diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c index cdea7f440a9e..20a2f903b7f6 100644 --- a/drivers/i2c/busses/i2c-npcm7xx.c +++ b/drivers/i2c/busses/i2c-npcm7xx.c @@ -563,6 +563,15 @@ static inline void npcm_i2c_nack(struct npcm_i2c *bus) iowrite8(val, bus->reg + NPCM_I2CCTL1); } +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); +} + #if IS_ENABLED(CONFIG_I2C_SLAVE) static void npcm_i2c_slave_int_enable(struct npcm_i2c *bus, bool enable) { @@ -642,8 +651,8 @@ static void npcm_i2c_reset(struct npcm_i2c *bus) 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 and disable EOB */ + npcm_i2c_eob_int(bus, false); /* Clear all fifo bits: */ iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO, bus->reg + NPCM_I2CFIF_CTS); @@ -655,6 +664,9 @@ static void npcm_i2c_reset(struct npcm_i2c *bus) } #endif + /* clear status bits for spurious interrupts */ + npcm_i2c_clear_master_status(bus); + bus->state = I2C_IDLE; } @@ -815,15 +827,6 @@ static void npcm_i2c_read_fifo(struct npcm_i2c *bus, u8 bytes_in_fifo) } } -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 */ @@ -1231,7 +1234,16 @@ static irqreturn_t npcm_i2c_int_slave_handler(struct npcm_i2c *bus) ret = IRQ_HANDLED; } /* SDAST */ - return ret; + /* + * if irq is not one of the above, make sure EOB is disabled and all + * status bits are cleared. + */ + if (ret == IRQ_NONE) { + npcm_i2c_eob_int(bus, false); + npcm_i2c_clear_master_status(bus); + } + + return IRQ_HANDLED; } static int npcm_i2c_reg_slave(struct i2c_client *client) @@ -1467,6 +1479,9 @@ static void npcm_i2c_irq_handle_nack(struct npcm_i2c *bus) npcm_i2c_eob_int(bus, false); npcm_i2c_master_stop(bus); + /* Clear SDA Status bit (by reading dummy byte) */ + npcm_i2c_rd_byte(bus); + /* * The bus is released from stall only after the SW clears * NEGACK bit. Then a Stop condition is sent. @@ -1474,6 +1489,8 @@ static void npcm_i2c_irq_handle_nack(struct npcm_i2c *bus) npcm_i2c_clear_master_status(bus); readx_poll_timeout_atomic(ioread8, bus->reg + NPCM_I2CCST, val, !(val & NPCM_I2CCST_BUSY), 10, 200); + /* verify no status bits are still set after bus is released */ + npcm_i2c_clear_master_status(bus); } bus->state = I2C_IDLE; @@ -1672,10 +1689,10 @@ static int npcm_i2c_recovery_tgclk(struct i2c_adapter *_adap) 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); + dev_dbg(bus->dev, "bus%d-0x%x recovery skipped, bus not stuck", + bus->num, bus->dest_addr); npcm_i2c_reset(bus); - return status; + return 0; } npcm_i2c_int_enable(bus, false); @@ -1909,6 +1926,7 @@ static int npcm_i2c_init_module(struct npcm_i2c *bus, enum i2c_mode mode, bus_freq_hz < I2C_FREQ_MIN_HZ || bus_freq_hz > I2C_FREQ_MAX_HZ) return -EINVAL; + npcm_i2c_int_enable(bus, false); npcm_i2c_disable(bus); /* Configure FIFO mode : */ @@ -1937,10 +1955,17 @@ static int npcm_i2c_init_module(struct npcm_i2c *bus, enum i2c_mode mode, val = (val | NPCM_I2CCTL1_NMINTE) & ~NPCM_I2CCTL1_RWS; iowrite8(val, bus->reg + NPCM_I2CCTL1); - npcm_i2c_int_enable(bus, true); - npcm_i2c_reset(bus); + /* check HW is OK: SDA and SCL should be high at this point. */ + if ((npcm_i2c_get_SDA(&bus->adap) == 0) || (npcm_i2c_get_SCL(&bus->adap) == 0)) { + dev_err(bus->dev, "I2C%d init fail: lines are low\n", bus->num); + dev_err(bus->dev, "SDA=%d SCL=%d\n", npcm_i2c_get_SDA(&bus->adap), + npcm_i2c_get_SCL(&bus->adap)); + return -ENXIO; + } + + npcm_i2c_int_enable(bus, true); return 0; } @@ -1988,10 +2013,14 @@ static irqreturn_t npcm_i2c_bus_irq(int irq, void *dev_id) #if IS_ENABLED(CONFIG_I2C_SLAVE) if (bus->slave) { bus->master_or_slave = I2C_SLAVE; - return npcm_i2c_int_slave_handler(bus); + if (npcm_i2c_int_slave_handler(bus)) + return IRQ_HANDLED; } #endif - return IRQ_NONE; + /* clear status bits for spurious interrupts */ + npcm_i2c_clear_master_status(bus); + + return IRQ_HANDLED; } static bool npcm_i2c_master_start_xmit(struct npcm_i2c *bus, @@ -2048,7 +2077,6 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, u8 *write_data, *read_data; u8 slave_addr; unsigned long timeout; - int ret = 0; bool read_block = false; bool read_PEC = false; u8 bus_busy; @@ -2138,12 +2166,12 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, bus->read_block_use = read_block; reinit_completion(&bus->cmd_complete); - if (!npcm_i2c_master_start_xmit(bus, slave_addr, nwrite, nread, - write_data, read_data, read_PEC, - read_block)) - ret = -EBUSY; - if (ret != -EBUSY) { + npcm_i2c_int_enable(bus, true); + + if (npcm_i2c_master_start_xmit(bus, slave_addr, nwrite, nread, + write_data, read_data, read_PEC, + read_block)) { time_left = wait_for_completion_timeout(&bus->cmd_complete, timeout); @@ -2157,26 +2185,31 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, } } } - ret = bus->cmd_err; /* if there was BER, check if need to recover the bus: */ if (bus->cmd_err == -EAGAIN) - ret = i2c_recover_bus(adap); + bus->cmd_err = i2c_recover_bus(adap); /* * After any type of error, check if LAST bit is still set, * due to a HW issue. * It cannot be cleared without resetting the module. */ - if (bus->cmd_err && - (NPCM_I2CRXF_CTL_LAST_PEC & ioread8(bus->reg + NPCM_I2CRXF_CTL))) + else if (bus->cmd_err && + (NPCM_I2CRXF_CTL_LAST_PEC & ioread8(bus->reg + NPCM_I2CRXF_CTL))) npcm_i2c_reset(bus); + /* after any xfer, successful or not, stall and EOB must be disabled */ + npcm_i2c_stall_after_start(bus, false); + npcm_i2c_eob_int(bus, false); + #if IS_ENABLED(CONFIG_I2C_SLAVE) /* reenable slave if it was enabled */ if (bus->slave) iowrite8((bus->slave->addr & 0x7F) | NPCM_I2CADDR_SAEN, bus->reg + NPCM_I2CADDR1); +#else + npcm_i2c_int_enable(bus, false); #endif return bus->cmd_err; }