diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-07-12 10:04:56 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-07-12 10:04:56 -0700 |
commit | 235b84fc862ae2637dc0dabada18d97f1bfc18e1 (patch) | |
tree | c89a1a8ffa7765fc7fa7cfe1ba4c033eb886a87d /drivers/i2c | |
parent | fb4e3beeffa47619985f190663c6ef424f063a22 (diff) | |
parent | 8f1a357d41a22009150cf404b5aa5876efdb59b1 (diff) |
Merge branch 'i2c/for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
"This pull request contains:
- i2c core reorganization. One source file became too monolithic. It
is now split up, yet we still have the same named object as the
final output. This should ease maintenance.
- new drivers: ZTE ZX2967 family, ASPEED 24XX/25XX
- designware driver gained slave mode support
- xgene-slimpro driver gained ACPI support
- bigger overhaul for pca-platform driver
- the algo-bit module now supports messages with enforced STOP
- slightly bigger than usual set of driver updates and improvements
and with much appreciated quality assurance from Andy Shevchenko"
* 'i2c/for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (51 commits)
i2c: Provide a stub for i2c_detect_slave_mode()
i2c: designware: Let slave adapter support be optional
i2c: designware: Make HW init functions static
i2c: designware: fix spelling mistakes
i2c: pca-platform: propagate error from i2c_pca_add_numbered_bus
i2c: pca-platform: correctly set algo_data.reset_chip
i2c: acpi: Do not create i2c-clients for LNXVIDEO ACPI devices
i2c: designware: enable SLAVE in platform module
i2c: designware: add SLAVE mode functions
i2c: zx2967: drop COMPILE_TEST dependency
i2c: zx2967: always use the same device when printing errors
i2c: pca-platform: use dev_warn/dev_info instead of printk
i2c: pca-platform: use device managed allocations
i2c: pca-platform: add devicetree awareness
i2c: pca-platform: switch to struct gpio_desc
dt-bindings: add bindings for i2c-pca-platform
i2c: cadance: fix ctrl/addr reg write order
i2c: zx2967: add i2c controller driver for ZTE's zx2967 family
dt: bindings: add documentation for zx2967 family i2c controller
i2c: algo-bit: add support for I2C_M_STOP
...
Diffstat (limited to 'drivers/i2c')
29 files changed, 4551 insertions, 2239 deletions
diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index 45095b3d16a9..7bb65a4369e1 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -4,6 +4,11 @@ obj-$(CONFIG_I2C_BOARDINFO) += i2c-boardinfo.o obj-$(CONFIG_I2C) += i2c-core.o +i2c-core-objs := i2c-core-base.o i2c-core-smbus.o +i2c-core-$(CONFIG_ACPI) += i2c-core-acpi.o +i2c-core-$(CONFIG_I2C_SLAVE) += i2c-core-slave.o +i2c-core-$(CONFIG_OF) += i2c-core-of.o + obj-$(CONFIG_I2C_SMBUS) += i2c-smbus.o obj-$(CONFIG_I2C_CHARDEV) += i2c-dev.o obj-$(CONFIG_I2C_MUX) += i2c-mux.o @@ -12,4 +17,4 @@ obj-$(CONFIG_I2C_STUB) += i2c-stub.o obj-$(CONFIG_I2C_SLAVE_EEPROM) += i2c-slave-eeprom.o ccflags-$(CONFIG_I2C_DEBUG_CORE) := -DDEBUG -CFLAGS_i2c-core.o := -Wno-deprecated-declarations +CFLAGS_i2c-core-base.o := -Wno-deprecated-declarations diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c index a8e89df665b9..1147bddb8b2c 100644 --- a/drivers/i2c/algos/i2c-algo-bit.c +++ b/drivers/i2c/algos/i2c-algo-bit.c @@ -553,9 +553,16 @@ static int bit_xfer(struct i2c_adapter *i2c_adap, nak_ok = pmsg->flags & I2C_M_IGNORE_NAK; if (!(pmsg->flags & I2C_M_NOSTART)) { if (i) { - bit_dbg(3, &i2c_adap->dev, "emitting " - "repeated start condition\n"); - i2c_repstart(adap); + if (msgs[i - 1].flags & I2C_M_STOP) { + bit_dbg(3, &i2c_adap->dev, + "emitting enforced stop/start condition\n"); + i2c_stop(adap); + i2c_start(adap); + } else { + bit_dbg(3, &i2c_adap->dev, + "emitting repeated start condition\n"); + i2c_repstart(adap); + } } ret = bit_doAddress(i2c_adap, pmsg); if ((ret != 0) && !nak_ok) { diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 144cbadc7c72..1006b230b236 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -129,6 +129,8 @@ config I2C_I801 Broxton (SOC) Lewisburg (PCH) Gemini Lake (SOC) + Cannon Lake-H (PCH) + Cannon Lake-LP (PCH) This driver can also be built as a module. If so, the module will be called i2c-i801. @@ -326,6 +328,16 @@ config I2C_POWERMAC comment "I2C system bus drivers (mostly embedded / system-on-chip)" +config I2C_ASPEED + tristate "Aspeed I2C Controller" + depends on ARCH_ASPEED || COMPILE_TEST + help + If you say yes to this option, support will be included for the + Aspeed I2C controller. + + This driver can also be built as a module. If so, the module + will be called i2c-aspeed. + config I2C_AT91 tristate "Atmel AT91 I2C Two-Wire interface (TWI)" depends on ARCH_AT91 @@ -474,11 +486,22 @@ config I2C_DESIGNWARE_PLATFORM depends on (ACPI && COMMON_CLK) || !ACPI help If you say yes to this option, support will be included for the - Synopsys DesignWare I2C adapter. Only master mode is supported. + Synopsys DesignWare I2C adapter. This driver can also be built as a module. If so, the module will be called i2c-designware-platform. +config I2C_DESIGNWARE_SLAVE + bool "Synopsys DesignWare Slave" + select I2C_SLAVE + depends on I2C_DESIGNWARE_PLATFORM + help + If you say yes to this option, support will be included for the + Synopsys DesignWare I2C slave adapter. + + This is not a standalone module, this module compiles together with + i2c-designware-core. + config I2C_DESIGNWARE_PCI tristate "Synopsys DesignWare PCI" depends on PCI @@ -1258,4 +1281,13 @@ config I2C_OPAL This driver can also be built as a module. If so, the module will be called as i2c-opal. +config I2C_ZX2967 + tristate "ZTE ZX2967 I2C support" + depends on ARCH_ZX + default y + help + Selecting this option will add ZX2967 I2C driver. + This driver can also be built as a module. If so, the module will be + called i2c-zx2967. + endmenu diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 30b60855fbcd..1b2fc815a4d8 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_I2C_HYDRA) += i2c-hydra.o obj-$(CONFIG_I2C_POWERMAC) += i2c-powermac.o # Embedded system I2C/SMBus host controller drivers +obj-$(CONFIG_I2C_ASPEED) += i2c-aspeed.o obj-$(CONFIG_I2C_AT91) += i2c-at91.o obj-$(CONFIG_I2C_AU1550) += i2c-au1550.o obj-$(CONFIG_I2C_AXXIA) += i2c-axxia.o @@ -40,6 +41,10 @@ obj-$(CONFIG_I2C_CBUS_GPIO) += i2c-cbus-gpio.o obj-$(CONFIG_I2C_CPM) += i2c-cpm.o obj-$(CONFIG_I2C_DAVINCI) += i2c-davinci.o obj-$(CONFIG_I2C_DESIGNWARE_CORE) += i2c-designware-core.o +i2c-designware-core-objs := i2c-designware-common.o i2c-designware-master.o +ifeq ($(CONFIG_I2C_DESIGNWARE_SLAVE),y) +i2c-designware-core-objs += i2c-designware-slave.o +endif obj-$(CONFIG_I2C_DESIGNWARE_PLATFORM) += i2c-designware-platform.o i2c-designware-platform-objs := i2c-designware-platdrv.o i2c-designware-platform-$(CONFIG_I2C_DESIGNWARE_BAYTRAIL) += i2c-designware-baytrail.o @@ -102,6 +107,7 @@ obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o obj-$(CONFIG_I2C_XLR) += i2c-xlr.o obj-$(CONFIG_I2C_XLP9XX) += i2c-xlp9xx.o obj-$(CONFIG_I2C_RCAR) += i2c-rcar.o +obj-$(CONFIG_I2C_ZX2967) += i2c-zx2967.o # External I2C/SMBus adapter drivers obj-$(CONFIG_I2C_DIOLAN_U2C) += i2c-diolan-u2c.o diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c new file mode 100644 index 000000000000..f19348328a71 --- /dev/null +++ b/drivers/i2c/busses/i2c-aspeed.c @@ -0,0 +1,891 @@ +/* + * Aspeed 24XX/25XX I2C Controller. + * + * Copyright (C) 2012-2017 ASPEED Technology Inc. + * Copyright 2017 IBM Corporation + * Copyright 2017 Google, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/clk.h> +#include <linux/completion.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/irqchip/chained_irq.h> +#include <linux/irqdomain.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +/* I2C Register */ +#define ASPEED_I2C_FUN_CTRL_REG 0x00 +#define ASPEED_I2C_AC_TIMING_REG1 0x04 +#define ASPEED_I2C_AC_TIMING_REG2 0x08 +#define ASPEED_I2C_INTR_CTRL_REG 0x0c +#define ASPEED_I2C_INTR_STS_REG 0x10 +#define ASPEED_I2C_CMD_REG 0x14 +#define ASPEED_I2C_DEV_ADDR_REG 0x18 +#define ASPEED_I2C_BYTE_BUF_REG 0x20 + +/* Global Register Definition */ +/* 0x00 : I2C Interrupt Status Register */ +/* 0x08 : I2C Interrupt Target Assignment */ + +/* Device Register Definition */ +/* 0x00 : I2CD Function Control Register */ +#define ASPEED_I2CD_MULTI_MASTER_DIS BIT(15) +#define ASPEED_I2CD_SDA_DRIVE_1T_EN BIT(8) +#define ASPEED_I2CD_M_SDA_DRIVE_1T_EN BIT(7) +#define ASPEED_I2CD_M_HIGH_SPEED_EN BIT(6) +#define ASPEED_I2CD_SLAVE_EN BIT(1) +#define ASPEED_I2CD_MASTER_EN BIT(0) + +/* 0x04 : I2CD Clock and AC Timing Control Register #1 */ +#define ASPEED_I2CD_TIME_SCL_HIGH_SHIFT 16 +#define ASPEED_I2CD_TIME_SCL_HIGH_MASK GENMASK(19, 16) +#define ASPEED_I2CD_TIME_SCL_LOW_SHIFT 12 +#define ASPEED_I2CD_TIME_SCL_LOW_MASK GENMASK(15, 12) +#define ASPEED_I2CD_TIME_BASE_DIVISOR_MASK GENMASK(3, 0) +#define ASPEED_I2CD_TIME_SCL_REG_MAX GENMASK(3, 0) +/* 0x08 : I2CD Clock and AC Timing Control Register #2 */ +#define ASPEED_NO_TIMEOUT_CTRL 0 + +/* 0x0c : I2CD Interrupt Control Register & + * 0x10 : I2CD Interrupt Status Register + * + * These share bit definitions, so use the same values for the enable & + * status bits. + */ +#define ASPEED_I2CD_INTR_SDA_DL_TIMEOUT BIT(14) +#define ASPEED_I2CD_INTR_BUS_RECOVER_DONE BIT(13) +#define ASPEED_I2CD_INTR_SLAVE_MATCH BIT(7) +#define ASPEED_I2CD_INTR_SCL_TIMEOUT BIT(6) +#define ASPEED_I2CD_INTR_ABNORMAL BIT(5) +#define ASPEED_I2CD_INTR_NORMAL_STOP BIT(4) +#define ASPEED_I2CD_INTR_ARBIT_LOSS BIT(3) +#define ASPEED_I2CD_INTR_RX_DONE BIT(2) +#define ASPEED_I2CD_INTR_TX_NAK BIT(1) +#define ASPEED_I2CD_INTR_TX_ACK BIT(0) +#define ASPEED_I2CD_INTR_ALL \ + (ASPEED_I2CD_INTR_SDA_DL_TIMEOUT | \ + ASPEED_I2CD_INTR_BUS_RECOVER_DONE | \ + ASPEED_I2CD_INTR_SCL_TIMEOUT | \ + ASPEED_I2CD_INTR_ABNORMAL | \ + ASPEED_I2CD_INTR_NORMAL_STOP | \ + ASPEED_I2CD_INTR_ARBIT_LOSS | \ + ASPEED_I2CD_INTR_RX_DONE | \ + ASPEED_I2CD_INTR_TX_NAK | \ + ASPEED_I2CD_INTR_TX_ACK) + +/* 0x14 : I2CD Command/Status Register */ +#define ASPEED_I2CD_SCL_LINE_STS BIT(18) +#define ASPEED_I2CD_SDA_LINE_STS BIT(17) +#define ASPEED_I2CD_BUS_BUSY_STS BIT(16) +#define ASPEED_I2CD_BUS_RECOVER_CMD BIT(11) + +/* Command Bit */ +#define ASPEED_I2CD_M_STOP_CMD BIT(5) +#define ASPEED_I2CD_M_S_RX_CMD_LAST BIT(4) +#define ASPEED_I2CD_M_RX_CMD BIT(3) +#define ASPEED_I2CD_S_TX_CMD BIT(2) +#define ASPEED_I2CD_M_TX_CMD BIT(1) +#define ASPEED_I2CD_M_START_CMD BIT(0) + +/* 0x18 : I2CD Slave Device Address Register */ +#define ASPEED_I2CD_DEV_ADDR_MASK GENMASK(6, 0) + +enum aspeed_i2c_master_state { + ASPEED_I2C_MASTER_START, + ASPEED_I2C_MASTER_TX_FIRST, + ASPEED_I2C_MASTER_TX, + ASPEED_I2C_MASTER_RX_FIRST, + ASPEED_I2C_MASTER_RX, + ASPEED_I2C_MASTER_STOP, + ASPEED_I2C_MASTER_INACTIVE, +}; + +enum aspeed_i2c_slave_state { + ASPEED_I2C_SLAVE_START, + ASPEED_I2C_SLAVE_READ_REQUESTED, + ASPEED_I2C_SLAVE_READ_PROCESSED, + ASPEED_I2C_SLAVE_WRITE_REQUESTED, + ASPEED_I2C_SLAVE_WRITE_RECEIVED, + ASPEED_I2C_SLAVE_STOP, +}; + +struct aspeed_i2c_bus { + struct i2c_adapter adap; + struct device *dev; + void __iomem *base; + /* Synchronizes I/O mem access to base. */ + spinlock_t lock; + struct completion cmd_complete; + unsigned long parent_clk_frequency; + u32 bus_frequency; + /* Transaction state. */ + enum aspeed_i2c_master_state master_state; + struct i2c_msg *msgs; + size_t buf_index; + size_t msgs_index; + size_t msgs_count; + bool send_stop; + int cmd_err; + /* Protected only by i2c_lock_bus */ + int master_xfer_result; +#if IS_ENABLED(CONFIG_I2C_SLAVE) + struct i2c_client *slave; + enum aspeed_i2c_slave_state slave_state; +#endif /* CONFIG_I2C_SLAVE */ +}; + +static int aspeed_i2c_reset(struct aspeed_i2c_bus *bus); + +static int aspeed_i2c_recover_bus(struct aspeed_i2c_bus *bus) +{ + unsigned long time_left, flags; + int ret = 0; + u32 command; + + spin_lock_irqsave(&bus->lock, flags); + command = readl(bus->base + ASPEED_I2C_CMD_REG); + + if (command & ASPEED_I2CD_SDA_LINE_STS) { + /* Bus is idle: no recovery needed. */ + if (command & ASPEED_I2CD_SCL_LINE_STS) + goto out; + dev_dbg(bus->dev, "SCL hung (state %x), attempting recovery\n", + command); + + reinit_completion(&bus->cmd_complete); + writel(ASPEED_I2CD_M_STOP_CMD, bus->base + ASPEED_I2C_CMD_REG); + spin_unlock_irqrestore(&bus->lock, flags); + + time_left = wait_for_completion_timeout( + &bus->cmd_complete, bus->adap.timeout); + + spin_lock_irqsave(&bus->lock, flags); + if (time_left == 0) + goto reset_out; + else if (bus->cmd_err) + goto reset_out; + /* Recovery failed. */ + else if (!(readl(bus->base + ASPEED_I2C_CMD_REG) & + ASPEED_I2CD_SCL_LINE_STS)) + goto reset_out; + /* Bus error. */ + } else { + dev_dbg(bus->dev, "SDA hung (state %x), attempting recovery\n", + command); + + reinit_completion(&bus->cmd_complete); + /* Writes 1 to 8 SCL clock cycles until SDA is released. */ + writel(ASPEED_I2CD_BUS_RECOVER_CMD, + bus->base + ASPEED_I2C_CMD_REG); + spin_unlock_irqrestore(&bus->lock, flags); + + time_left = wait_for_completion_timeout( + &bus->cmd_complete, bus->adap.timeout); + + spin_lock_irqsave(&bus->lock, flags); + if (time_left == 0) + goto reset_out; + else if (bus->cmd_err) + goto reset_out; + /* Recovery failed. */ + else if (!(readl(bus->base + ASPEED_I2C_CMD_REG) & + ASPEED_I2CD_SDA_LINE_STS)) + goto reset_out; + } + +out: + spin_unlock_irqrestore(&bus->lock, flags); + + return ret; + +reset_out: + spin_unlock_irqrestore(&bus->lock, flags); + + return aspeed_i2c_reset(bus); +} + +#if IS_ENABLED(CONFIG_I2C_SLAVE) +static bool aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus) +{ + u32 command, irq_status, status_ack = 0; + struct i2c_client *slave = bus->slave; + bool irq_handled = true; + u8 value; + + spin_lock(&bus->lock); + if (!slave) { + irq_handled = false; + goto out; + } + + command = readl(bus->base + ASPEED_I2C_CMD_REG); + irq_status = readl(bus->base + ASPEED_I2C_INTR_STS_REG); + + /* Slave was requested, restart state machine. */ + if (irq_status & ASPEED_I2CD_INTR_SLAVE_MATCH) { + status_ack |= ASPEED_I2CD_INTR_SLAVE_MATCH; + bus->slave_state = ASPEED_I2C_SLAVE_START; + } + + /* Slave is not currently active, irq was for someone else. */ + if (bus->slave_state == ASPEED_I2C_SLAVE_STOP) { + irq_handled = false; + goto out; + } + + dev_dbg(bus->dev, "slave irq status 0x%08x, cmd 0x%08x\n", + irq_status, command); + + /* Slave was sent something. */ + if (irq_status & ASPEED_I2CD_INTR_RX_DONE) { + value = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> 8; + /* Handle address frame. */ + if (bus->slave_state == ASPEED_I2C_SLAVE_START) { + if (value & 0x1) + bus->slave_state = + ASPEED_I2C_SLAVE_READ_REQUESTED; + else + bus->slave_state = + ASPEED_I2C_SLAVE_WRITE_REQUESTED; + } + status_ack |= ASPEED_I2CD_INTR_RX_DONE; + } + + /* Slave was asked to stop. */ + if (irq_status & ASPEED_I2CD_INTR_NORMAL_STOP) { + status_ack |= ASPEED_I2CD_INTR_NORMAL_STOP; + bus->slave_state = ASPEED_I2C_SLAVE_STOP; + } + if (irq_status & ASPEED_I2CD_INTR_TX_NAK) { + status_ack |= ASPEED_I2CD_INTR_TX_NAK; + bus->slave_state = ASPEED_I2C_SLAVE_STOP; + } + + switch (bus->slave_state) { + case ASPEED_I2C_SLAVE_READ_REQUESTED: + if (irq_status & ASPEED_I2CD_INTR_TX_ACK) + dev_err(bus->dev, "Unexpected ACK on read request.\n"); + bus->slave_state = ASPEED_I2C_SLAVE_READ_PROCESSED; + + i2c_slave_event(slave, I2C_SLAVE_READ_REQUESTED, &value); + writel(value, bus->base + ASPEED_I2C_BYTE_BUF_REG); + writel(ASPEED_I2CD_S_TX_CMD, bus->base + ASPEED_I2C_CMD_REG); + break; + case ASPEED_I2C_SLAVE_READ_PROCESSED: + status_ack |= ASPEED_I2CD_INTR_TX_ACK; + if (!(irq_status & ASPEED_I2CD_INTR_TX_ACK)) + dev_err(bus->dev, + "Expected ACK after processed read.\n"); + i2c_slave_event(slave, I2C_SLAVE_READ_PROCESSED, &value); + writel(value, bus->base + ASPEED_I2C_BYTE_BUF_REG); + writel(ASPEED_I2CD_S_TX_CMD, bus->base + ASPEED_I2C_CMD_REG); + break; + case ASPEED_I2C_SLAVE_WRITE_REQUESTED: + bus->slave_state = ASPEED_I2C_SLAVE_WRITE_RECEIVED; + i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value); + break; + case ASPEED_I2C_SLAVE_WRITE_RECEIVED: + i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED, &value); + break; + case ASPEED_I2C_SLAVE_STOP: + i2c_slave_event(slave, I2C_SLAVE_STOP, &value); + break; + default: + dev_err(bus->dev, "unhandled slave_state: %d\n", + bus->slave_state); + break; + } + + if (status_ack != irq_status) + dev_err(bus->dev, + "irq handled != irq. expected %x, but was %x\n", + irq_status, status_ack); + writel(status_ack, bus->base + ASPEED_I2C_INTR_STS_REG); + +out: + spin_unlock(&bus->lock); + return irq_handled; +} +#endif /* CONFIG_I2C_SLAVE */ + +/* precondition: bus.lock has been acquired. */ +static void aspeed_i2c_do_start(struct aspeed_i2c_bus *bus) +{ + u32 command = ASPEED_I2CD_M_START_CMD | ASPEED_I2CD_M_TX_CMD; + struct i2c_msg *msg = &bus->msgs[bus->msgs_index]; + u8 slave_addr = msg->addr << 1; + + bus->master_state = ASPEED_I2C_MASTER_START; + bus->buf_index = 0; + + if (msg->flags & I2C_M_RD) { + slave_addr |= 1; + command |= ASPEED_I2CD_M_RX_CMD; + /* Need to let the hardware know to NACK after RX. */ + if (msg->len == 1 && !(msg->flags & I2C_M_RECV_LEN)) + command |= ASPEED_I2CD_M_S_RX_CMD_LAST; + } + + writel(slave_addr, bus->base + ASPEED_I2C_BYTE_BUF_REG); + writel(command, bus->base + ASPEED_I2C_CMD_REG); +} + +/* precondition: bus.lock has been acquired. */ +static void aspeed_i2c_do_stop(struct aspeed_i2c_bus *bus) +{ + bus->master_state = ASPEED_I2C_MASTER_STOP; + writel(ASPEED_I2CD_M_STOP_CMD, bus->base + ASPEED_I2C_CMD_REG); +} + +/* precondition: bus.lock has been acquired. */ +static void aspeed_i2c_next_msg_or_stop(struct aspeed_i2c_bus *bus) +{ + if (bus->msgs_index + 1 < bus->msgs_count) { + bus->msgs_index++; + aspeed_i2c_do_start(bus); + } else { + aspeed_i2c_do_stop(bus); + } +} + +static int aspeed_i2c_is_irq_error(u32 irq_status) +{ + if (irq_status & ASPEED_I2CD_INTR_ARBIT_LOSS) + return -EAGAIN; + if (irq_status & (ASPEED_I2CD_INTR_SDA_DL_TIMEOUT | + ASPEED_I2CD_INTR_SCL_TIMEOUT)) + return -EBUSY; + if (irq_status & (ASPEED_I2CD_INTR_ABNORMAL)) + return -EPROTO; + + return 0; +} + +static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus) +{ + u32 irq_status, status_ack = 0, command = 0; + struct i2c_msg *msg; + u8 recv_byte; + int ret; + + spin_lock(&bus->lock); + irq_status = readl(bus->base + ASPEED_I2C_INTR_STS_REG); + /* Ack all interrupt bits. */ + writel(irq_status, bus->base + ASPEED_I2C_INTR_STS_REG); + + if (irq_status & ASPEED_I2CD_INTR_BUS_RECOVER_DONE) { + bus->master_state = ASPEED_I2C_MASTER_INACTIVE; + status_ack |= ASPEED_I2CD_INTR_BUS_RECOVER_DONE; + goto out_complete; + } + + /* + * We encountered an interrupt that reports an error: the hardware + * should clear the command queue effectively taking us back to the + * INACTIVE state. + */ + ret = aspeed_i2c_is_irq_error(irq_status); + if (ret < 0) { + dev_dbg(bus->dev, "received error interrupt: 0x%08x", + irq_status); + bus->cmd_err = ret; + bus->master_state = ASPEED_I2C_MASTER_INACTIVE; + goto out_complete; + } + + /* We are in an invalid state; reset bus to a known state. */ + if (!bus->msgs && bus->master_state != ASPEED_I2C_MASTER_STOP) { + dev_err(bus->dev, "bus in unknown state"); + bus->cmd_err = -EIO; + aspeed_i2c_do_stop(bus); + goto out_no_complete; + } + msg = &bus->msgs[bus->msgs_index]; + + /* + * START is a special case because we still have to handle a subsequent + * TX or RX immediately after we handle it, so we handle it here and + * then update the state and handle the new state below. + */ + if (bus->master_state == ASPEED_I2C_MASTER_START) { + if (unlikely(!(irq_status & ASPEED_I2CD_INTR_TX_ACK))) { + pr_devel("no slave present at %02x", msg->addr); + status_ack |= ASPEED_I2CD_INTR_TX_NAK; + bus->cmd_err = -ENXIO; + aspeed_i2c_do_stop(bus); + goto out_no_complete; + } + status_ack |= ASPEED_I2CD_INTR_TX_ACK; + if (msg->len == 0) { /* SMBUS_QUICK */ + aspeed_i2c_do_stop(bus); + goto out_no_complete; + } + if (msg->flags & I2C_M_RD) + bus->master_state = ASPEED_I2C_MASTER_RX_FIRST; + else + bus->master_state = ASPEED_I2C_MASTER_TX_FIRST; + } + + switch (bus->master_state) { + case ASPEED_I2C_MASTER_TX: + if (unlikely(irq_status & ASPEED_I2CD_INTR_TX_NAK)) { + dev_dbg(bus->dev, "slave NACKed TX"); + status_ack |= ASPEED_I2CD_INTR_TX_NAK; + goto error_and_stop; + } else if (unlikely(!(irq_status & ASPEED_I2CD_INTR_TX_ACK))) { + dev_err(bus->dev, "slave failed to ACK TX"); + goto error_and_stop; + } + status_ack |= ASPEED_I2CD_INTR_TX_ACK; + /* fallthrough intended */ + case ASPEED_I2C_MASTER_TX_FIRST: + if (bus->buf_index < msg->len) { + bus->master_state = ASPEED_I2C_MASTER_TX; + writel(msg->buf[bus->buf_index++], + bus->base + ASPEED_I2C_BYTE_BUF_REG); + writel(ASPEED_I2CD_M_TX_CMD, + bus->base + ASPEED_I2C_CMD_REG); + } else { + aspeed_i2c_next_msg_or_stop(bus); + } + goto out_no_complete; + case ASPEED_I2C_MASTER_RX_FIRST: + /* RX may not have completed yet (only address cycle) */ + if (!(irq_status & ASPEED_I2CD_INTR_RX_DONE)) + goto out_no_complete; + /* fallthrough intended */ + case ASPEED_I2C_MASTER_RX: + if (unlikely(!(irq_status & ASPEED_I2CD_INTR_RX_DONE))) { + dev_err(bus->dev, "master failed to RX"); + goto error_and_stop; + } + status_ack |= ASPEED_I2CD_INTR_RX_DONE; + + recv_byte = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> 8; + msg->buf[bus->buf_index++] = recv_byte; + + if (msg->flags & I2C_M_RECV_LEN) { + if (unlikely(recv_byte > I2C_SMBUS_BLOCK_MAX)) { + bus->cmd_err = -EPROTO; + aspeed_i2c_do_stop(bus); + goto out_no_complete; + } + msg->len = recv_byte + + ((msg->flags & I2C_CLIENT_PEC) ? 2 : 1); + msg->flags &= ~I2C_M_RECV_LEN; + } + + if (bus->buf_index < msg->len) { + bus->master_state = ASPEED_I2C_MASTER_RX; + command = ASPEED_I2CD_M_RX_CMD; + if (bus->buf_index + 1 == msg->len) + command |= ASPEED_I2CD_M_S_RX_CMD_LAST; + writel(command, bus->base + ASPEED_I2C_CMD_REG); + } else { + aspeed_i2c_next_msg_or_stop(bus); + } + goto out_no_complete; + case ASPEED_I2C_MASTER_STOP: + if (unlikely(!(irq_status & ASPEED_I2CD_INTR_NORMAL_STOP))) { + dev_err(bus->dev, "master failed to STOP"); + bus->cmd_err = -EIO; + /* Do not STOP as we have already tried. */ + } else { + status_ack |= ASPEED_I2CD_INTR_NORMAL_STOP; + } + + bus->master_state = ASPEED_I2C_MASTER_INACTIVE; + goto out_complete; + case ASPEED_I2C_MASTER_INACTIVE: + dev_err(bus->dev, + "master received interrupt 0x%08x, but is inactive", + irq_status); + bus->cmd_err = -EIO; + /* Do not STOP as we should be inactive. */ + goto out_complete; + default: + WARN(1, "unknown master state\n"); + bus->master_state = ASPEED_I2C_MASTER_INACTIVE; + bus->cmd_err = -EINVAL; + goto out_complete; + } +error_and_stop: + bus->cmd_err = -EIO; + aspeed_i2c_do_stop(bus); + goto out_no_complete; +out_complete: + bus->msgs = NULL; + if (bus->cmd_err) + bus->master_xfer_result = bus->cmd_err; + else + bus->master_xfer_result = bus->msgs_index + 1; + complete(&bus->cmd_complete); +out_no_complete: + if (irq_status != status_ack) + dev_err(bus->dev, + "irq handled != irq. expected 0x%08x, but was 0x%08x\n", + irq_status, status_ack); + spin_unlock(&bus->lock); + return !!irq_status; +} + +static irqreturn_t aspeed_i2c_bus_irq(int irq, void *dev_id) +{ + struct aspeed_i2c_bus *bus = dev_id; + +#if IS_ENABLED(CONFIG_I2C_SLAVE) + if (aspeed_i2c_slave_irq(bus)) { + dev_dbg(bus->dev, "irq handled by slave.\n"); + return IRQ_HANDLED; + } +#endif /* CONFIG_I2C_SLAVE */ + + return aspeed_i2c_master_irq(bus) ? IRQ_HANDLED : IRQ_NONE; +} + +static int aspeed_i2c_master_xfer(struct i2c_adapter *adap, + struct i2c_msg *msgs, int num) +{ + struct aspeed_i2c_bus *bus = i2c_get_adapdata(adap); + unsigned long time_left, flags; + int ret = 0; + + spin_lock_irqsave(&bus->lock, flags); + bus->cmd_err = 0; + + /* If bus is busy, attempt recovery. We assume a single master + * environment. + */ + if (readl(bus->base + ASPEED_I2C_CMD_REG) & ASPEED_I2CD_BUS_BUSY_STS) { + spin_unlock_irqrestore(&bus->lock, flags); + ret = aspeed_i2c_recover_bus(bus); + if (ret) + return ret; + spin_lock_irqsave(&bus->lock, flags); + } + + bus->cmd_err = 0; + bus->msgs = msgs; + bus->msgs_index = 0; + bus->msgs_count = num; + + reinit_completion(&bus->cmd_complete); + aspeed_i2c_do_start(bus); + spin_unlock_irqrestore(&bus->lock, flags); + + time_left = wait_for_completion_timeout(&bus->cmd_complete, + bus->adap.timeout); + + if (time_left == 0) + return -ETIMEDOUT; + else + return bus->master_xfer_result; +} + +static u32 aspeed_i2c_functionality(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA; +} + +#if IS_ENABLED(CONFIG_I2C_SLAVE) +/* precondition: bus.lock has been acquired. */ +static void __aspeed_i2c_reg_slave(struct aspeed_i2c_bus *bus, u16 slave_addr) +{ + u32 addr_reg_val, func_ctrl_reg_val; + + /* Set slave addr. */ + addr_reg_val = readl(bus->base + ASPEED_I2C_DEV_ADDR_REG); + addr_reg_val &= ~ASPEED_I2CD_DEV_ADDR_MASK; + addr_reg_val |= slave_addr & ASPEED_I2CD_DEV_ADDR_MASK; + writel(addr_reg_val, bus->base + ASPEED_I2C_DEV_ADDR_REG); + + /* Turn on slave mode. */ + func_ctrl_reg_val = readl(bus->base + ASPEED_I2C_FUN_CTRL_REG); + func_ctrl_reg_val |= ASPEED_I2CD_SLAVE_EN; + writel(func_ctrl_reg_val, bus->base + ASPEED_I2C_FUN_CTRL_REG); +} + +static int aspeed_i2c_reg_slave(struct i2c_client *client) +{ + struct aspeed_i2c_bus *bus = i2c_get_adapdata(client->adapter); + unsigned long flags; + + spin_lock_irqsave(&bus->lock, flags); + if (bus->slave) { + spin_unlock_irqrestore(&bus->lock, flags); + return -EINVAL; + } + + __aspeed_i2c_reg_slave(bus, client->addr); + + bus->slave = client; + bus->slave_state = ASPEED_I2C_SLAVE_STOP; + spin_unlock_irqrestore(&bus->lock, flags); + |