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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/i2c/busses/i2c-owl.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-owl.c')
-rw-r--r--drivers/i2c/busses/i2c-owl.c531
1 files changed, 531 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-owl.c b/drivers/i2c/busses/i2c-owl.c
new file mode 100644
index 000000000..98882fe4e
--- /dev/null
+++ b/drivers/i2c/busses/i2c-owl.c
@@ -0,0 +1,531 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Actions Semiconductor Owl SoC's I2C driver
+ *
+ * Copyright (c) 2014 Actions Semi Inc.
+ * Author: David Liu <liuwei@actions-semi.com>
+ *
+ * Copyright (c) 2018 Linaro Ltd.
+ * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+
+/* I2C registers */
+#define OWL_I2C_REG_CTL 0x0000
+#define OWL_I2C_REG_CLKDIV 0x0004
+#define OWL_I2C_REG_STAT 0x0008
+#define OWL_I2C_REG_ADDR 0x000C
+#define OWL_I2C_REG_TXDAT 0x0010
+#define OWL_I2C_REG_RXDAT 0x0014
+#define OWL_I2C_REG_CMD 0x0018
+#define OWL_I2C_REG_FIFOCTL 0x001C
+#define OWL_I2C_REG_FIFOSTAT 0x0020
+#define OWL_I2C_REG_DATCNT 0x0024
+#define OWL_I2C_REG_RCNT 0x0028
+
+/* I2Cx_CTL Bit Mask */
+#define OWL_I2C_CTL_RB BIT(1)
+#define OWL_I2C_CTL_GBCC(x) (((x) & 0x3) << 2)
+#define OWL_I2C_CTL_GBCC_NONE OWL_I2C_CTL_GBCC(0)
+#define OWL_I2C_CTL_GBCC_START OWL_I2C_CTL_GBCC(1)
+#define OWL_I2C_CTL_GBCC_STOP OWL_I2C_CTL_GBCC(2)
+#define OWL_I2C_CTL_GBCC_RSTART OWL_I2C_CTL_GBCC(3)
+#define OWL_I2C_CTL_IRQE BIT(5)
+#define OWL_I2C_CTL_EN BIT(7)
+#define OWL_I2C_CTL_AE BIT(8)
+#define OWL_I2C_CTL_SHSM BIT(10)
+
+#define OWL_I2C_DIV_FACTOR(x) ((x) & 0xff)
+
+/* I2Cx_STAT Bit Mask */
+#define OWL_I2C_STAT_RACK BIT(0)
+#define OWL_I2C_STAT_BEB BIT(1)
+#define OWL_I2C_STAT_IRQP BIT(2)
+#define OWL_I2C_STAT_LAB BIT(3)
+#define OWL_I2C_STAT_STPD BIT(4)
+#define OWL_I2C_STAT_STAD BIT(5)
+#define OWL_I2C_STAT_BBB BIT(6)
+#define OWL_I2C_STAT_TCB BIT(7)
+#define OWL_I2C_STAT_LBST BIT(8)
+#define OWL_I2C_STAT_SAMB BIT(9)
+#define OWL_I2C_STAT_SRGC BIT(10)
+
+/* I2Cx_CMD Bit Mask */
+#define OWL_I2C_CMD_SBE BIT(0)
+#define OWL_I2C_CMD_RBE BIT(4)
+#define OWL_I2C_CMD_DE BIT(8)
+#define OWL_I2C_CMD_NS BIT(9)
+#define OWL_I2C_CMD_SE BIT(10)
+#define OWL_I2C_CMD_MSS BIT(11)
+#define OWL_I2C_CMD_WRS BIT(12)
+#define OWL_I2C_CMD_SECL BIT(15)
+
+#define OWL_I2C_CMD_AS(x) (((x) & 0x7) << 1)
+#define OWL_I2C_CMD_SAS(x) (((x) & 0x7) << 5)
+
+/* I2Cx_FIFOCTL Bit Mask */
+#define OWL_I2C_FIFOCTL_NIB BIT(0)
+#define OWL_I2C_FIFOCTL_RFR BIT(1)
+#define OWL_I2C_FIFOCTL_TFR BIT(2)
+
+/* I2Cc_FIFOSTAT Bit Mask */
+#define OWL_I2C_FIFOSTAT_CECB BIT(0)
+#define OWL_I2C_FIFOSTAT_RNB BIT(1)
+#define OWL_I2C_FIFOSTAT_RFE BIT(2)
+#define OWL_I2C_FIFOSTAT_TFF BIT(5)
+#define OWL_I2C_FIFOSTAT_TFD GENMASK(23, 16)
+#define OWL_I2C_FIFOSTAT_RFD GENMASK(15, 8)
+
+/* I2C bus timeout */
+#define OWL_I2C_TIMEOUT_MS (4 * 1000)
+#define OWL_I2C_TIMEOUT msecs_to_jiffies(OWL_I2C_TIMEOUT_MS)
+
+#define OWL_I2C_MAX_RETRIES 50
+
+struct owl_i2c_dev {
+ struct i2c_adapter adap;
+ struct i2c_msg *msg;
+ struct completion msg_complete;
+ struct clk *clk;
+ spinlock_t lock;
+ void __iomem *base;
+ unsigned long clk_rate;
+ u32 bus_freq;
+ u32 msg_ptr;
+ int err;
+};
+
+static void owl_i2c_update_reg(void __iomem *reg, unsigned int val, bool state)
+{
+ unsigned int regval;
+
+ regval = readl(reg);
+
+ if (state)
+ regval |= val;
+ else
+ regval &= ~val;
+
+ writel(regval, reg);
+}
+
+static void owl_i2c_reset(struct owl_i2c_dev *i2c_dev)
+{
+ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL,
+ OWL_I2C_CTL_EN, false);
+ mdelay(1);
+ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL,
+ OWL_I2C_CTL_EN, true);
+
+ /* Clear status registers */
+ writel(0, i2c_dev->base + OWL_I2C_REG_STAT);
+}
+
+static int owl_i2c_reset_fifo(struct owl_i2c_dev *i2c_dev)
+{
+ unsigned int val, timeout = 0;
+
+ /* Reset FIFO */
+ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_FIFOCTL,
+ OWL_I2C_FIFOCTL_RFR | OWL_I2C_FIFOCTL_TFR,
+ true);
+
+ /* Wait 50ms for FIFO reset complete */
+ do {
+ val = readl(i2c_dev->base + OWL_I2C_REG_FIFOCTL);
+ if (!(val & (OWL_I2C_FIFOCTL_RFR | OWL_I2C_FIFOCTL_TFR)))
+ break;
+ usleep_range(500, 1000);
+ } while (timeout++ < OWL_I2C_MAX_RETRIES);
+
+ if (timeout > OWL_I2C_MAX_RETRIES) {
+ dev_err(&i2c_dev->adap.dev, "FIFO reset timeout\n");
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+
+static void owl_i2c_set_freq(struct owl_i2c_dev *i2c_dev)
+{
+ unsigned int val;
+
+ val = DIV_ROUND_UP(i2c_dev->clk_rate, i2c_dev->bus_freq * 16);
+
+ /* Set clock divider factor */
+ writel(OWL_I2C_DIV_FACTOR(val), i2c_dev->base + OWL_I2C_REG_CLKDIV);
+}
+
+static void owl_i2c_xfer_data(struct owl_i2c_dev *i2c_dev)
+{
+ struct i2c_msg *msg = i2c_dev->msg;
+ unsigned int stat, fifostat;
+
+ i2c_dev->err = 0;
+
+ /* Handle NACK from slave */
+ fifostat = readl(i2c_dev->base + OWL_I2C_REG_FIFOSTAT);
+ if (fifostat & OWL_I2C_FIFOSTAT_RNB) {
+ i2c_dev->err = -ENXIO;
+ /* Clear NACK error bit by writing "1" */
+ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_FIFOSTAT,
+ OWL_I2C_FIFOSTAT_RNB, true);
+ return;
+ }
+
+ /* Handle bus error */
+ stat = readl(i2c_dev->base + OWL_I2C_REG_STAT);
+ if (stat & OWL_I2C_STAT_BEB) {
+ i2c_dev->err = -EIO;
+ /* Clear BUS error bit by writing "1" */
+ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_STAT,
+ OWL_I2C_STAT_BEB, true);
+ return;
+ }
+
+ /* Handle FIFO read */
+ if (msg->flags & I2C_M_RD) {
+ while ((readl(i2c_dev->base + OWL_I2C_REG_FIFOSTAT) &
+ OWL_I2C_FIFOSTAT_RFE) && i2c_dev->msg_ptr < msg->len) {
+ msg->buf[i2c_dev->msg_ptr++] = readl(i2c_dev->base +
+ OWL_I2C_REG_RXDAT);
+ }
+ } else {
+ /* Handle the remaining bytes which were not sent */
+ while (!(readl(i2c_dev->base + OWL_I2C_REG_FIFOSTAT) &
+ OWL_I2C_FIFOSTAT_TFF) && i2c_dev->msg_ptr < msg->len) {
+ writel(msg->buf[i2c_dev->msg_ptr++],
+ i2c_dev->base + OWL_I2C_REG_TXDAT);
+ }
+ }
+}
+
+static irqreturn_t owl_i2c_interrupt(int irq, void *_dev)
+{
+ struct owl_i2c_dev *i2c_dev = _dev;
+
+ spin_lock(&i2c_dev->lock);
+
+ owl_i2c_xfer_data(i2c_dev);
+
+ /* Clear pending interrupts */
+ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_STAT,
+ OWL_I2C_STAT_IRQP, true);
+
+ complete_all(&i2c_dev->msg_complete);
+ spin_unlock(&i2c_dev->lock);
+
+ return IRQ_HANDLED;
+}
+
+static u32 owl_i2c_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static int owl_i2c_check_bus_busy(struct i2c_adapter *adap)
+{
+ struct owl_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
+ unsigned long timeout;
+
+ /* Check for Bus busy */
+ timeout = jiffies + OWL_I2C_TIMEOUT;
+ while (readl(i2c_dev->base + OWL_I2C_REG_STAT) & OWL_I2C_STAT_BBB) {
+ if (time_after(jiffies, timeout)) {
+ dev_err(&adap->dev, "Bus busy timeout\n");
+ return -ETIMEDOUT;
+ }
+ }
+
+ return 0;
+}
+
+static int owl_i2c_xfer_common(struct i2c_adapter *adap, struct i2c_msg *msgs,
+ int num, bool atomic)
+{
+ struct owl_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
+ struct i2c_msg *msg;
+ unsigned long time_left, flags;
+ unsigned int i2c_cmd, val;
+ unsigned int addr;
+ int ret, idx;
+
+ spin_lock_irqsave(&i2c_dev->lock, flags);
+
+ /* Reset I2C controller */
+ owl_i2c_reset(i2c_dev);
+
+ /* Set bus frequency */
+ owl_i2c_set_freq(i2c_dev);
+
+ /*
+ * Spinlock should be released before calling reset FIFO and
+ * bus busy check since those functions may sleep
+ */
+ spin_unlock_irqrestore(&i2c_dev->lock, flags);
+
+ /* Reset FIFO */
+ ret = owl_i2c_reset_fifo(i2c_dev);
+ if (ret)
+ goto unlocked_err_exit;
+
+ /* Check for bus busy */
+ ret = owl_i2c_check_bus_busy(adap);
+ if (ret)
+ goto unlocked_err_exit;
+
+ spin_lock_irqsave(&i2c_dev->lock, flags);
+
+ /* Check for Arbitration lost */
+ val = readl(i2c_dev->base + OWL_I2C_REG_STAT);
+ if (val & OWL_I2C_STAT_LAB) {
+ val &= ~OWL_I2C_STAT_LAB;
+ writel(val, i2c_dev->base + OWL_I2C_REG_STAT);
+ ret = -EAGAIN;
+ goto err_exit;
+ }
+
+ if (!atomic)
+ reinit_completion(&i2c_dev->msg_complete);
+
+ /* Enable/disable I2C controller interrupt */
+ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL,
+ OWL_I2C_CTL_IRQE, !atomic);
+
+ /*
+ * Select: FIFO enable, Master mode, Stop enable, Data count enable,
+ * Send start bit
+ */
+ i2c_cmd = OWL_I2C_CMD_SECL | OWL_I2C_CMD_MSS | OWL_I2C_CMD_SE |
+ OWL_I2C_CMD_NS | OWL_I2C_CMD_DE | OWL_I2C_CMD_SBE;
+
+ /* Handle repeated start condition */
+ if (num > 1) {
+ /* Set internal address length and enable repeated start */
+ i2c_cmd |= OWL_I2C_CMD_AS(msgs[0].len + 1) |
+ OWL_I2C_CMD_SAS(1) | OWL_I2C_CMD_RBE;
+
+ /* Write slave address */
+ addr = i2c_8bit_addr_from_msg(&msgs[0]);
+ writel(addr, i2c_dev->base + OWL_I2C_REG_TXDAT);
+
+ /* Write internal register address */
+ for (idx = 0; idx < msgs[0].len; idx++)
+ writel(msgs[0].buf[idx],
+ i2c_dev->base + OWL_I2C_REG_TXDAT);
+
+ msg = &msgs[1];
+ } else {
+ /* Set address length */
+ i2c_cmd |= OWL_I2C_CMD_AS(1);
+ msg = &msgs[0];
+ }
+
+ i2c_dev->msg = msg;
+ i2c_dev->msg_ptr = 0;
+
+ /* Set data count for the message */
+ writel(msg->len, i2c_dev->base + OWL_I2C_REG_DATCNT);
+
+ addr = i2c_8bit_addr_from_msg(msg);
+ writel(addr, i2c_dev->base + OWL_I2C_REG_TXDAT);
+
+ if (!(msg->flags & I2C_M_RD)) {
+ /* Write data to FIFO */
+ for (idx = 0; idx < msg->len; idx++) {
+ /* Check for FIFO full */
+ if (readl(i2c_dev->base + OWL_I2C_REG_FIFOSTAT) &
+ OWL_I2C_FIFOSTAT_TFF)
+ break;
+
+ writel(msg->buf[idx],
+ i2c_dev->base + OWL_I2C_REG_TXDAT);
+ }
+
+ i2c_dev->msg_ptr = idx;
+ }
+
+ /* Ignore the NACK if needed */
+ if (msg->flags & I2C_M_IGNORE_NAK)
+ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_FIFOCTL,
+ OWL_I2C_FIFOCTL_NIB, true);
+ else
+ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_FIFOCTL,
+ OWL_I2C_FIFOCTL_NIB, false);
+
+ /* Start the transfer */
+ writel(i2c_cmd, i2c_dev->base + OWL_I2C_REG_CMD);
+
+ spin_unlock_irqrestore(&i2c_dev->lock, flags);
+
+ if (atomic) {
+ /* Wait for Command Execute Completed or NACK Error bits */
+ ret = readl_poll_timeout_atomic(i2c_dev->base + OWL_I2C_REG_FIFOSTAT,
+ val, val & (OWL_I2C_FIFOSTAT_CECB |
+ OWL_I2C_FIFOSTAT_RNB),
+ 10, OWL_I2C_TIMEOUT_MS * 1000);
+ } else {
+ time_left = wait_for_completion_timeout(&i2c_dev->msg_complete,
+ adap->timeout);
+ if (!time_left)
+ ret = -ETIMEDOUT;
+ }
+
+ spin_lock_irqsave(&i2c_dev->lock, flags);
+
+ if (ret) {
+ dev_err(&adap->dev, "Transaction timed out\n");
+ /* Send stop condition and release the bus */
+ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL,
+ OWL_I2C_CTL_GBCC_STOP | OWL_I2C_CTL_RB,
+ true);
+ goto err_exit;
+ }
+
+ if (atomic)
+ owl_i2c_xfer_data(i2c_dev);
+
+ ret = i2c_dev->err < 0 ? i2c_dev->err : num;
+
+err_exit:
+ spin_unlock_irqrestore(&i2c_dev->lock, flags);
+
+unlocked_err_exit:
+ /* Disable I2C controller */
+ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL,
+ OWL_I2C_CTL_EN, false);
+
+ return ret;
+}
+
+static int owl_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+ int num)
+{
+ return owl_i2c_xfer_common(adap, msgs, num, false);
+}
+
+static int owl_i2c_xfer_atomic(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ return owl_i2c_xfer_common(adap, msgs, num, true);
+}
+
+static const struct i2c_algorithm owl_i2c_algorithm = {
+ .master_xfer = owl_i2c_xfer,
+ .master_xfer_atomic = owl_i2c_xfer_atomic,
+ .functionality = owl_i2c_func,
+};
+
+static const struct i2c_adapter_quirks owl_i2c_quirks = {
+ .flags = I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST,
+ .max_read_len = 240,
+ .max_write_len = 240,
+ .max_comb_1st_msg_len = 6,
+ .max_comb_2nd_msg_len = 240,
+};
+
+static int owl_i2c_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct owl_i2c_dev *i2c_dev;
+ int ret, irq;
+
+ i2c_dev = devm_kzalloc(dev, sizeof(*i2c_dev), GFP_KERNEL);
+ if (!i2c_dev)
+ return -ENOMEM;
+
+ i2c_dev->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(i2c_dev->base))
+ return PTR_ERR(i2c_dev->base);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+
+ if (of_property_read_u32(dev->of_node, "clock-frequency",
+ &i2c_dev->bus_freq))
+ i2c_dev->bus_freq = I2C_MAX_STANDARD_MODE_FREQ;
+
+ /* We support only frequencies of 100k and 400k for now */
+ if (i2c_dev->bus_freq != I2C_MAX_STANDARD_MODE_FREQ &&
+ i2c_dev->bus_freq != I2C_MAX_FAST_MODE_FREQ) {
+ dev_err(dev, "invalid clock-frequency %d\n", i2c_dev->bus_freq);
+ return -EINVAL;
+ }
+
+ i2c_dev->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(i2c_dev->clk)) {
+ dev_err(dev, "failed to get clock\n");
+ return PTR_ERR(i2c_dev->clk);
+ }
+
+ ret = clk_prepare_enable(i2c_dev->clk);
+ if (ret)
+ return ret;
+
+ i2c_dev->clk_rate = clk_get_rate(i2c_dev->clk);
+ if (!i2c_dev->clk_rate) {
+ dev_err(dev, "input clock rate should not be zero\n");
+ ret = -EINVAL;
+ goto disable_clk;
+ }
+
+ init_completion(&i2c_dev->msg_complete);
+ spin_lock_init(&i2c_dev->lock);
+ i2c_dev->adap.owner = THIS_MODULE;
+ i2c_dev->adap.algo = &owl_i2c_algorithm;
+ i2c_dev->adap.timeout = OWL_I2C_TIMEOUT;
+ i2c_dev->adap.quirks = &owl_i2c_quirks;
+ i2c_dev->adap.dev.parent = dev;
+ i2c_dev->adap.dev.of_node = dev->of_node;
+ snprintf(i2c_dev->adap.name, sizeof(i2c_dev->adap.name),
+ "%s", "OWL I2C adapter");
+ i2c_set_adapdata(&i2c_dev->adap, i2c_dev);
+
+ platform_set_drvdata(pdev, i2c_dev);
+
+ ret = devm_request_irq(dev, irq, owl_i2c_interrupt, 0, pdev->name,
+ i2c_dev);
+ if (ret) {
+ dev_err(dev, "failed to request irq %d\n", irq);
+ goto disable_clk;
+ }
+
+ return i2c_add_adapter(&i2c_dev->adap);
+
+disable_clk:
+ clk_disable_unprepare(i2c_dev->clk);
+
+ return ret;
+}
+
+static const struct of_device_id owl_i2c_of_match[] = {
+ { .compatible = "actions,s500-i2c" },
+ { .compatible = "actions,s700-i2c" },
+ { .compatible = "actions,s900-i2c" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, owl_i2c_of_match);
+
+static struct platform_driver owl_i2c_driver = {
+ .probe = owl_i2c_probe,
+ .driver = {
+ .name = "owl-i2c",
+ .of_match_table = of_match_ptr(owl_i2c_of_match),
+ .probe_type = PROBE_PREFER_ASYNCHRONOUS,
+ },
+};
+module_platform_driver(owl_i2c_driver);
+
+MODULE_AUTHOR("David Liu <liuwei@actions-semi.com>");
+MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
+MODULE_DESCRIPTION("Actions Semiconductor Owl SoC's I2C driver");
+MODULE_LICENSE("GPL");