diff options
| -rw-r--r-- | drivers/i2c/busses/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/i2c/busses/Makefile | 1 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-npcm7xx.c | 1736 |
3 files changed, 1746 insertions, 0 deletions
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 14e2e93a5698..735bf31a3fdf 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -794,6 +794,15 @@ config I2C_NOMADIK I2C interface from ST-Ericsson's Nomadik and Ux500 architectures, as well as the STA2X11 PCIe I/O HUB. +config I2C_NPCM7XX + tristate "Nuvoton I2C Controller" + depends on ARCH_NPCM7XX || COMPILE_TEST + help + If you say yes to this option, support will be included for the + Nuvoton I2C controller, which is available on the NPCM7xx BMC + controller. + Driver can also support slave mode (select I2C_SLAVE). + config I2C_OCORES tristate "OpenCores I2C Controller" help diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index e18497fb85c5..306d5dc3f417 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -80,6 +80,7 @@ obj-$(CONFIG_I2C_MT7621) += i2c-mt7621.o obj-$(CONFIG_I2C_MV64XXX) += i2c-mv64xxx.o obj-$(CONFIG_I2C_MXS) += i2c-mxs.o obj-$(CONFIG_I2C_NOMADIK) += i2c-nomadik.o +obj-$(CONFIG_I2C_NPCM7XX) += i2c-npcm7xx.o obj-$(CONFIG_I2C_OCORES) += i2c-ocores.o obj-$(CONFIG_I2C_OMAP) += i2c-omap.o obj-$(CONFIG_I2C_OWL) += i2c-owl.o diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c new file mode 100644 index 000000000000..018abf8dda7e --- /dev/null +++ b/drivers/i2c/busses/i2c-npcm7xx.c @@ -0,0 +1,1736 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Nuvoton NPCM7xx I2C Controller driver + * + * Copyright (C) 2020 Nuvoton Technologies tali.perry@nuvoton.com + */ +#include <linux/bitfield.h> +#include <linux/clk.h> +#include <linux/debugfs.h> +#include <linux/errno.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/iopoll.h> +#include <linux/irq.h> +#include <linux/jiffies.h> +#include <linux/kernel.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +enum i2c_mode { + I2C_MASTER, + I2C_SLAVE, +}; + +/* + * External I2C Interface driver xfer indication values, which indicate status + * of the bus. + */ +enum i2c_state_ind { + I2C_NO_STATUS_IND = 0, + I2C_SLAVE_RCV_IND, + I2C_SLAVE_XMIT_IND, + I2C_SLAVE_XMIT_MISSING_DATA_IND, + I2C_SLAVE_RESTART_IND, + I2C_SLAVE_DONE_IND, + I2C_MASTER_DONE_IND, + I2C_NACK_IND, + I2C_BUS_ERR_IND, + I2C_WAKE_UP_IND, + I2C_BLOCK_BYTES_ERR_IND, + I2C_SLAVE_RCV_MISSING_DATA_IND, +}; + +/* + * Operation type values (used to define the operation currently running) + * module is interrupt driven, on each interrupt the current operation is + * checked to see if the module is currently reading or writing. + */ +enum i2c_oper { + I2C_NO_OPER = 0, + I2C_WRITE_OPER, + I2C_READ_OPER, +}; + +/* I2C Bank (module had 2 banks of registers) */ +enum i2c_bank { + I2C_BANK_0 = 0, + I2C_BANK_1, +}; + +/* Internal I2C states values (for the I2C module state machine). */ +enum i2c_state { + I2C_DISABLE = 0, + I2C_IDLE, + I2C_MASTER_START, + I2C_SLAVE_MATCH, + I2C_OPER_STARTED, + I2C_STOP_PENDING, +}; + +/* init register and default value required to enable module */ +#define NPCM_I2CSEGCTL 0xE4 +#define NPCM_I2CSEGCTL_INIT_VAL 0x0333F000 + +/* Common regs */ +#define NPCM_I2CSDA 0x00 +#define NPCM_I2CST 0x02 +#define NPCM_I2CCST 0x04 +#define NPCM_I2CCTL1 0x06 +#define NPCM_I2CADDR1 0x08 +#define NPCM_I2CCTL2 0x0A +#define NPCM_I2CADDR2 0x0C +#define NPCM_I2CCTL3 0x0E +#define NPCM_I2CCST2 0x18 +#define NPCM_I2CCST3 0x19 +#define I2C_VER 0x1F + +/*BANK0 regs*/ +#define NPCM_I2CADDR3 0x10 +#define NPCM_I2CADDR7 0x11 +#define NPCM_I2CADDR4 0x12 +#define NPCM_I2CADDR8 0x13 +#define NPCM_I2CADDR5 0x14 +#define NPCM_I2CADDR9 0x15 +#define NPCM_I2CADDR6 0x16 +#define NPCM_I2CADDR10 0x17 + +#define NPCM_I2CCTL4 0x1A +#define NPCM_I2CCTL5 0x1B +#define NPCM_I2CSCLLT 0x1C /* SCL Low Time */ +#define NPCM_I2CFIF_CTL 0x1D /* FIFO Control */ +#define NPCM_I2CSCLHT 0x1E /* SCL High Time */ + +/* BANK 1 regs */ +#define NPCM_I2CFIF_CTS 0x10 /* Both FIFOs Control and Status */ +#define NPCM_I2CTXF_CTL 0x12 /* Tx-FIFO Control */ +#define NPCM_I2CT_OUT 0x14 /* Bus T.O. */ +#define NPCM_I2CPEC 0x16 /* PEC Data */ +#define NPCM_I2CTXF_STS 0x1A /* Tx-FIFO Status */ +#define NPCM_I2CRXF_STS 0x1C /* Rx-FIFO Status */ +#define NPCM_I2CRXF_CTL 0x1E /* Rx-FIFO Control */ + +/* NPCM_I2CST reg fields */ +#define NPCM_I2CST_XMIT BIT(0) +#define NPCM_I2CST_MASTER BIT(1) +#define NPCM_I2CST_NMATCH BIT(2) +#define NPCM_I2CST_STASTR BIT(3) +#define NPCM_I2CST_NEGACK BIT(4) +#define NPCM_I2CST_BER BIT(5) +#define NPCM_I2CST_SDAST BIT(6) +#define NPCM_I2CST_SLVSTP BIT(7) + +/* NPCM_I2CCST reg fields */ +#define NPCM_I2CCST_BUSY BIT(0) +#define NPCM_I2CCST_BB BIT(1) +#define NPCM_I2CCST_MATCH BIT(2) +#define NPCM_I2CCST_GCMATCH BIT(3) +#define NPCM_I2CCST_TSDA BIT(4) +#define NPCM_I2CCST_TGSCL BIT(5) +#define NPCM_I2CCST_MATCHAF BIT(6) +#define NPCM_I2CCST_ARPMATCH BIT(7) + +/* NPCM_I2CCTL1 reg fields */ +#define NPCM_I2CCTL1_START BIT(0) +#define NPCM_I2CCTL1_STOP BIT(1) +#define NPCM_I2CCTL1_INTEN BIT(2) +#define NPCM_I2CCTL1_EOBINTE BIT(3) +#define NPCM_I2CCTL1_ACK BIT(4) +#define NPCM_I2CCTL1_GCMEN BIT(5) +#define NPCM_I2CCTL1_NMINTE BIT(6) +#define NPCM_I2CCTL1_STASTRE BIT(7) + +/* RW1S fields (inside a RW reg): */ +#define NPCM_I2CCTL1_RWS \ + (NPCM_I2CCTL1_START | NPCM_I2CCTL1_STOP | NPCM_I2CCTL1_ACK) + +/* npcm_i2caddr reg fields */ +#define NPCM_I2CADDR_A GENMASK(6, 0) +#define NPCM_I2CADDR_SAEN BIT(7) + +/* NPCM_I2CCTL2 reg fields */ +#define I2CCTL2_ENABLE BIT(0) +#define I2CCTL2_SCLFRQ6_0 GENMASK(7, 1) + +/* NPCM_I2CCTL3 reg fields */ +#define I2CCTL3_SCLFRQ8_7 GENMASK(1, 0) +#define I2CCTL3_ARPMEN BIT(2) +#define I2CCTL3_IDL_START BIT(3) +#define I2CCTL3_400K_MODE BIT(4) +#define I2CCTL3_BNK_SEL BIT(5) +#define I2CCTL3_SDA_LVL BIT(6) +#define I2CCTL3_SCL_LVL BIT(7) + +/* NPCM_I2CCST2 reg fields */ +#define NPCM_I2CCST2_MATCHA1F BIT(0) +#define NPCM_I2CCST2_MATCHA2F BIT(1) +#define NPCM_I2CCST2_MATCHA3F BIT(2) +#define NPCM_I2CCST2_MATCHA4F BIT(3) +#define NPCM_I2CCST2_MATCHA5F BIT(4) +#define NPCM_I2CCST2_MATCHA6F BIT(5) +#define NPCM_I2CCST2_MATCHA7F BIT(5) +#define NPCM_I2CCST2_INTSTS BIT(7) + +/* NPCM_I2CCST3 reg fields */ +#define NPCM_I2CCST3_MATCHA8F BIT(0) +#define NPCM_I2CCST3_MATCHA9F BIT(1) +#define NPCM_I2CCST3_MATCHA10F BIT(2) +#define NPCM_I2CCST3_EO_BUSY BIT(7) + +/* NPCM_I2CCTL4 reg fields */ +#define I2CCTL4_HLDT GENMASK(5, 0) +#define I2CCTL4_LVL_WE BIT(7) + +/* NPCM_I2CCTL5 reg fields */ +#define I2CCTL5_DBNCT GENMASK(3, 0) + +/* NPCM_I2CFIF_CTS reg fields */ +#define NPCM_I2CFIF_CTS_RXF_TXE BIT(1) +#define NPCM_I2CFIF_CTS_RFTE_IE BIT(3) +#define NPCM_I2CFIF_CTS_CLR_FIFO BIT(6) +#define NPCM_I2CFIF_CTS_SLVRSTR BIT(7) + +/* NPCM_I2CTXF_CTL reg fields */ +#define NPCM_I2CTXF_CTL_TX_THR GENMASK(4, 0) +#define NPCM_I2CTXF_CTL_THR_TXIE BIT(6) + +/* NPCM_I2CT_OUT reg fields */ +#define NPCM_I2CT_OUT_TO_CKDIV GENMASK(5, 0) +#define NPCM_I2CT_OUT_T_OUTIE BIT(6) +#define NPCM_I2CT_OUT_T_OUTST BIT(7) + +/* NPCM_I2CTXF_STS reg fields */ +#define NPCM_I2CTXF_STS_TX_BYTES GENMASK(4, 0) +#define NPCM_I2CTXF_STS_TX_THST BIT(6) + +/* NPCM_I2CRXF_STS reg fields */ +#define NPCM_I2CRXF_STS_RX_BYTES GENMASK(4, 0) +#define NPCM_I2CRXF_STS_RX_THST BIT(6) + +/* NPCM_I2CFIF_CTL reg fields */ +#define NPCM_I2CFIF_CTL_FIFO_EN BIT(4) + +/* NPCM_I2CRXF_CTL reg fields */ +#define NPCM_I2CRXF_CTL_RX_THR GENMASK(4, 0) +#define NPCM_I2CRXF_CTL_LAST_PEC BIT(5) +#define NPCM_I2CRXF_CTL_THR_RXIE BIT(6) + +#define I2C_HW_FIFO_SIZE 16 + +/* I2C_VER reg fields */ +#define I2C_VER_VERSION GENMASK(6, 0) +#define I2C_VER_FIFO_EN BIT(7) + +/* stall/stuck timeout in us */ +#define DEFAULT_STALL_COUNT 25 + +/* SCLFRQ field position */ +#define SCLFRQ_0_TO_6 GENMASK(6, 0) +#define SCLFRQ_7_TO_8 GENMASK(8, 7) + +/* supported clk settings. values in Hz. */ +#define I2C_FREQ_MIN_HZ 10000 +#define I2C_FREQ_MAX_HZ I2C_MAX_FAST_MODE_PLUS_FREQ + +/* Status of one I2C module */ +struct npcm_i2c { + struct i2c_adapter adap; + struct device *dev; + unsigned char __iomem *reg; + spinlock_t lock; /* IRQ synchronization */ + struct completion cmd_complete; + int cmd_err; + struct i2c_msg *msgs; + int msgs_num; + int num; + u32 apb_clk; + struct i2c_bus_recovery_info rinfo; + enum i2c_state state; + enum i2c_oper operation; + enum i2c_mode master_or_slave; + enum i2c_state_ind stop_ind; + u8 dest_addr; + u8 *rd_buf; + u16 rd_size; + u16 rd_ind; + u8 *wr_buf; + u16 wr_size; + u16 wr_ind; + bool fifo_use; + u16 PEC_mask; /* PEC bit mask per slave address */ + bool PEC_use; + bool read_block_use; + unsigned long int_time_stamp; + unsigned long bus_freq; /* in Hz */ + struct dentry *debugfs; /* debugfs device directory */ + u64 ber_cnt; + u64 rec_succ_cnt; + u64 rec_fail_cnt; + u64 nack_cnt; + u64 timeout_cnt; +}; + +static inline void npcm_i2c_select_bank(struct npcm_i2c *bus, + enum i2c_bank bank) +{ + u8 i2cctl3 = ioread8(bus->reg + NPCM_I2CCTL3); + + if (bank == I2C_BANK_0) + i2cctl3 = i2cctl3 & ~I2CCTL3_BNK_SEL; + else + i2cctl3 = i2cctl3 | I2CCTL3_BNK_SEL; + iowrite8(i2cctl3, bus->reg + NPCM_I2CCTL3); +} + +static void npcm_i2c_init_params(struct npcm_i2c *bus) +{ + bus->stop_ind = I2C_NO_STATUS_IND; + bus->rd_size = 0; + bus->wr_size = 0; + bus->rd_ind = 0; + bus->wr_ind = 0; + bus->read_block_use = false; + bus->int_time_stamp = 0; + bus->PEC_use = false; + bus->PEC_mask = 0; +} + +static inline void npcm_i2c_wr_byte(struct npcm_i2c *bus, u8 data) +{ + iowrite8(data, bus->reg + NPCM_I2CSDA); +} + +static inline u8 npcm_i2c_rd_byte(struct npcm_i2c *bus) +{ + return ioread8(bus->reg + NPCM_I2CSDA); +} + +static int npcm_i2c_get_SCL(struct i2c_adapter *_adap) +{ + struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap); + + return !!(I2CCTL3_SCL_LVL & ioread32(bus->reg + NPCM_I2CCTL3)); +} + +static int npcm_i2c_get_SDA(struct i2c_adapter *_adap) +{ + struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap); + + return !!(I2CCTL3_SDA_LVL & ioread32(bus->reg + NPCM_I2CCTL3)); +} + +static inline u16 npcm_i2c_get_index(struct npcm_i2c *bus) +{ + if (bus->operation == I2C_READ_OPER) + return bus->rd_ind; + if (bus->operation == I2C_WRITE_OPER) + return bus->wr_ind; + return 0; +} + +/* quick protocol (just address) */ +static inline bool npcm_i2c_is_quick(struct npcm_i2c *bus) +{ + return bus->wr_size == 0 && bus->rd_size == 0; +} + +static void npcm_i2c_disable(struct npcm_i2c *bus) +{ + u8 i2cctl2; + + /* Disable module */ + i2cctl2 = ioread8(bus->reg + NPCM_I2CCTL2); + i2cctl2 = i2cctl2 & ~I2CCTL2_ENABLE; + iowrite8(i2cctl2, bus->reg + NPCM_I2CCTL2); + + bus->state = I2C_DISABLE; +} + +static void npcm_i2c_enable(struct npcm_i2c *bus) +{ + u8 i2cctl2 = ioread8(bus->reg + NPCM_I2CCTL2); + + i2cctl2 = i2cctl2 | I2CCTL2_ENABLE; + iowrite8(i2cctl2, bus->reg + NPCM_I2CCTL2); + bus->state = I2C_IDLE; +} + +/* enable\disable end of busy (EOB) interrupts */ +static inline void npcm_i2c_eob_int(struct npcm_i2c *bus, bool enable) +{ + u8 val; + + /* Clear EO_BUSY pending bit: */ + val = ioread8(bus->reg + NPCM_I2CCST3); + val = val | NPCM_I2CCST3_EO_BUSY; + iowrite8(val, bus->reg + NPCM_I2CCST3); + + val = ioread8(bus->reg + NPCM_I2CCTL1); + val &= ~NPCM_I2CCTL1_RWS; + if (enable) + val |= NPCM_I2CCTL1_EOBINTE; + else + val &= ~NPCM_I2CCTL1_EOBINTE; + iowrite8(val, bus->reg + NPCM_I2CCTL1); +} + +static inline bool npcm_i2c_tx_fifo_empty(struct npcm_i2c *bus) +{ + u8 tx_fifo_sts; + + tx_fifo_sts = ioread8(bus->reg + NPCM_I2CTXF_STS); + /* check if TX FIFO is not empty */ + if ((tx_fifo_sts & NPCM_I2CTXF_STS_TX_BYTES) == 0) + return false; + + /* check if TX FIFO status bit is set: */ + return !!FIELD_GET(NPCM_I2CTXF_STS_TX_THST, tx_fifo_sts); +} + +static inline bool npcm_i2c_rx_fifo_full(struct npcm_i2c *bus) +{ + u8 rx_fifo_sts; + + rx_fifo_sts = ioread8(bus->reg + NPCM_I2CRXF_STS); + /* check if RX FIFO is not empty: */ + if ((rx_fifo_sts & NPCM_I2CRXF_STS_RX_BYTES) == 0) + return false; + + /* check if rx fifo full status is set: */ + return !!FIELD_GET(NPCM_I2CRXF_STS_RX_THST, rx_fifo_sts); +} + +static inline void npcm_i2c_clear_fifo_int(struct npcm_i2c *bus) +{ + u8 val; + + val = ioread8(bus->reg + NPCM_I2CFIF_CTS); + val = (val & NPCM_I2CFIF_CTS_SLVRSTR) | NPCM_I2CFIF_CTS_RXF_TXE; + iowrite8(val, bus->reg + NPCM_I2CFIF_CTS); +} + +static inline void npcm_i2c_clear_tx_fifo(struct npcm_i2c *bus) +{ + u8 val; + + val = ioread8(bus->reg + NPCM_I2CTXF_STS); + val = val | NPCM_I2CTXF_STS_TX_THST; + iowrite8(val, bus->reg + NPCM_I2CTXF_STS); +} + +static inline void npcm_i2c_clear_rx_fifo(struct npcm_i2c *bus) +{ + u8 val; + + val = ioread8(bus->reg + NPCM_I2CRXF_STS); + val = val | NPCM_I2CRXF_STS_RX_THST; + iowrite8(val, bus->reg + NPCM_I2CRXF_STS); +} + +static void npcm_i2c_int_enable(struct npcm_i2c *bus, bool enable) +{ + u8 val; + + val = ioread8(bus->reg + NPCM_I2CCTL1); + val &= ~NPCM_I2CCTL1_RWS; + if (enable) + val |= NPCM_I2CCTL1_INTEN; + else + val &= ~NPCM_I2CCTL1_INTEN; + iowrite8(val, bus->reg + NPCM_I2CCTL1); +} + +static inline void npcm_i2c_master_start(struct npcm_i2c *bus) +{ + u8 val; + + val = ioread8(bus->reg + NPCM_I2CCTL1); + val &= ~(NPCM_I2CCTL1_STOP | NPCM_I2CCTL1_ACK); + val |= NPCM_I2CCTL1_START; + iowrite8(val, bus->reg + NPCM_I2CCTL1); +} + +static inline void npcm_i2c_master_stop(struct npcm_i2c *bus) +{ + u8 val; + + /* + * override HW issue: I2C may fail to supply stop condition in Master + * Write operation. + * Need to delay at least 5 us from the last int, before issueing a stop + */ + udelay(10); /* function called from interrupt, can't sleep */ + val = ioread8(bus->reg + NPCM_I2CCTL1); + val &= ~(NPCM_I2CCTL1_START | NPCM_I2CCTL1_ACK); + val |= NPCM_I2CCTL1_STOP; + iowrite8(val, bus->reg + NPCM_I2CCTL1); + + if (!bus->fifo_use) + return; + + npcm_i2c_select_bank(bus, I2C_BANK_1); + + if (bus->operation == I2C_READ_OPER) + npcm_i2c_clear_rx_fifo(bus); + else + npcm_i2c_clear_tx_fifo(bus); + npcm_i2c_clear_fifo_int(bus); + iowrite8(0, bus->reg + NPCM_I2CTXF_CTL); +} + +static inline void npcm_i2c_stall_after_start(struct npcm_i2c *bus, bool stall) +{ + u8 val; + + val = ioread8(bus->reg + NPCM_I2CCTL1); + val &= ~NPCM_I2CCTL1_RWS; + if (stall) + val |= NPCM_I2CCTL1_STASTRE; + else + val &= ~NPCM_I2CCTL1_STASTRE; + iowrite8(val, bus->reg + NPCM_I2CCTL1); +} + +static inline void npcm_i2c_nack(struct npcm_i2c *bus) +{ + u8 val; + + val = ioread8(bus->reg + NPCM_I2CCTL1); + val &= ~(NPCM_I2CCTL1_STOP | NPCM_I2CCTL1_START); + val |= NPCM_I2CCTL1_ACK; + iowrite8(val, bus->reg + NPCM_I2CCTL1); +} + +static void npcm_i2c_reset(struct npcm_i2c *bus) +{ + /* + * Save I2CCTL1 relevant bits. It is being cleared when the module + * is disabled. + */ + u8 i2cctl1; + + i2cctl1 = ioread8(bus->reg + NPCM_I2CCTL1); + + npcm_i2c_disable(bus); + npcm_i2c_enable(bus); + + /* Restore NPCM_I2CCTL1 Status */ + i2cctl1 &= ~NPCM_I2CCTL1_RWS; + iowrite8(i2cctl1, bus->reg + NPCM_I2CCTL1); + + /* Clear BB (BUS BUSY) bit */ + iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST); + iowrite8(0xFF, bus->reg + NPCM_I2CST); + + /* Clear EOB bit */ + iowrite8(NPCM_I2CCST3_EO_BUSY, bus->reg + NPCM_I2CCST3); + + /* Clear all fifo bits: */ + iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO, bus->reg + NPCM_I2CFIF_CTS); + + bus->state = I2C_IDLE; +} + +static inline bool npcm_i2c_is_master(struct npcm_i2c *bus) +{ + return !!FIELD_GET(NPCM_I2CST_MASTER, ioread8(bus->reg + NPCM_I2CST)); +} + +static void npcm_i2c_callback(struct npcm_i2c *bus, + enum i2c_state_ind op_status, u16 info) +{ + struct i2c_msg *msgs; + int msgs_num; + + msgs = bus->msgs; + msgs_num = bus->msgs_num; + /* + * check that transaction was not timed-out, and msgs still + * holds a valid value. + */ + if (!msgs) + return; + + if (completion_done(&bus->cmd_complete)) + return; + + switch (op_status) { + case I2C_MASTER_DONE_IND: + bus->cmd_err = bus->msgs_num; + fallthrough; + case I2C_BLOCK_BYTES_ERR_IND: + /* Master tx finished and all transmit bytes were sent */ + if (bus->msgs) { + if (msgs[0].flags & I2C_M_RD) + msgs[0].len = info; + else if (msgs_num == 2 && + msgs[1].flags & I2C_M_RD) + msgs[1].len = info; + } + if (completion_done(&bus->cmd_complete) == false) + complete(&bus->cmd_complete); + break; + + case I2C_NACK_IND: + /* MASTER transmit got a NACK before tx all bytes */ + bus->cmd_err = -ENXIO; + if (bus->master_or_slave == I2C_MASTER) + complete(&bus->cmd_complete); + + break; + case I2C_BUS_ERR_IND: + /* Bus error */ + bus->cmd_err = -EAGAIN; + if (bus->master_or_slave == I2C_MASTER) + complete(&bus->cmd_complete); + + break; + case I2C_WAKE_UP_IND: + /* I2C wake up */ + break; + default: + break; + } + + bus->operation = I2C_NO_OPER; +} + +static u8 npcm_i2c_fifo_usage(struct npcm_i2c *bus) +{ + if (bus->operation == I2C_WRITE_OPER) + return FIELD_GET(NPCM_I2CTXF_STS_TX_BYTES, + ioread8(bus->reg + NPCM_I2CTXF_STS)); + if (bus->operation == I2C_READ_OPER) + return FIELD_GET(NPCM_I2CRXF_STS_RX_BYTES, + ioread8(bus->reg + NPCM_I2CRXF_STS)); + return 0; +} + +static void npcm_i2c_write_to_fifo_master(struct npcm_i2c *bus, u16 max_bytes) +{ + u8 size_free_fifo; + + /* + * Fill the FIFO, while the FIFO is not full and there are more bytes + * to write + */ + size_free_fifo = I2C_HW_FIFO_SIZE - npcm_i2c_fifo_usage(bus); + while (max_bytes-- && size_free_fifo) { + if (bus->wr_ind < bus->wr_size) + npcm_i2c_wr_byte(bus, bus->wr_buf[bus->wr_ind++]); + else + npcm_i2c_wr_byte(bus, 0xFF); + size_free_fifo = I2C_HW_FIFO_SIZE - npcm_i2c_fifo_usage(bus); + } +} + +/* + * npcm_i2c_set_fifo: + * configure the FIFO before using it. If nread is -1 RX FIFO will not be + * configured. same for nwrite + */ +static void npcm_i2c_set_fifo(struct npcm_i2c *bus, int nread, int nwrite) +{ + u8 rxf_ctl = 0; + + if (!bus->fifo_use) + return; + npcm_i2c_select_bank(bus, I2C_BANK_1); + npcm_i2c_clear_tx_fifo(bus); + npcm_i2c_clear_rx_fifo(bus); + + /* configure RX FIFO */ + if (nread > 0) { + rxf_ctl = min_t(int, nread, I2C_HW_FIFO_SIZE); + + /* set LAST bit. if LAST is set next FIFO packet is nacked */ + if (nread <= I2C_HW_FIFO_SIZE) + rxf_ctl |= NPCM_I2CRXF_CTL_LAST_PEC; + + /* + * if we are about to read the first byte in blk rd mode, + * don't NACK it. If slave returns zero size HW can't NACK + * it immidiattly, it will read extra byte and then NACK. + */ + if (bus->rd_ind == 0 && bus->read_block_use) { + /* set fifo to read one byte, no last: */ + rxf_ctl = 1; + } + + /* set fifo size: */ + iowrite8(rxf_ctl, bus->reg + NPCM_I2CRXF_CTL); + } + + /* configure TX FIFO */ + if (nwrite > 0) { + if (nwrite > I2C_HW_FIFO_SIZE) + /* data to send is more then FIFO size. */ + iowrite8(I2C_HW_FIFO_SIZE, bus->reg + NPCM_I2CTXF_CTL); + else + iowrite8(nwrite, bus->reg + NPCM_I2CTXF_CTL); + + npcm_i2c_clear_tx_fifo(bus); + } +} + +static void npcm_i2c_read_fifo(struct npcm_i2c *bus, u8 bytes_in_fifo) +{ + u8 data; + + while (bytes_in_fifo--) { + data = npcm_i2c_rd_byte(bus); + if (bus->rd_ind < bus->rd_size) + bus->rd_buf[bus->rd_ind++] = data; + } +} + +static inline void npcm_i2c_clear_master_status(struct npcm_i2c *bus) +{ + u8 val; + + /* Clear NEGACK, STASTR and BER bits */ + val = NPCM_I2CST_BER | NPCM_I2CST_NEGACK | NPCM_I2CST_STASTR; + iowrite8(val, bus->reg + NPCM_I2CST); +} + +static void npcm_i2c_master_abort(struct npcm_i2c *bus) +{ + /* Only current master is allowed to issue a stop condition */ + if (!npcm_i2c_is_master(bus)) + return; + + npcm_i2c_eob_int(bus, true); + npcm_i2c_master_stop(bus); + npcm_i2c_clear_master_status(bus); +} + +static void npcm_i2c_master_fifo_read(struct npcm_i2c *bus) +{ + int rcount; + int fifo_bytes; + enum i2c_state_ind ind = I2C_MASTER_DONE_IND; + + fifo_bytes = npcm_i2c_fifo_usage(bus); + rcount = bus->rd_size - bus->rd_ind; + + /* + * In order not to change the RX_TRH during transaction (we found that + * this might be problematic if it takes too much time to read the FIFO) + * we read the data in the following way. If the number of bytes to + * read == FIFO Size + C (where C < FIFO Size)then first read C bytes + * and in the next int we read rest of the data. + */ + if (rcount < (2 * I2C_HW_FIFO_SIZE) && rcount > I2C_HW_FIFO_SIZE) + fifo_bytes = rcount - I2C_HW_FIFO_SIZE; + + if (rcount <= fifo_bytes) { + /* last bytes are about to be read - end of tx */ + bus->state = I2C_STOP_PENDING; + bus->stop_ind = ind; + npcm_i2c_eob_int(bus, true); + /* Stop should be set before reading last byte. */ + npcm_i2c_master_stop(bus); + npcm_i2c_read_fifo(bus, fifo_bytes); + } else { + npcm_i2c_read_fifo(bus, fifo_bytes); + rcount = bus->rd_size - bus->rd_ind; + npcm_i2c_set_fifo(bus, rcount, -1); + } +} + +static void npcm_i2c_irq_master_handler_write(struct npcm_i2c *bus) +{ + u16 wcount; + + if (bus->fifo_use) + npcm_i2c_clear_tx_fifo(bus); /* clear the TX fifo status bit */ + + /* Master write operation - last byte handling */ + if (bus->wr_ind == bus->wr_size) { + if (bus->fifo_use && npcm_i2c_fifo_usage(bus) > 0) + /* + * No more bytes to send (to add to the FIFO), + * however the FIFO is not empty yet. It is + * still in the middle of tx. Currently there's nothing + * to do except for waiting to the end of the tx + * We will get an int when the FIFO will get empty. + */ + return; + + if (bus->rd_size == 0) { + /* all bytes have been written, in wr only operation */ + npcm_i2c_eob_int(bus, true); + bus->state = I2C_STOP_PENDING; + bus->stop_ind = I2C_MASTER_DONE_IND; + npcm_i2c_master_stop(bus); + /* Clear SDA Status bit (by writing dummy byte) */ + npcm_i2c_wr_byte(bus, 0xFF); + + } else { + /* last write-byte written on previous int - restart */ + npcm_i2c_set_fifo(bus, bus->rd_size, -1); + /* Generate repeated start upon next write to SDA */ + npcm_i2c_master_start(bus); + + /* + * Receiving one byte only - stall after successful + * completion of send address byte. If we NACK here, and + * slave doesn't ACK the address, we might + * unintentionally NACK the next multi-byte read. + */ + if (bus->rd_size == 1) + npcm_i2c_stall_after_start(bus, true); + + /* Next int will occur on read */ + bus->operation = I2C_READ_OPER; + /* send the slave address in read direction */ + npcm_i2c_wr_byte(bus, bus->dest_addr | 0x1); + } + } else { + /* write next byte not last byte and not slave address */ + if (!bus->fifo_use || bus->wr_size == 1) { + npcm_i2c_wr_byte(bus, bus->wr_buf[bus->wr_ind++]); + } else { + wcount = bus->wr_size - bus->wr_ind; + npcm_i2c_set_fifo(bus, -1, wcount); + if (wcount) + npcm_i2c_write_to_fifo_master(bus, wcount); + } + } +} + +static void npcm_i2c_irq_master_handler_read(struct npcm_i2c *bus) +{ + u16 block_extra_bytes_size; + u8 data; + + /* added bytes to the packet: */ + block_extra_bytes_size = bus->read_block_use + bus->PEC_use; + + /* + * Perform master read, distinguishing between last byte and the rest of + * the bytes. The last byte should be read when the clock is stopped + */ + if (bus->rd_ind == 0) { /* first byte handling: */ + if (bus->read_block_use) { + /* first byte in block protocol is the size: */ + data = npcm_i2c_rd_byte(bus); + data = clamp_val(data, 1, I2C_SMBUS_BLOCK_MAX); + bus->rd_size = data + block_extra_bytes_size; + bus->rd_buf[bus->rd_ind++] = data; + + /* clear RX FIFO interrupt status: */ + if (bus->fifo_use) { + data = ioread8(bus->reg + NPCM_I2CFIF_CTS); + data = data | NPCM_I2CFIF_CTS_RXF_TXE; + iowrite8(data, bus->reg + NPCM_I2CFIF_CTS); + } + + npcm_i2c_set_fifo(bus, bus->rd_size - 1, -1); + npcm_i2c_stall_after_start(bus, false); + } else { + npcm_i2c_clear_tx_fifo(bus); + npcm_i2c_master_fifo_read(bus); + } + } else { + if (bus->rd_size == block_extra_bytes_size && + bus->read_block_use) { + bus->state = I2C_STOP_PENDING; + bus->stop_ind = I2C_BLOCK_BYTES_ERR_IND; + bus->cmd_err = -EIO; + npcm_i2c_eob_int(bus, true); + npcm_i2c_master_stop(bus); + npcm_i2c_read_fifo(bus, npcm_i2c_fifo_usage(bus)); + } else { + npcm_i2c_master_fifo_read(bus); + } + } +} + +static void npcm_i2c_irq_handle_nmatch(struct npcm_i2c *bus) +{ + iowrite8(NPCM_I2CST_NMATCH, bus->reg + NPCM_I2CST); + npcm_i2c_nack(bus); + bus->stop_ind = I2C_BUS_ERR_IND; + npcm_i2c_callback(bus, bus->stop_ind, npcm_i2c_get_index(bus)); +} + +/* A NACK has occurred */ +static void npcm_i2c_irq_handle_nack(struct npcm_i2c *bus) +{ + u8 val; + + if (bus->nack_cnt < ULLONG_MAX) + bus->nack_cnt++; + + if (bus->fifo_use) { + /* + * if there are still untransmitted bytes in TX FIFO + * reduce them from wr_ind + */ + if (bus->operation == I2C_WRITE_OPER) + bus->wr_ind -= npcm_i2c_fifo_usage(bus); + + /* clear the FIFO */ + iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO, bus->reg + NPCM_I2CFIF_CTS); + } + + /* In master write operation, got unexpected NACK */ + bus->stop_ind = I2C_NACK_IND; + /* Only current master is allowed to issue Stop Condition */ + if (npcm_i2c_is_master(bus)) { + /* stopping in the middle */ + npcm_i2c_eob_int(bus, false); + npcm_i2c_master_stop(bus); + + /* + * The bus is released from stall only after the SW clears + * NEGACK bit. Then a Stop condition is sent. + */ + npcm_i2c_clear_master_status(bus); + readx_poll_timeout_atomic(ioread8, bus->reg + NPCM_I2CCST, val, + !(val & NPCM_I2CCST_BUSY), 10, 200); + } + bus->state = I2C_IDLE; + + /* + * In Master mode, NACK should be cleared only after STOP. + * In such case, the bus is released from stall only after the + * software clears NACK bit. Then a Stop condition is sent. + */ + npcm_i2c_callback(bus, bus->stop_ind, bus->wr_ind); +} + + /* Master mode: a Bus Error has been identified */ +static void npcm_i2c_irq_handle_ber(struct npcm_i2c *bus) +{ + if (bus->ber_cnt < ULLONG_MAX) + bus->ber_cnt++; + bus->stop_ind = I2C_BUS_ERR_IND; + if (npcm_i2c_is_master(bus)) { + npcm_i2c_master_abort(bus); + } else { + npcm_i2c_clear_master_status(bus); + + /* Clear BB (BUS BUSY) bit */ + iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST); + + bus->cmd_err = -EAGAIN; + npcm_i2c_callback(bus, bus->stop_ind, npcm_i2c_get_index(bus)); + } + bus->state = I2C_IDLE; +} + + /* EOB: a master End Of Busy (meaning STOP completed) */ +static void npcm_i2c_irq_handle_eob(struct npcm_i2c *bus) +{ + npcm_i2c_eob_int(bus, false); + bus->state = I2C_IDLE; + npcm_i2c_callback(bus, bus->stop_ind, bus->rd_ind); +} + +/* Address sent and requested stall occurred (Master mode) */ +static void npcm_i2c_irq_handle_stall_after_start(struct npcm_i2c *bus) +{ + if (npcm_i2c_is_quick(bus)) { + bus->state = I2C_STOP_PENDING; + bus->stop_ind = I2C_MASTER_DONE_IND; + npcm_i2c_eob_int(bus, true); + npcm_i2c_master_stop(bus); + } else if ((bus->rd_size == 1) && !bus->read_block_use) { + /* + * Receiving one byte only - set NACK after ensuring + * slave ACKed the address byte. + */ + npcm_i2c_nack(bus); + } + + /* Reset stall-after-address-byte */ + npcm_i2c_stall_after_start(bus, false); + + /* Clear stall only after setting STOP */ + iowrite8(NPCM_I2CST_STASTR, bus->reg + NPCM_I2CST); +} + +/* SDA status is set - TX or RX, master */ +static void npcm_i2c_irq_handle_sda(struct npcm_i2c *bus, u8 i2cst) +{ + u8 fif_cts; + + if (!npcm_i2c_is_master(bus)) + return; + + if (bus->state == I2C_IDLE) { + bus->stop_ind = I2C_WAKE_UP_IND; + + if (npcm_i2c_is_quick(bus) || bus->read_block_use) + /* + * Need to stall after successful + * completion of sending address byte + */ + npcm_i2c_stall_after_start(bus, true); + else + npcm_i2c_stall_after_start(bus, false); + + /* + * Receiving one byte only - stall after successful completion + * of sending address byte If we NACK here, and slave doesn't + * ACK the address, we might unintentionally NACK the next + * multi-byte read + */ + if (bus->wr_size == 0 && bus->rd_size == 1) + npcm_i2c_stall_after_start(bus, true); + + /* Initiate I2C master tx */ + + /* select bank 1 for FIFO regs */ + npcm_i2c_select_bank(bus, I2C_BANK_1); + + fif_cts = ioread8(bus->reg + NPCM_I2CFIF_CTS); + fif_cts = fif_cts & ~NPCM_I2CFIF_CTS_SLVRSTR; + + /* clear FIFO and relevant status bits. */ + fif_cts = fif_cts | NPCM_I2CFIF_CTS_CLR_FIFO; + iowrite8(fif_cts, bus->reg + NPCM_I2CFIF_CTS); + + /* re-enable */ + fif_cts = fif_cts | NPCM_I2CFIF_CTS_RXF_TXE; + iowrite8(fif_cts, bus->reg + NPCM_I2CFIF_CTS); + + /* + * Configure the FIFO threshold: + * according to the needed # of bytes to read. + * Note: due to HW limitation can't config the rx fifo before it + * got and ACK on the restart. LAST bit will not be reset unless + * RX completed. It will stay set on the next tx. + */ + if (bus->wr_size) + npcm_i2c_set_fifo(bus, -1, bus->wr_size); + else + npcm_i2c_set_fifo(bus, bus->rd_size, -1); + + bus->state = I2C_OPER_STARTED; + + if (npcm_i2c_is_quick(bus) || bus->wr_size) + npcm_i2c_wr_byte(bus, bus->dest_addr); + else + npcm_i2c_wr_byte(bus, bus->dest_addr | BIT(0)); + /* SDA interrupt, after start\restart */ + } else { + if (NPCM_I2CST_XMIT & i2cst) { + bus->operation = I2C_WRITE_OPER; + npcm_i2c_irq_master_handler_write(bus); + } else { + bus->operation = I2C_READ_OPER; + npcm_i2c_irq_master_handler_read(bus); + } + } +} + +static int npcm_i2c_int_master_handler(struct npcm_i2c *bus) +{ + u8 i2cst; + int ret = -EIO; + + i2cst = ioread8(bus->reg + NPCM_I2CST); + + if (FIELD_GET(NPCM_I2CST_NMATCH, i2cst)) { + npcm_i2c_irq_handle_nmatch(bus); + return 0; + } + /* A NACK has occurred */ + if (FIELD_GET(NPCM_I2CST_NEGACK, i2cst)) { + npcm_i2c_irq_handle_nack(bus); + return 0; + } + + /* Master mode: a Bus Error has been identified */ + if (FIELD_GET(NPCM_I2CST_BER, i2cst)) { + npcm_i2c_irq_handle_ber(bus); + return 0; + } + + /* EOB: a master End Of Busy (meaning STOP completed) */ + if ((FIELD_GET(NPCM_I2CCTL1_EOBINTE, + ioread8(bus->reg + NPCM_I2CCTL1)) == 1) && + (FIELD_GET(NPCM_I2CCST3_EO_BUSY, + ioread8(bus->reg + NPCM_I2CCST3)))) { + npcm_i2c_irq_handle_eob(bus); + return 0; + } + + /* Address sent and requested stall occurred (Master mode) */ + if (FIELD_GET(NPCM_I2CST_STASTR, i2cst)) { + npcm_i2c_irq_handle_stall_after_start(bus); + ret = 0; + } + + /* SDA status is set - TX or RX, master */ + if (FIELD_GET(NPCM_I2CST_SDAST, i2cst) || + (bus->fifo_use && + (npcm_i2c_tx_fifo_empty(bus) || npcm_i2c_rx_fifo_full(bus)))) { + npcm_i2c_irq_handle_sda(bus, i2cst); + ret = 0; + } + + return ret; +} + +/* recovery using TGCLK functionality of the module */ +static int npcm_i2c_recovery_tgclk(struct i2c_adapter *_adap) +{ + u8 val; + u8 fif_cts; + bool done = false; + int status = -ENOTRECOVERABLE; + struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap); + /* Allow 3 bytes (27 toggles) to be read from the slave: */ + int iter = 27; + + if ((npcm_i2c_get_SDA(_adap) == 1) && (npcm_i2c_get_SCL(_adap) == 1)) { + dev_dbg(bus->dev, "bus%d recovery skipped, bus not stuck", + bus->num); + npcm_i2c_reset(bus); + return status; + } + + npcm_i2c_int_enable(bus, false); + npcm_i2c_disable(bus); + npcm_i2c_enable(bus); + iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST); + npcm_i2c_clear_tx_fifo(bus); + npcm_i2c_clear_rx_fifo(bus); + iowrite8(0, bus->reg + NPCM_I2CRXF_CTL); + iowrite8(0, bus->reg + NPCM_I2CTXF_CTL); + npcm_i2c_stall_after_start(bus, false); + + /* select bank 1 for FIFO regs */ + npcm_i2c_select_bank(bus, I2C_BANK_1); + + /* clear FIFO and relevant status bits. */ + fif_cts = ioread8(bus->reg + NPCM_I2CFIF_CTS); + fif_cts &= ~NPCM_I2CFIF_CTS_SLVRSTR; + fif_cts |= NPCM_I2CFIF_CTS_CLR_FIFO; + iowrite8(fif_cts, bus->reg + NPCM_I2CFIF_CTS); + npcm_i2c_set_fifo(bus, -1, 0); + + /* Repeat the following sequence until SDA is released */ + do { + /* Issue a single SCL toggle */ + iowrite8(NPCM_I2CCST_TGSCL, bus->reg + NPCM_I2CCST); + usleep_range(20, 30); + /* If SDA line is inactive (high), stop */ + if (npcm_i2c_get_SDA(_adap)) { + done = true; + status = 0; + } + } while (!done && iter--); + + /* If SDA line is released: send start-addr-stop, to re-sync. */ + if (npcm_i2c_get_SDA(_adap)) { + /* Send an address byte in write direction: */ + npcm_i2c_wr_byte(bus, bus->dest_addr); + npcm_i2c_master_start(bus); + /* Wait until START condition is sent */ + status = readx_poll_timeout(npcm_i2c_get_SCL, _adap, val, !val, + 20, 200); + /* If START condition was sent */ + if (npcm_i2c_is_master(bus) > 0) { + usleep_range(20, 30); |