+ clr |= XIIC_INTR_BNB_MASK;
+
+ /* The bus is not busy, disable BusNotBusy interrupt */
+ xiic_irq_dis(i2c, XIIC_INTR_BNB_MASK);
+
+ if (!i2c->tx_msg)
+ goto out;
+
+ wakeup_req = 1;
+
+ if (i2c->nmsgs == 1 && !i2c->rx_msg &&
+ xiic_tx_space(i2c) == 0)
+ wakeup_code = STATE_DONE;
+ else
+ wakeup_code = STATE_ERROR;
+ }
+
+out:
+ dev_dbg(i2c->adap.dev.parent, "%s clr: 0x%x\n", __func__, clr);
+
+ xiic_setreg32(i2c, XIIC_IISR_OFFSET, clr);
+ if (xfer_more)
+ __xiic_start_xfer(i2c);
+ if (wakeup_req)
+ xiic_wakeup(i2c, wakeup_code);
+
+ WARN_ON(xfer_more && wakeup_req);
+
+ mutex_unlock(&i2c->lock);
+ return IRQ_HANDLED;
+}
+
+static int xiic_bus_busy(struct xiic_i2c *i2c)
+{
+ u8 sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET);
+
+ return (sr & XIIC_SR_BUS_BUSY_MASK) ? -EBUSY : 0;
+}
+
+static int xiic_busy(struct xiic_i2c *i2c)
+{
+ int tries = 3;
+ int err;
+
+ if (i2c->tx_msg || i2c->rx_msg)
+ return -EBUSY;
+
+ /* In single master mode bus can only be busy, when in use by this
+ * driver. If the register indicates bus being busy for some reason we
+ * should ignore it, since bus will never be released and i2c will be
+ * stuck forever.
+ */
+ if (i2c->singlemaster) {
+ return 0;
+ }
+
+ /* for instance if previous transfer was terminated due to TX error
+ * it might be that the bus is on it's way to become available
+ * give it at most 3 ms to wake
+ */
+ err = xiic_bus_busy(i2c);
+ while (err && tries--) {
+ msleep(1);
+ err = xiic_bus_busy(i2c);
+ }
+
+ return err;
+}
+
+static void xiic_start_recv(struct xiic_i2c *i2c)
+{
+ u16 rx_watermark;
+ struct i2c_msg *msg = i2c->rx_msg = i2c->tx_msg;
+
+ /* Clear and enable Rx full interrupt. */
+ xiic_irq_clr_en(i2c, XIIC_INTR_RX_FULL_MASK | XIIC_INTR_TX_ERROR_MASK);
+
+ /* we want to get all but last byte, because the TX_ERROR IRQ is used
+ * to inidicate error ACK on the address, and negative ack on the last
+ * received byte, so to not mix them receive all but last.
+ * In the case where there is only one byte to receive
+ * we can check if ERROR and RX full is set at the same time
+ */
+ rx_watermark = msg->len;
+ if (rx_watermark > IIC_RX_FIFO_DEPTH)
+ rx_watermark = IIC_RX_FIFO_DEPTH;
+ xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, (u8)(rx_watermark - 1));
+
+ if (!(msg->flags & I2C_M_NOSTART))
+ /* write the address */
+ xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET,
+ i2c_8bit_addr_from_msg(msg) | XIIC_TX_DYN_START_MASK);
+
+ xiic_irq_clr_en(i2c, XIIC_INTR_BNB_MASK);
+
+ xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET,
+ msg->len | ((i2c->nmsgs == 1) ? XIIC_TX_DYN_STOP_MASK : 0));
+
+ if (i2c->nmsgs == 1)
+ /* very last, enable bus not busy as well */
+ xiic_irq_clr_en(i2c, XIIC_INTR_BNB_MASK);
+
+ /* the message is tx:ed */
+ i2c->tx_pos = msg->len;
+}
+
+static void xiic_start_send(struct xiic_i2c *i2c)
+{
+ struct i2c_msg *msg = i2c->tx_msg;
+
+ dev_dbg(i2c->adap.dev.parent, "%s entry, msg: %p, len: %d",
+ __func__, msg, msg->len);
+ dev_dbg(i2c->adap.dev.parent, "%s entry, ISR: 0x%x, CR: 0x%x\n",
+ __func__, xiic_getreg32(i2c, XIIC_IISR_OFFSET),
+ xiic_getreg8(i2c, XIIC_CR_REG_OFFSET));
+
+ if (!(msg->flags & I2C_M_NOSTART)) {
+ /* write the address */
+ u16 data = i2c_8bit_addr_from_msg(msg) |
+ XIIC_TX_DYN_START_MASK;
+ if ((i2c->nmsgs == 1) && msg->len == 0)
+ /* no data and last message -> add STOP */
+ data |= XIIC_TX_DYN_STOP_MASK;
+
+ xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data);
+ }
+
+ /* Clear any pending Tx empty, Tx Error and then enable them. */
+ xiic_irq_clr_en(i2c, XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_ERROR_MASK |
+ XIIC_INTR_BNB_MASK |
+ ((i2c->nmsgs > 1 || xiic_tx_space(i2c)) ?
+ XIIC_INTR_TX_HALF_MASK : 0));
+
+ xiic_fill_tx_fifo(i2c);
+}
+
+static void __xiic_start_xfer(struct xiic_i2c *i2c)
+{
+ int fifo_space = xiic_tx_fifo_space(i2c);
+
+ dev_dbg(i2c->adap.dev.parent, "%s entry, msg: %p, fifos space: %d\n",
+ __func__, i2c->tx_msg, fifo_space);
+
+ if (!i2c->tx_msg)
+ return;
+
+ i2c->rx_pos = 0;
+ i2c->tx_pos = 0;
+ i2c->state = STATE_START;
+ if (i2c->tx_msg->flags & I2C_M_RD) {
+ /* we dont date putting several reads in the FIFO */
+ xiic_start_recv(i2c);
+ } else {
+ xiic_start_send(i2c);
+ }
+}
+
+static int xiic_start_xfer(struct xiic_i2c *i2c, struct i2c_msg *msgs, int num)
+{
+ int ret;
+
+ mutex_lock(&i2c->lock);
+
+ ret = xiic_busy(i2c);
+ if (ret)
+ goto out;
+
+ i2c->tx_msg = msgs;
+ i2c->rx_msg = NULL;
+ i2c->nmsgs = num;
+ init_completion(&i2c->completion);
+
+ ret = xiic_reinit(i2c);
+ if (!ret)
+ __xiic_start_xfer(i2c);
+
+out:
+ mutex_unlock(&i2c->lock);
+
+ return ret;
+}
+
+static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ struct xiic_i2c *i2c = i2c_get_adapdata(adap);
+ int err;
+
+ dev_dbg(adap->dev.parent, "%s entry SR: 0x%x\n", __func__,
+ xiic_getreg8(i2c, XIIC_SR_REG_OFFSET));
+
+ err = pm_runtime_resume_and_get(i2c->dev);
+ if (err < 0)
+ return err;
+
+ err = xiic_start_xfer(i2c, msgs, num);
+ if (err < 0) {
+ dev_err(adap->dev.parent, "Error xiic_start_xfer\n");
+ return err;
+ }
+
+ err = wait_for_completion_timeout(&i2c->completion, XIIC_XFER_TIMEOUT);
+ mutex_lock(&i2c->lock);
+ if (err == 0) { /* Timeout */
+ i2c->tx_msg = NULL;
+ i2c->rx_msg = NULL;
+ i2c->nmsgs = 0;
+ err = -ETIMEDOUT;
+ } else if (err < 0) { /* Completion error */
+ i2c->tx_msg = NULL;
+ i2c->rx_msg = NULL;
+ i2c->nmsgs = 0;
+ } else {
+ err = (i2c->state == STATE_DONE) ? num : -EIO;
+ }
+ mutex_unlock(&i2c->lock);
+ pm_runtime_mark_last_busy(i2c->dev);
+ pm_runtime_put_autosuspend(i2c->dev);
+ return err;
+}
+
+static u32 xiic_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm xiic_algorithm = {
+ .master_xfer = xiic_xfer,
+ .functionality = xiic_func,
+};
+
+static const struct i2c_adapter_quirks xiic_quirks = {
+ .max_read_len = 255,
+};
+
+static const struct i2c_adapter xiic_adapter = {
+ .owner = THIS_MODULE,
+ .class = I2C_CLASS_DEPRECATED,
+ .algo = &xiic_algorithm,
+ .quirks = &xiic_quirks,
+};
+
+static int xiic_i2c_probe(struct platform_device *pdev)
+{
+ struct xiic_i2c *i2c;
+ struct xiic_i2c_platform_data *pdata;
+ struct resource *res;
+ int ret, irq;
+ u8 i;
+ u32 sr;
+
+ i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
+ if (!i2c)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ i2c->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(i2c->base))
+ return PTR_ERR(i2c->base);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+
+ pdata = dev_get_platdata(&pdev->dev);
+
+ /* hook up driver to tree */
+ platform_set_drvdata(pdev, i2c);
+ i2c->adap = xiic_adapter;
+ i2c_set_adapdata(&i2c->adap, i2c);
+ i2c->adap.dev.parent = &pdev->dev;
+ i2c->adap.dev.of_node = pdev->dev.of_node;
+ snprintf(i2c->adap.name, sizeof(i2c->adap.name),
+ DRIVER_NAME " %s", pdev->name);
+
+ mutex_init(&i2c->lock);
+
+ i2c->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(i2c->clk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(i2c->clk),
+ "input clock not found.\n");
+
+ ret = clk_prepare_enable(i2c->clk);
+ if (ret) {
+ dev_err(&pdev->dev, "Unable to enable clock.\n");
+ return ret;
+ }
+ i2c->dev = &pdev->dev;
+ pm_runtime_set_autosuspend_delay(i2c->dev, XIIC_PM_TIMEOUT);
+ pm_runtime_use_autosuspend(i2c->dev);
+ pm_runtime_set_active(i2c->dev);
+ pm_runtime_enable(i2c->dev);
+ ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+ xiic_process, IRQF_ONESHOT,
+ pdev->name, i2c);
+
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Cannot claim IRQ\n");
+ goto err_clk_dis;
+ }
+
+ i2c->singlemaster =
+ of_property_read_bool(pdev->dev.of_node, "single-master");
+
+ /*
+ * Detect endianness
+ * Try to reset the TX FIFO. Then check the EMPTY flag. If it is not
+ * set, assume that the endianness was wrong and swap.
+ */
+ i2c->endianness = LITTLE;
+ xiic_setreg32(i2c, XIIC_CR_REG_OFFSET, XIIC_CR_TX_FIFO_RESET_MASK);
+ /* Reset is cleared in xiic_reinit */
+ sr = xiic_getreg32(i2c, XIIC_SR_REG_OFFSET);
+ if (!(sr & XIIC_SR_TX_FIFO_EMPTY_MASK))
+ i2c->endianness = BIG;
+
+ ret = xiic_reinit(i2c);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Cannot xiic_reinit\n");
+ goto err_clk_dis;
+ }
+
+ /* add i2c adapter to i2c tree */
+ ret = i2c_add_adapter(&i2c->adap);
+ if (ret) {
+ xiic_deinit(i2c);
+ goto err_clk_dis;
+ }
+
+ if (pdata) {
+ /* add in known devices to the bus */
+ for (i = 0; i < pdata->num_devices; i++)
+ i2c_new_client_device(&i2c->adap, pdata->devices + i);
+ }
+
+ return 0;
+
+err_clk_dis:
+ pm_runtime_set_suspended(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+ clk_disable_unprepare(i2c->clk);
+ return ret;
+}
+
+static int xiic_i2c_remove(struct platform_device *pdev)
+{
+ struct xiic_i2c *i2c = platform_get_drvdata(pdev);
+ int ret;
+
+ /* remove adapter & data */
+ i2c_del_adapter(&i2c->adap);
+
+ ret = pm_runtime_get_sync(i2c->dev);
+
+ if (ret < 0)
+ dev_warn(&pdev->dev, "Failed to activate device for removal (%pe)\n",
+ ERR_PTR(ret));
+ else
+ xiic_deinit(i2c);
+
+ pm_runtime_put_sync(i2c->dev);
+ clk_disable_unprepare(i2c->clk);
+ pm_runtime_disable(&pdev->dev);
+ pm_runtime_set_suspended(&pdev->dev);
+ pm_runtime_dont_use_autosuspend(&pdev->dev);
+
+ return 0;
+}
+
+#if defined(CONFIG_OF)
+static const struct of_device_id xiic_of_match[] = {
+ { .compatible = "xlnx,xps-iic-2.00.a", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, xiic_of_match);
+#endif
+
+static int __maybe_unused xiic_i2c_runtime_suspend(struct device *dev)
+{
+ struct xiic_i2c *i2c = dev_get_drvdata(dev);
+
+ clk_disable(i2c->clk);
+
+ return 0;
+}
+
+static int __maybe_unused xiic_i2c_runtime_resume(struct device *dev)
+{
+ struct xiic_i2c *i2c = dev_get_drvdata(dev);
+ int ret;
+
+ ret = clk_enable(i2c->clk);
+ if (ret) {
+ dev_err(dev, "Cannot enable clock.\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct dev_pm_ops xiic_dev_pm_ops = {
+ SET_RUNTIME_PM_OPS(xiic_i2c_runtime_suspend,
+ xiic_i2c_runtime_resume, NULL)
+};
+
+static struct platform_driver xiic_i2c_driver = {
+ .probe = xiic_i2c_probe,
+ .remove = xiic_i2c_remove,
+ .driver = {
+ .name = DRIVER_NAME,
+ .of_match_table = of_match_ptr(xiic_of_match),
+ .pm = &xiic_dev_pm_ops,
+ },
+};
+
+module_platform_driver(xiic_i2c_driver);
+
+MODULE_ALIAS("platform:" DRIVER_NAME);
+MODULE_AUTHOR("info@mocean-labs.com");
+MODULE_DESCRIPTION("Xilinx I2C bus driver");
+MODULE_LICENSE("GPL v2");