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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-bcm-kona.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-bcm-kona.c')
-rw-r--r--drivers/i2c/busses/i2c-bcm-kona.c889
1 files changed, 889 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-bcm-kona.c b/drivers/i2c/busses/i2c-bcm-kona.c
new file mode 100644
index 000000000..f3e369f0f
--- /dev/null
+++ b/drivers/i2c/busses/i2c-bcm-kona.c
@@ -0,0 +1,889 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2013 Broadcom Corporation
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+/* Hardware register offsets and field defintions */
+#define CS_OFFSET 0x00000020
+#define CS_ACK_SHIFT 3
+#define CS_ACK_MASK 0x00000008
+#define CS_ACK_CMD_GEN_START 0x00000000
+#define CS_ACK_CMD_GEN_RESTART 0x00000001
+#define CS_CMD_SHIFT 1
+#define CS_CMD_CMD_NO_ACTION 0x00000000
+#define CS_CMD_CMD_START_RESTART 0x00000001
+#define CS_CMD_CMD_STOP 0x00000002
+#define CS_EN_SHIFT 0
+#define CS_EN_CMD_ENABLE_BSC 0x00000001
+
+#define TIM_OFFSET 0x00000024
+#define TIM_PRESCALE_SHIFT 6
+#define TIM_P_SHIFT 3
+#define TIM_NO_DIV_SHIFT 2
+#define TIM_DIV_SHIFT 0
+
+#define DAT_OFFSET 0x00000028
+
+#define TOUT_OFFSET 0x0000002c
+
+#define TXFCR_OFFSET 0x0000003c
+#define TXFCR_FIFO_FLUSH_MASK 0x00000080
+#define TXFCR_FIFO_EN_MASK 0x00000040
+
+#define IER_OFFSET 0x00000044
+#define IER_READ_COMPLETE_INT_MASK 0x00000010
+#define IER_I2C_INT_EN_MASK 0x00000008
+#define IER_FIFO_INT_EN_MASK 0x00000002
+#define IER_NOACK_EN_MASK 0x00000001
+
+#define ISR_OFFSET 0x00000048
+#define ISR_RESERVED_MASK 0xffffff60
+#define ISR_CMDBUSY_MASK 0x00000080
+#define ISR_READ_COMPLETE_MASK 0x00000010
+#define ISR_SES_DONE_MASK 0x00000008
+#define ISR_ERR_MASK 0x00000004
+#define ISR_TXFIFOEMPTY_MASK 0x00000002
+#define ISR_NOACK_MASK 0x00000001
+
+#define CLKEN_OFFSET 0x0000004C
+#define CLKEN_AUTOSENSE_OFF_MASK 0x00000080
+#define CLKEN_M_SHIFT 4
+#define CLKEN_N_SHIFT 1
+#define CLKEN_CLKEN_MASK 0x00000001
+
+#define FIFO_STATUS_OFFSET 0x00000054
+#define FIFO_STATUS_RXFIFO_EMPTY_MASK 0x00000004
+#define FIFO_STATUS_TXFIFO_EMPTY_MASK 0x00000010
+
+#define HSTIM_OFFSET 0x00000058
+#define HSTIM_HS_MODE_MASK 0x00008000
+#define HSTIM_HS_HOLD_SHIFT 10
+#define HSTIM_HS_HIGH_PHASE_SHIFT 5
+#define HSTIM_HS_SETUP_SHIFT 0
+
+#define PADCTL_OFFSET 0x0000005c
+#define PADCTL_PAD_OUT_EN_MASK 0x00000004
+
+#define RXFCR_OFFSET 0x00000068
+#define RXFCR_NACK_EN_SHIFT 7
+#define RXFCR_READ_COUNT_SHIFT 0
+#define RXFIFORDOUT_OFFSET 0x0000006c
+
+/* Locally used constants */
+#define MAX_RX_FIFO_SIZE 64U /* bytes */
+#define MAX_TX_FIFO_SIZE 64U /* bytes */
+
+#define STD_EXT_CLK_FREQ 13000000UL
+#define HS_EXT_CLK_FREQ 104000000UL
+
+#define MASTERCODE 0x08 /* Mastercodes are 0000_1xxxb */
+
+#define I2C_TIMEOUT 100 /* msecs */
+
+/* Operations that can be commanded to the controller */
+enum bcm_kona_cmd_t {
+ BCM_CMD_NOACTION = 0,
+ BCM_CMD_START,
+ BCM_CMD_RESTART,
+ BCM_CMD_STOP,
+};
+
+enum bus_speed_index {
+ BCM_SPD_100K = 0,
+ BCM_SPD_400K,
+ BCM_SPD_1MHZ,
+};
+
+enum hs_bus_speed_index {
+ BCM_SPD_3P4MHZ = 0,
+};
+
+/* Internal divider settings for standard mode, fast mode and fast mode plus */
+struct bus_speed_cfg {
+ uint8_t time_m; /* Number of cycles for setup time */
+ uint8_t time_n; /* Number of cycles for hold time */
+ uint8_t prescale; /* Prescale divider */
+ uint8_t time_p; /* Timing coefficient */
+ uint8_t no_div; /* Disable clock divider */
+ uint8_t time_div; /* Post-prescale divider */
+};
+
+/* Internal divider settings for high-speed mode */
+struct hs_bus_speed_cfg {
+ uint8_t hs_hold; /* Number of clock cycles SCL stays low until
+ the end of bit period */
+ uint8_t hs_high_phase; /* Number of clock cycles SCL stays high
+ before it falls */
+ uint8_t hs_setup; /* Number of clock cycles SCL stays low
+ before it rises */
+ uint8_t prescale; /* Prescale divider */
+ uint8_t time_p; /* Timing coefficient */
+ uint8_t no_div; /* Disable clock divider */
+ uint8_t time_div; /* Post-prescale divider */
+};
+
+static const struct bus_speed_cfg std_cfg_table[] = {
+ [BCM_SPD_100K] = {0x01, 0x01, 0x03, 0x06, 0x00, 0x02},
+ [BCM_SPD_400K] = {0x05, 0x01, 0x03, 0x05, 0x01, 0x02},
+ [BCM_SPD_1MHZ] = {0x01, 0x01, 0x03, 0x01, 0x01, 0x03},
+};
+
+static const struct hs_bus_speed_cfg hs_cfg_table[] = {
+ [BCM_SPD_3P4MHZ] = {0x01, 0x08, 0x14, 0x00, 0x06, 0x01, 0x00},
+};
+
+struct bcm_kona_i2c_dev {
+ struct device *device;
+
+ void __iomem *base;
+ int irq;
+ struct clk *external_clk;
+
+ struct i2c_adapter adapter;
+
+ struct completion done;
+
+ const struct bus_speed_cfg *std_cfg;
+ const struct hs_bus_speed_cfg *hs_cfg;
+};
+
+static void bcm_kona_i2c_send_cmd_to_ctrl(struct bcm_kona_i2c_dev *dev,
+ enum bcm_kona_cmd_t cmd)
+{
+ dev_dbg(dev->device, "%s, %d\n", __func__, cmd);
+
+ switch (cmd) {
+ case BCM_CMD_NOACTION:
+ writel((CS_CMD_CMD_NO_ACTION << CS_CMD_SHIFT) |
+ (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+ dev->base + CS_OFFSET);
+ break;
+
+ case BCM_CMD_START:
+ writel((CS_ACK_CMD_GEN_START << CS_ACK_SHIFT) |
+ (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
+ (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+ dev->base + CS_OFFSET);
+ break;
+
+ case BCM_CMD_RESTART:
+ writel((CS_ACK_CMD_GEN_RESTART << CS_ACK_SHIFT) |
+ (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
+ (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+ dev->base + CS_OFFSET);
+ break;
+
+ case BCM_CMD_STOP:
+ writel((CS_CMD_CMD_STOP << CS_CMD_SHIFT) |
+ (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+ dev->base + CS_OFFSET);
+ break;
+
+ default:
+ dev_err(dev->device, "Unknown command %d\n", cmd);
+ }
+}
+
+static void bcm_kona_i2c_enable_clock(struct bcm_kona_i2c_dev *dev)
+{
+ writel(readl(dev->base + CLKEN_OFFSET) | CLKEN_CLKEN_MASK,
+ dev->base + CLKEN_OFFSET);
+}
+
+static void bcm_kona_i2c_disable_clock(struct bcm_kona_i2c_dev *dev)
+{
+ writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_CLKEN_MASK,
+ dev->base + CLKEN_OFFSET);
+}
+
+static irqreturn_t bcm_kona_i2c_isr(int irq, void *devid)
+{
+ struct bcm_kona_i2c_dev *dev = devid;
+ uint32_t status = readl(dev->base + ISR_OFFSET);
+
+ if ((status & ~ISR_RESERVED_MASK) == 0)
+ return IRQ_NONE;
+
+ /* Must flush the TX FIFO when NAK detected */
+ if (status & ISR_NOACK_MASK)
+ writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
+ dev->base + TXFCR_OFFSET);
+
+ writel(status & ~ISR_RESERVED_MASK, dev->base + ISR_OFFSET);
+ complete(&dev->done);
+
+ return IRQ_HANDLED;
+}
+
+/* Wait for ISR_CMDBUSY_MASK to go low before writing to CS, DAT, or RCD */
+static int bcm_kona_i2c_wait_if_busy(struct bcm_kona_i2c_dev *dev)
+{
+ unsigned long timeout = jiffies + msecs_to_jiffies(I2C_TIMEOUT);
+
+ while (readl(dev->base + ISR_OFFSET) & ISR_CMDBUSY_MASK)
+ if (time_after(jiffies, timeout)) {
+ dev_err(dev->device, "CMDBUSY timeout\n");
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+
+/* Send command to I2C bus */
+static int bcm_kona_send_i2c_cmd(struct bcm_kona_i2c_dev *dev,
+ enum bcm_kona_cmd_t cmd)
+{
+ int rc;
+ unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT);
+
+ /* Make sure the hardware is ready */
+ rc = bcm_kona_i2c_wait_if_busy(dev);
+ if (rc < 0)
+ return rc;
+
+ /* Unmask the session done interrupt */
+ writel(IER_I2C_INT_EN_MASK, dev->base + IER_OFFSET);
+
+ /* Mark as incomplete before sending the command */
+ reinit_completion(&dev->done);
+
+ /* Send the command */
+ bcm_kona_i2c_send_cmd_to_ctrl(dev, cmd);
+
+ /* Wait for transaction to finish or timeout */
+ time_left = wait_for_completion_timeout(&dev->done, time_left);
+
+ /* Mask all interrupts */
+ writel(0, dev->base + IER_OFFSET);
+
+ if (!time_left) {
+ dev_err(dev->device, "controller timed out\n");
+ rc = -ETIMEDOUT;
+ }
+
+ /* Clear command */
+ bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
+
+ return rc;
+}
+
+/* Read a single RX FIFO worth of data from the i2c bus */
+static int bcm_kona_i2c_read_fifo_single(struct bcm_kona_i2c_dev *dev,
+ uint8_t *buf, unsigned int len,
+ unsigned int last_byte_nak)
+{
+ unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT);
+
+ /* Mark as incomplete before starting the RX FIFO */
+ reinit_completion(&dev->done);
+
+ /* Unmask the read complete interrupt */
+ writel(IER_READ_COMPLETE_INT_MASK, dev->base + IER_OFFSET);
+
+ /* Start the RX FIFO */
+ writel((last_byte_nak << RXFCR_NACK_EN_SHIFT) |
+ (len << RXFCR_READ_COUNT_SHIFT),
+ dev->base + RXFCR_OFFSET);
+
+ /* Wait for FIFO read to complete */
+ time_left = wait_for_completion_timeout(&dev->done, time_left);
+
+ /* Mask all interrupts */
+ writel(0, dev->base + IER_OFFSET);
+
+ if (!time_left) {
+ dev_err(dev->device, "RX FIFO time out\n");
+ return -EREMOTEIO;
+ }
+
+ /* Read data from FIFO */
+ for (; len > 0; len--, buf++)
+ *buf = readl(dev->base + RXFIFORDOUT_OFFSET);
+
+ return 0;
+}
+
+/* Read any amount of data using the RX FIFO from the i2c bus */
+static int bcm_kona_i2c_read_fifo(struct bcm_kona_i2c_dev *dev,
+ struct i2c_msg *msg)
+{
+ unsigned int bytes_to_read = MAX_RX_FIFO_SIZE;
+ unsigned int last_byte_nak = 0;
+ unsigned int bytes_read = 0;
+ int rc;
+
+ uint8_t *tmp_buf = msg->buf;
+
+ while (bytes_read < msg->len) {
+ if (msg->len - bytes_read <= MAX_RX_FIFO_SIZE) {
+ last_byte_nak = 1; /* NAK last byte of transfer */
+ bytes_to_read = msg->len - bytes_read;
+ }
+
+ rc = bcm_kona_i2c_read_fifo_single(dev, tmp_buf, bytes_to_read,
+ last_byte_nak);
+ if (rc < 0)
+ return -EREMOTEIO;
+
+ bytes_read += bytes_to_read;
+ tmp_buf += bytes_to_read;
+ }
+
+ return 0;
+}
+
+/* Write a single byte of data to the i2c bus */
+static int bcm_kona_i2c_write_byte(struct bcm_kona_i2c_dev *dev, uint8_t data,
+ unsigned int nak_expected)
+{
+ int rc;
+ unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT);
+ unsigned int nak_received;
+
+ /* Make sure the hardware is ready */
+ rc = bcm_kona_i2c_wait_if_busy(dev);
+ if (rc < 0)
+ return rc;
+
+ /* Clear pending session done interrupt */
+ writel(ISR_SES_DONE_MASK, dev->base + ISR_OFFSET);
+
+ /* Unmask the session done interrupt */
+ writel(IER_I2C_INT_EN_MASK, dev->base + IER_OFFSET);
+
+ /* Mark as incomplete before sending the data */
+ reinit_completion(&dev->done);
+
+ /* Send one byte of data */
+ writel(data, dev->base + DAT_OFFSET);
+
+ /* Wait for byte to be written */
+ time_left = wait_for_completion_timeout(&dev->done, time_left);
+
+ /* Mask all interrupts */
+ writel(0, dev->base + IER_OFFSET);
+
+ if (!time_left) {
+ dev_dbg(dev->device, "controller timed out\n");
+ return -ETIMEDOUT;
+ }
+
+ nak_received = readl(dev->base + CS_OFFSET) & CS_ACK_MASK ? 1 : 0;
+
+ if (nak_received ^ nak_expected) {
+ dev_dbg(dev->device, "unexpected NAK/ACK\n");
+ return -EREMOTEIO;
+ }
+
+ return 0;
+}
+
+/* Write a single TX FIFO worth of data to the i2c bus */
+static int bcm_kona_i2c_write_fifo_single(struct bcm_kona_i2c_dev *dev,
+ uint8_t *buf, unsigned int len)
+{
+ int k;
+ unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT);
+ unsigned int fifo_status;
+
+ /* Mark as incomplete before sending data to the TX FIFO */
+ reinit_completion(&dev->done);
+
+ /* Unmask the fifo empty and nak interrupt */
+ writel(IER_FIFO_INT_EN_MASK | IER_NOACK_EN_MASK,
+ dev->base + IER_OFFSET);
+
+ /* Disable IRQ to load a FIFO worth of data without interruption */
+ disable_irq(dev->irq);
+
+ /* Write data into FIFO */
+ for (k = 0; k < len; k++)
+ writel(buf[k], (dev->base + DAT_OFFSET));
+
+ /* Enable IRQ now that data has been loaded */
+ enable_irq(dev->irq);
+
+ /* Wait for FIFO to empty */
+ do {
+ time_left = wait_for_completion_timeout(&dev->done, time_left);
+ fifo_status = readl(dev->base + FIFO_STATUS_OFFSET);
+ } while (time_left && !(fifo_status & FIFO_STATUS_TXFIFO_EMPTY_MASK));
+
+ /* Mask all interrupts */
+ writel(0, dev->base + IER_OFFSET);
+
+ /* Check if there was a NAK */
+ if (readl(dev->base + CS_OFFSET) & CS_ACK_MASK) {
+ dev_err(dev->device, "unexpected NAK\n");
+ return -EREMOTEIO;
+ }
+
+ /* Check if a timeout occured */
+ if (!time_left) {
+ dev_err(dev->device, "completion timed out\n");
+ return -EREMOTEIO;
+ }
+
+ return 0;
+}
+
+
+/* Write any amount of data using TX FIFO to the i2c bus */
+static int bcm_kona_i2c_write_fifo(struct bcm_kona_i2c_dev *dev,
+ struct i2c_msg *msg)
+{
+ unsigned int bytes_to_write = MAX_TX_FIFO_SIZE;
+ unsigned int bytes_written = 0;
+ int rc;
+
+ uint8_t *tmp_buf = msg->buf;
+
+ while (bytes_written < msg->len) {
+ if (msg->len - bytes_written <= MAX_TX_FIFO_SIZE)
+ bytes_to_write = msg->len - bytes_written;
+
+ rc = bcm_kona_i2c_write_fifo_single(dev, tmp_buf,
+ bytes_to_write);
+ if (rc < 0)
+ return -EREMOTEIO;
+
+ bytes_written += bytes_to_write;
+ tmp_buf += bytes_to_write;
+ }
+
+ return 0;
+}
+
+/* Send i2c address */
+static int bcm_kona_i2c_do_addr(struct bcm_kona_i2c_dev *dev,
+ struct i2c_msg *msg)
+{
+ unsigned char addr;
+
+ if (msg->flags & I2C_M_TEN) {
+ /* First byte is 11110XX0 where XX is upper 2 bits */
+ addr = 0xF0 | ((msg->addr & 0x300) >> 7);
+ if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+ return -EREMOTEIO;
+
+ /* Second byte is the remaining 8 bits */
+ addr = msg->addr & 0xFF;
+ if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+ return -EREMOTEIO;
+
+ if (msg->flags & I2C_M_RD) {
+ /* For read, send restart command */
+ if (bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART) < 0)
+ return -EREMOTEIO;
+
+ /* Then re-send the first byte with the read bit set */
+ addr = 0xF0 | ((msg->addr & 0x300) >> 7) | 0x01;
+ if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+ return -EREMOTEIO;
+ }
+ } else {
+ addr = i2c_8bit_addr_from_msg(msg);
+
+ if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+ return -EREMOTEIO;
+ }
+
+ return 0;
+}
+
+static void bcm_kona_i2c_enable_autosense(struct bcm_kona_i2c_dev *dev)
+{
+ writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_AUTOSENSE_OFF_MASK,
+ dev->base + CLKEN_OFFSET);
+}
+
+static void bcm_kona_i2c_config_timing(struct bcm_kona_i2c_dev *dev)
+{
+ writel(readl(dev->base + HSTIM_OFFSET) & ~HSTIM_HS_MODE_MASK,
+ dev->base + HSTIM_OFFSET);
+
+ writel((dev->std_cfg->prescale << TIM_PRESCALE_SHIFT) |
+ (dev->std_cfg->time_p << TIM_P_SHIFT) |
+ (dev->std_cfg->no_div << TIM_NO_DIV_SHIFT) |
+ (dev->std_cfg->time_div << TIM_DIV_SHIFT),
+ dev->base + TIM_OFFSET);
+
+ writel((dev->std_cfg->time_m << CLKEN_M_SHIFT) |
+ (dev->std_cfg->time_n << CLKEN_N_SHIFT) |
+ CLKEN_CLKEN_MASK,
+ dev->base + CLKEN_OFFSET);
+}
+
+static void bcm_kona_i2c_config_timing_hs(struct bcm_kona_i2c_dev *dev)
+{
+ writel((dev->hs_cfg->prescale << TIM_PRESCALE_SHIFT) |
+ (dev->hs_cfg->time_p << TIM_P_SHIFT) |
+ (dev->hs_cfg->no_div << TIM_NO_DIV_SHIFT) |
+ (dev->hs_cfg->time_div << TIM_DIV_SHIFT),
+ dev->base + TIM_OFFSET);
+
+ writel((dev->hs_cfg->hs_hold << HSTIM_HS_HOLD_SHIFT) |
+ (dev->hs_cfg->hs_high_phase << HSTIM_HS_HIGH_PHASE_SHIFT) |
+ (dev->hs_cfg->hs_setup << HSTIM_HS_SETUP_SHIFT),
+ dev->base + HSTIM_OFFSET);
+
+ writel(readl(dev->base + HSTIM_OFFSET) | HSTIM_HS_MODE_MASK,
+ dev->base + HSTIM_OFFSET);
+}
+
+static int bcm_kona_i2c_switch_to_hs(struct bcm_kona_i2c_dev *dev)
+{
+ int rc;
+
+ /* Send mastercode at standard speed */
+ rc = bcm_kona_i2c_write_byte(dev, MASTERCODE, 1);
+ if (rc < 0) {
+ pr_err("High speed handshake failed\n");
+ return rc;
+ }
+
+ /* Configure external clock to higher frequency */
+ rc = clk_set_rate(dev->external_clk, HS_EXT_CLK_FREQ);
+ if (rc) {
+ dev_err(dev->device, "%s: clk_set_rate returned %d\n",
+ __func__, rc);
+ return rc;
+ }
+
+ /* Reconfigure internal dividers */
+ bcm_kona_i2c_config_timing_hs(dev);
+
+ /* Send a restart command */
+ rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART);
+ if (rc < 0)
+ dev_err(dev->device, "High speed restart command failed\n");
+
+ return rc;
+}
+
+static int bcm_kona_i2c_switch_to_std(struct bcm_kona_i2c_dev *dev)
+{
+ int rc;
+
+ /* Reconfigure internal dividers */
+ bcm_kona_i2c_config_timing(dev);
+
+ /* Configure external clock to lower frequency */
+ rc = clk_set_rate(dev->external_clk, STD_EXT_CLK_FREQ);
+ if (rc) {
+ dev_err(dev->device, "%s: clk_set_rate returned %d\n",
+ __func__, rc);
+ }
+
+ return rc;
+}
+
+/* Master transfer function */
+static int bcm_kona_i2c_xfer(struct i2c_adapter *adapter,
+ struct i2c_msg msgs[], int num)
+{
+ struct bcm_kona_i2c_dev *dev = i2c_get_adapdata(adapter);
+ struct i2c_msg *pmsg;
+ int rc = 0;
+ int i;
+
+ rc = clk_prepare_enable(dev->external_clk);
+ if (rc) {
+ dev_err(dev->device, "%s: peri clock enable failed. err %d\n",
+ __func__, rc);
+ return rc;
+ }
+
+ /* Enable pad output */
+ writel(0, dev->base + PADCTL_OFFSET);
+
+ /* Enable internal clocks */
+ bcm_kona_i2c_enable_clock(dev);
+
+ /* Send start command */
+ rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_START);
+ if (rc < 0) {
+ dev_err(dev->device, "Start command failed rc = %d\n", rc);
+ goto xfer_disable_pad;
+ }
+
+ /* Switch to high speed if applicable */
+ if (dev->hs_cfg) {
+ rc = bcm_kona_i2c_switch_to_hs(dev);
+ if (rc < 0)
+ goto xfer_send_stop;
+ }
+
+ /* Loop through all messages */
+ for (i = 0; i < num; i++) {
+ pmsg = &msgs[i];
+
+ /* Send restart for subsequent messages */
+ if ((i != 0) && ((pmsg->flags & I2C_M_NOSTART) == 0)) {
+ rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART);
+ if (rc < 0) {
+ dev_err(dev->device,
+ "restart cmd failed rc = %d\n", rc);
+ goto xfer_send_stop;
+ }
+ }
+
+ /* Send slave address */
+ if (!(pmsg->flags & I2C_M_NOSTART)) {
+ rc = bcm_kona_i2c_do_addr(dev, pmsg);
+ if (rc < 0) {
+ dev_err(dev->device,
+ "NAK from addr %2.2x msg#%d rc = %d\n",
+ pmsg->addr, i, rc);
+ goto xfer_send_stop;
+ }
+ }
+
+ /* Perform data transfer */
+ if (pmsg->flags & I2C_M_RD) {
+ rc = bcm_kona_i2c_read_fifo(dev, pmsg);
+ if (rc < 0) {
+ dev_err(dev->device, "read failure\n");
+ goto xfer_send_stop;
+ }
+ } else {
+ rc = bcm_kona_i2c_write_fifo(dev, pmsg);
+ if (rc < 0) {
+ dev_err(dev->device, "write failure");
+ goto xfer_send_stop;
+ }
+ }
+ }
+
+ rc = num;
+
+xfer_send_stop:
+ /* Send a STOP command */
+ bcm_kona_send_i2c_cmd(dev, BCM_CMD_STOP);
+
+ /* Return from high speed if applicable */
+ if (dev->hs_cfg) {
+ int hs_rc = bcm_kona_i2c_switch_to_std(dev);
+
+ if (hs_rc)
+ rc = hs_rc;
+ }
+
+xfer_disable_pad:
+ /* Disable pad output */
+ writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
+
+ /* Stop internal clock */
+ bcm_kona_i2c_disable_clock(dev);
+
+ clk_disable_unprepare(dev->external_clk);
+
+ return rc;
+}
+
+static uint32_t bcm_kona_i2c_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR |
+ I2C_FUNC_NOSTART;
+}
+
+static const struct i2c_algorithm bcm_algo = {
+ .master_xfer = bcm_kona_i2c_xfer,
+ .functionality = bcm_kona_i2c_functionality,
+};
+
+static int bcm_kona_i2c_assign_bus_speed(struct bcm_kona_i2c_dev *dev)
+{
+ unsigned int bus_speed;
+ int ret = of_property_read_u32(dev->device->of_node, "clock-frequency",
+ &bus_speed);
+ if (ret < 0) {
+ dev_err(dev->device, "missing clock-frequency property\n");
+ return -ENODEV;
+ }
+
+ switch (bus_speed) {
+ case I2C_MAX_STANDARD_MODE_FREQ:
+ dev->std_cfg = &std_cfg_table[BCM_SPD_100K];
+ break;
+ case I2C_MAX_FAST_MODE_FREQ:
+ dev->std_cfg = &std_cfg_table[BCM_SPD_400K];
+ break;
+ case I2C_MAX_FAST_MODE_PLUS_FREQ:
+ dev->std_cfg = &std_cfg_table[BCM_SPD_1MHZ];
+ break;
+ case I2C_MAX_HIGH_SPEED_MODE_FREQ:
+ /* Send mastercode at 100k */
+ dev->std_cfg = &std_cfg_table[BCM_SPD_100K];
+ dev->hs_cfg = &hs_cfg_table[BCM_SPD_3P4MHZ];
+ break;
+ default:
+ pr_err("%d hz bus speed not supported\n", bus_speed);
+ pr_err("Valid speeds are 100khz, 400khz, 1mhz, and 3.4mhz\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int bcm_kona_i2c_probe(struct platform_device *pdev)
+{
+ int rc = 0;
+ struct bcm_kona_i2c_dev *dev;
+ struct i2c_adapter *adap;
+
+ /* Allocate memory for private data structure */
+ dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, dev);
+ dev->device = &pdev->dev;
+ init_completion(&dev->done);
+
+ /* Map hardware registers */
+ dev->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(dev->base))
+ return PTR_ERR(dev->base);
+
+ /* Get and enable external clock */
+ dev->external_clk = devm_clk_get(dev->device, NULL);
+ if (IS_ERR(dev->external_clk)) {
+ dev_err(dev->device, "couldn't get clock\n");
+ return -ENODEV;
+ }
+
+ rc = clk_set_rate(dev->external_clk, STD_EXT_CLK_FREQ);
+ if (rc) {
+ dev_err(dev->device, "%s: clk_set_rate returned %d\n",
+ __func__, rc);
+ return rc;
+ }
+
+ rc = clk_prepare_enable(dev->external_clk);
+ if (rc) {
+ dev_err(dev->device, "couldn't enable clock\n");
+ return rc;
+ }
+
+ /* Parse bus speed */
+ rc = bcm_kona_i2c_assign_bus_speed(dev);
+ if (rc)
+ goto probe_disable_clk;
+
+ /* Enable internal clocks */
+ bcm_kona_i2c_enable_clock(dev);
+
+ /* Configure internal dividers */
+ bcm_kona_i2c_config_timing(dev);
+
+ /* Disable timeout */
+ writel(0, dev->base + TOUT_OFFSET);
+
+ /* Enable autosense */
+ bcm_kona_i2c_enable_autosense(dev);
+
+ /* Enable TX FIFO */
+ writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
+ dev->base + TXFCR_OFFSET);
+
+ /* Mask all interrupts */
+ writel(0, dev->base + IER_OFFSET);
+
+ /* Clear all pending interrupts */
+ writel(ISR_CMDBUSY_MASK |
+ ISR_READ_COMPLETE_MASK |
+ ISR_SES_DONE_MASK |
+ ISR_ERR_MASK |
+ ISR_TXFIFOEMPTY_MASK |
+ ISR_NOACK_MASK,
+ dev->base + ISR_OFFSET);
+
+ /* Get the interrupt number */
+ dev->irq = platform_get_irq(pdev, 0);
+ if (dev->irq < 0) {
+ rc = dev->irq;
+ goto probe_disable_clk;
+ }
+
+ /* register the ISR handler */
+ rc = devm_request_irq(&pdev->dev, dev->irq, bcm_kona_i2c_isr,
+ IRQF_SHARED, pdev->name, dev);
+ if (rc) {
+ dev_err(dev->device, "failed to request irq %i\n", dev->irq);
+ goto probe_disable_clk;
+ }
+
+ /* Enable the controller but leave it idle */
+ bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
+
+ /* Disable pad output */
+ writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
+
+ /* Disable internal clock */
+ bcm_kona_i2c_disable_clock(dev);
+
+ /* Disable external clock */
+ clk_disable_unprepare(dev->external_clk);
+
+ /* Add the i2c adapter */
+ adap = &dev->adapter;
+ i2c_set_adapdata(adap, dev);
+ adap->owner = THIS_MODULE;
+ strscpy(adap->name, "Broadcom I2C adapter", sizeof(adap->name));
+ adap->algo = &bcm_algo;
+ adap->dev.parent = &pdev->dev;
+ adap->dev.of_node = pdev->dev.of_node;
+
+ rc = i2c_add_adapter(adap);
+ if (rc)
+ return rc;
+
+ dev_info(dev->device, "device registered successfully\n");
+
+ return 0;
+
+probe_disable_clk:
+ bcm_kona_i2c_disable_clock(dev);
+ clk_disable_unprepare(dev->external_clk);
+
+ return rc;
+}
+
+static int bcm_kona_i2c_remove(struct platform_device *pdev)
+{
+ struct bcm_kona_i2c_dev *dev = platform_get_drvdata(pdev);
+
+ i2c_del_adapter(&dev->adapter);
+
+ return 0;
+}
+
+static const struct of_device_id bcm_kona_i2c_of_match[] = {
+ {.compatible = "brcm,kona-i2c",},
+ {},
+};
+MODULE_DEVICE_TABLE(of, bcm_kona_i2c_of_match);
+
+static struct platform_driver bcm_kona_i2c_driver = {
+ .driver = {
+ .name = "bcm-kona-i2c",
+ .of_match_table = bcm_kona_i2c_of_match,
+ },
+ .probe = bcm_kona_i2c_probe,
+ .remove = bcm_kona_i2c_remove,
+};
+module_platform_driver(bcm_kona_i2c_driver);
+
+MODULE_AUTHOR("Tim Kryger <tkryger@broadcom.com>");
+MODULE_DESCRIPTION("Broadcom Kona I2C Driver");
+MODULE_LICENSE("GPL v2");