* [PATCH v10 2/3] i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver
2020-05-10 10:23 [PATCH v10 0/3] i2c: npcm7xx: add NPCM i2c controller driver Tali Perry
2020-05-10 10:23 ` [PATCH v10 1/3] dt-bindings: i2c: npcm7xx: add NPCM I2C controller Tali Perry
@ 2020-05-10 10:23 ` Tali Perry
2020-05-11 9:17 ` Andy Shevchenko
2020-05-10 10:23 ` [PATCH v10 3/3] i2c: npcm7xx: Add support for slave mode for Nuvoton Tali Perry
2 siblings, 1 reply; 8+ messages in thread
From: Tali Perry @ 2020-05-10 10:23 UTC (permalink / raw)
To: ofery, brendanhiggins, avifishman70, tmaimon77, kfting, venture,
yuenn, benjaminfair, robh+dt, wsa, andriy.shevchenko
Cc: devicetree, openbmc, linux-kernel, Tali Perry, linux-i2c,
linux-arm-kernel
Add Nuvoton NPCM BMC I2C controller driver.
Signed-off-by: Tali Perry <tali.perry1@gmail.com>
---
drivers/i2c/busses/Kconfig | 9 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-npcm7xx.c | 1853 ++++++++++++++++++++++++++++++
3 files changed, 1863 insertions(+)
create mode 100644 drivers/i2c/busses/i2c-npcm7xx.c
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 2ddca08f8a76..a2cfc555c284 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -791,6 +791,15 @@ 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 25d60889713c..8f3dfd376bec 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -81,6 +81,7 @@ 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..e732c40f0cf3
--- /dev/null
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -0,0 +1,1853 @@
+// 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>
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+#include <linux/debugfs.h>
+#endif
+#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>
+
+//#define _I2C_DEBUG_
+
+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 held)
+// 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
+
+// BANK 0 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
+
+// supported clk settings. values in KHz.
+#define I2C_FREQ_MIN 10
+#define I2C_FREQ_MAX 1000
+
+// SCLFRQ field position
+#define SCLFRQ_0_TO_6 GENMASK(6, 0)
+#define SCLFRQ_7_TO_8 GENMASK(8, 7)
+
+#define I2C_NUM_OF_ADDR 10
+
+// 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 irq;
+ 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;
+ u8 int_cnt;
+ u32 clk_period_us;
+ unsigned long int_time_stamp;
+ unsigned long bus_freq; // in kHz
+ u32 xmits;
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+ struct dentry *debugfs;/* debugfs device directory */
+ uint64_t ber_count;
+ uint64_t rec_succ_count;
+ uint64_t rec_fail_count;
+ uint64_t nack_count;
+ uint64_t timeout_count;
+#endif
+};
+
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+static struct dentry *npcm_i2c_debugfs_dir; /* i2c debugfs directory */
+static const char *ber_cnt_name = "ber_count";
+static const char *rec_succ_cnt_name = "rec_succ_count";
+static const char *rec_fail_cnt_name = "rec_fail_count";
+static const char *nack_cnt_name = "nack_count";
+static const char *timeout_cnt_name = "timeout_count";
+#endif
+
+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->int_cnt = 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) interrupt
+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);
+ 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;
+ u8 i2cctl2;
+
+ i2cctl1 = ioread8(bus->reg + NPCM_I2CCTL1);
+ i2cctl2 = ioread8(bus->reg + NPCM_I2CCTL2);
+
+ 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 transaction 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
+ // info: number of transmitted 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 u32 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_to_send)
+{
+ // Fill the FIFO, while the FIFO is not full and there are more bytes to
+ // write
+ while ((max_bytes_to_send--) &&
+ (I2C_HW_FIFO_SIZE - npcm_i2c_fifo_usage(bus))) {
+ 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);
+ }
+}
+
+/*
+ * 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 enxt FIFO packet is nacked
+ // regular read of less then buffer size:
+ 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. BTW, if slave return 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.
+ // Configure the FIFO int to be after of FIFO is cleared
+ 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_from_fifo(struct npcm_i2c *bus, u8 bytes_in_fifo)
+{
+ u8 data;
+
+ while (bytes_in_fifo--) {
+ data = npcm_i2c_rd_byte(bus);
+
+ if (bus->master_or_slave == I2C_MASTER) {
+ 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)) {
+ 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 transaction.
+ // Stop should be set before reading last byte.
+ bus->state = I2C_STOP_PENDING;
+ bus->stop_ind = ind;
+ npcm_i2c_eob_int(bus, true);
+ npcm_i2c_master_stop(bus);
+ npcm_i2c_read_from_fifo(bus, fifo_bytes);
+ } else {
+ npcm_i2c_read_from_fifo(bus, fifo_bytes);
+ rcount = bus->rd_size - bus->rd_ind;
+ npcm_i2c_set_fifo(bus, rcount, -1);
+ }
+}
+
+static void npcm_i2c_int_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 a pure wr 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 - need to
+ // restart & send slave address
+ npcm_i2c_set_fifo(bus, bus->rd_size, -1);
+ // Generate repeated start upon next write to SDA
+ npcm_i2c_master_start(bus);
+ if (bus->rd_size == 1)
+ // 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
+ 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_int_master_handler_read(struct npcm_i2c *bus)
+{
+ u16 block_extra_bytes_size;
+ u8 data;
+
+ // Master read operation (pure read or following a write operation).
+
+ // 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:
+ // in block protocol first byte is the size
+ 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_from_fifo(bus, npcm_i2c_fifo_usage(bus));
+ } else {
+ npcm_i2c_master_fifo_read(bus);
+ }
+ }
+}
+
+static irqreturn_t npcm_i2c_int_master_handler(struct npcm_i2c *bus)
+{
+ irqreturn_t ret = IRQ_NONE;
+ u8 fif_cts;
+ u8 val;
+ u8 i2cst = ioread8(bus->reg + NPCM_I2CST);
+
+ if (FIELD_GET(NPCM_I2CST_NMATCH, i2cst)) {
+ 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));
+
+ return IRQ_HANDLED;
+ }
+ // A NACK has occurred
+ if (FIELD_GET(NPCM_I2CST_NEGACK, i2cst)) {
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+ if (bus->nack_count == ULLONG_MAX) {
+ dev_dbg(bus->dev, "%s reaches maximum, reset to 0",
+ nack_cnt_name);
+ bus->nack_count = 0;
+ }
+ bus->nack_count++;
+#endif
+ 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, NACK is a problem
+ // number of bytes sent to master less than required
+ 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, not waiting for ints anymore
+ npcm_i2c_eob_int(bus, false);
+
+ npcm_i2c_master_stop(bus);
+
+ // The bus is released from stall only
+ // after the software 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
+ // generating 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);
+ return IRQ_HANDLED;
+ }
+
+ // Master mode: a Bus Error has been identified
+ if (FIELD_GET(NPCM_I2CST_BER, i2cst)) {
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+ if (bus->ber_count == ULLONG_MAX) {
+ dev_dbg(bus->dev, "%s reach max, reset", ber_cnt_name);
+ bus->ber_count = 0;
+ }
+ bus->ber_count++;
+#endif
+ // Check whether bus arbitration or Start or Stop during data
+ // xfer bus arbitration problem should not result in recovery
+ 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;
+ return IRQ_HANDLED;
+ }
+
+ // A Master End of Busy (meaning Stop Condition happened)
+ // End of Busy int is on and End of Busy is set
+ 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_eob_int(bus, false);
+ bus->state = I2C_IDLE;
+ npcm_i2c_callback(bus, bus->stop_ind, bus->rd_ind);
+ return IRQ_HANDLED;
+ }
+
+ // Address sent and requested stall occurred (Master mode)
+ if (FIELD_GET(NPCM_I2CST_STASTR, i2cst)) {
+ 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);
+
+ ret = IRQ_HANDLED;
+ }
+
+ // 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)))) {
+ // Status Bit is cleared by writing to or reading from SDA
+ // (depending on current direction)
+
+ // Send address:
+ if (bus->state == I2C_IDLE) {
+ if (npcm_i2c_is_master(bus)) {
+ bus->stop_ind = I2C_WAKE_UP_IND;
+
+ // test stall on start
+ 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 transaction
+ // Generate a Start condition on the I2C
+
+ // 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);
+
+ // and enable it
+ 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
+ // 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 |
+ 0x01);
+ }
+
+ return IRQ_HANDLED;
+ // SDA status is set - transmit or receive: Handle master mode
+ } else {
+ if (!(NPCM_I2CST_XMIT & i2cst)) {
+ bus->operation = I2C_READ_OPER;
+ npcm_i2c_int_master_handler_read(bus);
+ } else {
+ bus->operation = I2C_WRITE_OPER;
+ npcm_i2c_int_master_handler_write(bus);
+ }
+ }
+ ret = IRQ_HANDLED;
+ }
+
+ 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;
+ }
+
+ // Disable int
+ 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);
+ udelay(20);
+ // 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) {
+
+ udelay(20);
+ npcm_i2c_master_stop(bus);
+ udelay(200);
+ }
+ }
+ npcm_i2c_reset(bus);
+ npcm_i2c_int_enable(bus, true);
+
+ if ((npcm_i2c_get_SDA(_adap) == 1) && (npcm_i2c_get_SCL(_adap) == 1))
+ status = 0;
+ else
+ status = -ENOTRECOVERABLE;
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+ if (!status) {
+ if (bus->rec_succ_count == ULLONG_MAX) {
+ dev_dbg(bus->dev,
+ "%s reaches maximum, reset to 0",
+ rec_succ_cnt_name);
+ bus->rec_succ_count = 0;
+ }
+ bus->rec_succ_count++;
+ } else {
+ if (bus->rec_succ_count == ULLONG_MAX) {
+ dev_dbg(bus->dev,
+ "%s reaches maximum, reset to 0",
+ rec_succ_cnt_name);
+ bus->rec_fail_count = 0;
+ }
+ bus->rec_fail_count++;
+ }
+#endif
+ return status;
+}
+
+// recovery using bit banging functionality of the module
+static int npcm_i2c_recovery_init(struct i2c_adapter *_adap)
+{
+ struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
+ struct i2c_bus_recovery_info *rinfo = &bus->rinfo;
+
+ rinfo->recover_bus = npcm_i2c_recovery_tgclk;
+ rinfo->prepare_recovery = NULL;
+ rinfo->unprepare_recovery = NULL;
+ rinfo->set_scl = NULL;
+ rinfo->set_sda = NULL;
+
+ dev_dbg(bus->dev, "init i2c recovery using TGCLK\n");
+
+ rinfo->get_scl = npcm_i2c_get_SCL;
+ rinfo->get_sda = npcm_i2c_get_SDA;
+
+ _adap->bus_recovery_info = rinfo;
+
+ return 0;
+}
+
+// SCLFRQ min/max field values
+#define SCLFRQ_MIN 10
+#define SCLFRQ_MAX 511
+
+/*
+ * npcm_i2c_init_clk: init HW timing parameters.
+ * NPCM7XX i2c module timing parameters are depenent on module core clk (APB)
+ * and bus frequency.
+ * 100kHz bus requires tSCL = 4 * SCLFRQ * tCLK. LT and HT are simetric.
+ * 400kHz bus requires assymetric HT and LT. A different equation is recomended
+ * by the HW designer, given core clock range (equations in comments below).
+ *
+ */
+static int npcm_i2c_init_clk(struct npcm_i2c *bus, u32 bus_freq)
+{
+ u32 k1 = 0;
+ u32 k2 = 0;
+ u8 dbnct = 0;
+ u32 sclfrq = 0;
+ u8 hldt = 7;
+ bool fast_mode = false;
+ u32 src_clk_freq; // in KHz
+
+ src_clk_freq = bus->apb_clk / 1000;
+ bus->bus_freq = bus_freq;
+
+ // 100KHz and below:
+ if (bus_freq <= (I2C_MAX_STANDARD_MODE_FREQ / 1000)) {
+ sclfrq = src_clk_freq / (bus_freq * 4);
+
+ if (sclfrq < SCLFRQ_MIN || sclfrq > SCLFRQ_MAX)
+ return -EDOM;
+
+ if (src_clk_freq >= 40000)
+ hldt = 17;
+ else if (src_clk_freq >= 12500)
+ hldt = 15;
+ else
+ hldt = 7;
+ }
+
+ // 400KHz:
+ else if (bus_freq <= (I2C_MAX_FAST_MODE_FREQ / 1000)) {
+ sclfrq = 0;
+ fast_mode = true;
+
+ if (src_clk_freq < 7500)
+ // 400KHZ cannot be supported for core clock < 7.5 MHZ
+ return -EDOM;
+
+ else if (src_clk_freq >= 50000) {
+ k1 = 80;
+ k2 = 48;
+ hldt = 12;
+ dbnct = 7;
+ }
+
+ // Master or Slave with frequency > 25 MHZ
+ else if (src_clk_freq > 25000) {
+ hldt = (DIV_ROUND_UP(src_clk_freq * 300,
+ 1000000) + 7) & 0xFF;
+
+ k1 = DIV_ROUND_UP(src_clk_freq * 1600,
+ 1000000);
+ k2 = DIV_ROUND_UP(src_clk_freq * 900,
+ 1000000);
+ k1 = round_up(k1, 2);
+ k2 = round_up(k2 + 1, 2);
+ if (k1 < SCLFRQ_MIN || k1 > SCLFRQ_MAX ||
+ k2 < SCLFRQ_MIN || k2 > SCLFRQ_MAX)
+ return -EDOM;
+ }
+ }
+
+ else if (bus_freq <= (I2C_MAX_FAST_MODE_PLUS_FREQ / 1000)) {
+ sclfrq = 0;
+ fast_mode = true;
+
+ if (src_clk_freq < 24000)
+ // 1MHZ cannot be supported for master core clock < 15 MHZ
+ // or slave core clock < 24 MHZ
+ return -EDOM;
+
+ k1 = round_up((DIV_ROUND_UP(src_clk_freq * 620,
+ 1000000)), 2);
+ k2 = round_up((DIV_ROUND_UP(src_clk_freq * 380,
+ 1000000) + 1), 2);
+ if (k1 < SCLFRQ_MIN || k1 > SCLFRQ_MAX ||
+ k2 < SCLFRQ_MIN || k2 > SCLFRQ_MAX)
+ return -EDOM;
+
+ // Core clk > 40 MHZ
+ if (src_clk_freq > 40000) {
+ // Set HLDT:
+ // SDA hold time: (HLDT-7) * T(CLK) >= 120
+ // HLDT = 120/T(CLK) + 7 = 120 * FREQ(CLK) + 7
+ hldt = (DIV_ROUND_UP(src_clk_freq * 120,
+ 1000000) + 7) & 0xFF;
+ } else {
+ hldt = 7;
+ dbnct = 2;
+ }
+ }
+
+ // Frequency larger than 1 MHZ is not supported
+ else
+ return false;
+
+ // After clock parameters calculation update reg (ENABLE should be 0):
+ iowrite8(FIELD_PREP(I2CCTL2_SCLFRQ6_0, sclfrq & 0x7F),
+ bus->reg + NPCM_I2CCTL2);
+
+ // force to bank 0, set SCL and fast mode
+ iowrite8(FIELD_PREP(I2CCTL3_400K_MODE, fast_mode) |
+ FIELD_PREP(I2CCTL3_SCLFRQ8_7, (sclfrq >> 7) & 0x3),
+ bus->reg + NPCM_I2CCTL3);
+
+ // Select Bank 0 to access NPCM_I2CCTL4/NPCM_I2CCTL5
+ npcm_i2c_select_bank(bus, I2C_BANK_0);
+
+ if (bus_freq >= (I2C_MAX_FAST_MODE_FREQ / 1000)) {
+ // Set SCL Low/High Time:
+ // k1 = 2 * SCLLT7-0 -> Low Time = k1 / 2
+ // k2 = 2 * SCLLT7-0 -> High Time = k2 / 2
+ iowrite8((u8)k1 / 2, bus->reg + NPCM_I2CSCLLT);
+ iowrite8((u8)k2 / 2, bus->reg + NPCM_I2CSCLHT);
+
+ iowrite8(dbnct, bus->reg + NPCM_I2CCTL5);
+ }
+
+ iowrite8(hldt, bus->reg + NPCM_I2CCTL4);
+
+ // Return to Bank 1, and stay there by default:
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+
+ return true;
+}
+
+static bool npcm_i2c_init_module(struct npcm_i2c *bus, enum i2c_mode mode,
+ u32 bus_freq)
+{
+ u8 val;
+
+ // Check whether module already enabled or frequency is out of bounds
+ if ((bus->state != I2C_DISABLE && bus->state != I2C_IDLE) ||
+ bus_freq < I2C_FREQ_MIN || bus_freq > I2C_FREQ_MAX)
+ return false;
+
+ npcm_i2c_disable(bus);
+
+ // Configure FIFO mode :
+ if (FIELD_GET(I2C_VER_FIFO_EN, ioread8(bus->reg + I2C_VER))) {
+ bus->fifo_use = true;
+ npcm_i2c_select_bank(bus, I2C_BANK_0);
+ val = ioread8(bus->reg + NPCM_I2CFIF_CTL);
+ val |= NPCM_I2CFIF_CTL_FIFO_EN;
+ iowrite8(val, bus->reg + NPCM_I2CFIF_CTL);
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+ } else {
+ bus->fifo_use = false;
+ }
+
+ // Configure I2C module clock frequency
+ if (!npcm_i2c_init_clk(bus, bus_freq)) {
+ dev_err(bus->dev, "npcm_i2c_init_clk failed\n");
+ return false;
+ }
+
+ // Enable module (before configuring CTL1)
+ npcm_i2c_enable(bus);
+ bus->state = I2C_IDLE;
+ val = ioread8(bus->reg + NPCM_I2CCTL1);
+ val = (val | NPCM_I2CCTL1_NMINTE) & ~NPCM_I2CCTL1_RWS;
+ iowrite8(val, bus->reg + NPCM_I2CCTL1);
+
+ npcm_i2c_int_enable(bus, true);
+
+ npcm_i2c_reset(bus);
+
+ return true;
+}
+
+static int __npcm_i2c_init(struct npcm_i2c *bus, struct platform_device *pdev)
+{
+ u32 clk_freq;
+ int ret;
+
+ // Initialize the internal data structures
+ bus->state = I2C_DISABLE;
+ bus->master_or_slave = I2C_SLAVE;
+ bus->int_time_stamp = 0;
+ bus->xmits = 0;
+
+ ret = device_property_read_u32(&pdev->dev, "bus-frequency", &clk_freq);
+ if (ret < 0) {
+ dev_info(&pdev->dev, "Could not read bus-frequency property\n");
+ clk_freq = 100000;
+ }
+
+ ret = npcm_i2c_init_module(bus, I2C_MASTER, clk_freq / 1000);
+ if (!ret) {
+ dev_err(&pdev->dev, "npcm_i2c_init_module failed\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static irqreturn_t npcm_i2c_bus_irq(int irq, void *dev_id)
+{
+ irqreturn_t ret;
+ struct npcm_i2c *bus = dev_id;
+
+ bus->int_cnt++;
+
+ if (npcm_i2c_is_master(bus))
+ bus->master_or_slave = I2C_MASTER;
+
+ if (bus->master_or_slave == I2C_MASTER) {
+ bus->int_time_stamp = jiffies;
+ ret = npcm_i2c_int_master_handler(bus);
+ if (ret == IRQ_HANDLED)
+ return ret;
+ }
+ return IRQ_HANDLED;
+}
+
+static bool npcm_i2c_master_start_xmit(struct npcm_i2c *bus,
+ u8 slave_addr, u16 nwrite, u16 nread,
+ u8 *write_data, u8 *read_data,
+ bool use_PEC, bool use_read_block)
+{
+ if (bus->state != I2C_IDLE) {
+ bus->cmd_err = -EBUSY;
+ return false;
+ }
+ bus->xmits++;
+ bus->dest_addr = (slave_addr << 1) & 0xFE;
+ bus->wr_buf = write_data;
+ bus->wr_size = nwrite;
+ bus->wr_ind = 0;
+ bus->rd_buf = read_data;
+ bus->rd_size = nread;
+ bus->rd_ind = 0;
+ bus->PEC_use = 0;
+
+ // for write, PEC is appended to buffer from i2c IF. PEC flag is ignored
+ if (nread)
+ bus->PEC_use = use_PEC;
+ bus->read_block_use = use_read_block;
+ if (nread && !nwrite)
+ bus->operation = I2C_READ_OPER;
+ else
+ bus->operation = I2C_WRITE_OPER;
+ bus->int_cnt = 0;
+ if (bus->fifo_use) {
+ u8 i2cfif_cts;
+
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+ // clear FIFO and relevant status bits.
+ i2cfif_cts = ioread8(bus->reg + NPCM_I2CFIF_CTS);
+ i2cfif_cts &= ~NPCM_I2CFIF_CTS_SLVRSTR;
+ i2cfif_cts |= NPCM_I2CFIF_CTS_CLR_FIFO;
+ iowrite8(i2cfif_cts, bus->reg + NPCM_I2CFIF_CTS);
+ }
+
+ bus->state = I2C_IDLE;
+
+ npcm_i2c_stall_after_start(bus, true);
+ npcm_i2c_master_start(bus);
+
+ return true;
+}
+
+static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+ int num)
+{
+ struct npcm_i2c *bus = container_of(adap, struct npcm_i2c, adap);
+ struct i2c_msg *msg0, *msg1;
+ unsigned long time_left, flags;
+ u16 nwrite, nread;
+ u8 *write_data, *read_data;
+ u8 slave_addr;
+ int timeout;
+ int ret = 0;
+ bool read_block = false;
+ bool read_PEC = false;
+ u8 bus_busy;
+ unsigned long timeout_usec;
+
+ if (bus->state == I2C_DISABLE) {
+ dev_err(bus->dev, "I2C%d module is disabled", bus->num);
+ return -EINVAL;
+ }
+
+ if (num > 2 || num < 1) {
+ dev_err(bus->dev, "I2C cmd not supported num of msgs=%d", num);
+ return -EINVAL;
+ }
+
+ msg0 = &msgs[0];
+ slave_addr = msg0->addr;
+ if (msg0->flags & I2C_M_RD) { // read
+ if (num == 2) {
+ dev_err(bus->dev, "num=2 but 1st msg rd instead of wr");
+ return -EINVAL;
+ }
+ nwrite = 0;
+ write_data = NULL;
+ read_data = msg0->buf;
+ if (msg0->flags & I2C_M_RECV_LEN) {
+ nread = 1;
+ read_block = true;
+ if (msg0->flags & I2C_CLIENT_PEC)
+ read_PEC = true;
+ } else {
+ nread = msg0->len;
+ }
+ } else { // write
+ nwrite = msg0->len;
+ write_data = msg0->buf;
+ nread = 0;
+ read_data = NULL;
+ if (num == 2) {
+ msg1 = &msgs[1];
+ read_data = msg1->buf;
+ if (slave_addr != msg1->addr) {
+ dev_err(bus->dev,
+ "SA==%02x but msg1->addr==%02x\n",
+ slave_addr, msg1->addr);
+ return -EINVAL;
+ }
+ if ((msg1->flags & I2C_M_RD) == 0) {
+ dev_err(bus->dev,
+ "num = 2 but both msg are write.\n");
+ return -EINVAL;
+ }
+ if (msg1->flags & I2C_M_RECV_LEN) {
+ nread = 1;
+ read_block = true;
+ if (msg1->flags & I2C_CLIENT_PEC)
+ read_PEC = true;
+ } else {
+ nread = msg1->len;
+ read_block = false;
+ }
+ }
+ }
+
+ /* Adaptive TimeOut: astimated time in usec + 100% margin */
+ timeout_usec = (2 * 10000 / bus->bus_freq) * (2 + nread + nwrite);
+ timeout = max(msecs_to_jiffies(35), usecs_to_jiffies(timeout_usec));
+ if (nwrite >= 32 * 1024 || nread >= 32 * 1024) {
+ dev_err(bus->dev, "i2c%d buffer too big\n", bus->num);
+ return -EINVAL;
+ }
+
+ time_left = jiffies +
+ msecs_to_jiffies(DEFAULT_STALL_COUNT) + 1;
+ do {
+ /* we must clear slave address immediately when the bus is not
+ * busy, so we spinlock it, but we don't keep the lock for the
+ * entire while since it is too long.
+ */
+ spin_lock_irqsave(&bus->lock, flags);
+ bus_busy = ioread8(bus->reg + NPCM_I2CCST) & NPCM_I2CCST_BB;
+ spin_unlock_irqrestore(&bus->lock, flags);
+
+ } while (time_is_after_jiffies(time_left) && bus_busy);
+
+ if (bus_busy) {
+ iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
+ npcm_i2c_reset(bus);
+ i2c_recover_bus(adap);
+ return -EAGAIN;
+ }
+
+ npcm_i2c_init_params(bus);
+ bus->dest_addr = slave_addr;
+ bus->msgs = msgs;
+ bus->msgs_num = num;
+ bus->cmd_err = 0;
+ 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) {
+ time_left = wait_for_completion_timeout(&bus->cmd_complete,
+ timeout);
+
+ if (time_left == 0) {
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+ if (bus->timeout_count == ULLONG_MAX) {
+ dev_dbg(bus->dev,
+ "%s reaches to maximum, reset to 0",
+ timeout_cnt_name);
+ bus->timeout_count = 0;
+ }
+ bus->timeout_count++;
+#endif
+ if (bus->master_or_slave == I2C_MASTER) {
+ i2c_recover_bus(adap);
+ bus->cmd_err = -EIO;
+ bus->state = I2C_IDLE;
+ }
+ }
+ }
+ 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);
+
+ return bus->cmd_err;
+}
+
+static u32 npcm_i2c_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C |
+ I2C_FUNC_SMBUS_EMUL |
+ I2C_FUNC_SMBUS_BLOCK_DATA |
+ I2C_FUNC_SMBUS_PEC |
+ I2C_FUNC_SLAVE;
+}
+
+static const struct i2c_adapter_quirks npcm_i2c_quirks = {
+ .max_read_len = 32768,
+ .max_write_len = 32768,
+ .max_num_msgs = 2,
+ .flags = I2C_AQ_COMB_WRITE_THEN_READ,
+};
+
+static const struct i2c_algorithm npcm_i2c_algo = {
+ .master_xfer = npcm_i2c_master_xfer,
+ .functionality = npcm_i2c_functionality,
+};
+
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+static int i2c_debugfs_get(void *data, u64 *val)
+{
+ *val = *(u64 *)(data);
+ return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(i2c_debugfs_ops, i2c_debugfs_get, NULL, "0x%02llx\n");
+
+static int i2c_init_debugfs(struct platform_device *pdev, struct npcm_i2c *bus)
+{
+ if (!npcm_i2c_debugfs_dir)
+ return -ENODEV;
+
+ if (!pdev || !bus)
+ return -ENODEV;
+
+ bus->debugfs = debugfs_create_dir(dev_name(&pdev->dev),
+ npcm_i2c_debugfs_dir);
+
+ if (IS_ERR_OR_NULL(bus->debugfs)) {
+ bus->debugfs = NULL;
+ return -ENODEV;
+ }
+
+ debugfs_create_file(ber_cnt_name, 0444, bus->debugfs,
+ &bus->ber_count,
+ &i2c_debugfs_ops);
+
+ debugfs_create_file(rec_succ_cnt_name, 0444, bus->debugfs,
+ &bus->rec_succ_count,
+ &i2c_debugfs_ops);
+
+ debugfs_create_file(rec_fail_cnt_name, 0444, bus->debugfs,
+ &bus->rec_fail_count,
+ &i2c_debugfs_ops);
+
+ debugfs_create_file(nack_cnt_name, 0444, bus->debugfs,
+ &bus->nack_count,
+ &i2c_debugfs_ops);
+
+ debugfs_create_file(timeout_cnt_name, 0444, bus->debugfs,
+ &bus->timeout_count,
+ &i2c_debugfs_ops);
+
+ return 0;
+}
+#endif
+
+static int npcm_i2c_probe_bus(struct platform_device *pdev)
+{
+ struct npcm_i2c *bus;
+ struct i2c_adapter *adap;
+ struct clk *i2c_clk;
+ static struct regmap *gcr_regmap;
+ static struct regmap *clk_regmap;
+ int ret;
+ int num;
+
+ bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
+ if (!bus)
+ return -ENOMEM;
+
+ bus->dev = &pdev->dev;
+
+ num = of_alias_get_id(pdev->dev.of_node, "i2c");
+ bus->num = num;
+ // core clk must be acquired to calculate module timing settings
+ i2c_clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(i2c_clk))
+ return PTR_ERR(i2c_clk);
+ bus->apb_clk = clk_get_rate(i2c_clk);
+
+ gcr_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-gcr");
+ if (IS_ERR(gcr_regmap))
+ return IS_ERR(gcr_regmap);
+ regmap_write(gcr_regmap, NPCM_I2CSEGCTL, NPCM_I2CSEGCTL_INIT_VAL);
+
+ clk_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-clk");
+ if (IS_ERR(clk_regmap))
+ return IS_ERR(clk_regmap);
+
+ bus->reg = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(bus->reg))
+ return PTR_ERR((bus)->reg);
+
+ spin_lock_init(&bus->lock);
+ init_completion(&bus->cmd_complete);
+
+ adap = &bus->adap;
+ adap->owner = THIS_MODULE;
+ adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD | I2C_CLIENT_SLAVE;
+ adap->retries = 3;
+ adap->timeout = HZ;
+ adap->algo = &npcm_i2c_algo;
+ adap->quirks = &npcm_i2c_quirks;
+ adap->algo_data = bus;
+ adap->dev.parent = &pdev->dev;
+ adap->dev.of_node = pdev->dev.of_node;
+ adap->nr = pdev->id;
+
+ bus->irq = platform_get_irq(pdev, 0);
+ if (bus->irq < 0) {
+ dev_err(&pdev->dev, "failed to get IRQ number\n");
+ return bus->irq;
+ }
+
+ ret = devm_request_irq(&pdev->dev, bus->irq, npcm_i2c_bus_irq, 0,
+ dev_name(&pdev->dev), bus);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to request irq %d\n", ret);
+ return ret;
+ }
+
+ ret = __npcm_i2c_init(bus, pdev);
+ if (ret < 0)
+ return ret;
+
+ ret = npcm_i2c_recovery_init(adap);
+ if (ret)
+ return ret;
+
+ i2c_set_adapdata(adap, bus);
+
+ snprintf(bus->adap.name, sizeof(bus->adap.name), "Nuvoton i2c");
+ ret = i2c_add_numbered_adapter(&bus->adap);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to add numbered adapter %d\n", ret);
+ return ret;
+ }
+ platform_set_drvdata(pdev, bus);
+
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+ ret = i2c_init_debugfs(pdev, bus);
+ if (ret < 0)
+ return ret;
+#endif
+ return 0;
+}
+
+static int npcm_i2c_remove_bus(struct platform_device *pdev)
+{
+ unsigned long lock_flags;
+ struct npcm_i2c *bus = platform_get_drvdata(pdev);
+
+ spin_lock_irqsave(&bus->lock, lock_flags);
+ npcm_i2c_disable(bus);
+ spin_unlock_irqrestore(&bus->lock, lock_flags);
+ i2c_del_adapter(&bus->adap);
+
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+ if (!!bus->debugfs) {
+ debugfs_remove_recursive(bus->debugfs);
+ bus->debugfs = NULL;
+ }
+#endif
+
+ return 0;
+}
+
+static const struct of_device_id npcm_i2c_bus_of_table[] = {
+ { .compatible = "nuvoton,npcm750-i2c", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, npcm_i2c_bus_of_table);
+
+static struct platform_driver npcm_i2c_bus_driver = {
+ .probe = npcm_i2c_probe_bus,
+ .remove = npcm_i2c_remove_bus,
+ .driver = {
+ .name = "nuvoton-i2c",
+ .of_match_table = npcm_i2c_bus_of_table,
+ }
+};
+module_platform_driver(npcm_i2c_bus_driver);
+
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+static int __init npcm_i2c_init(void)
+{
+ npcm_i2c_debugfs_dir = debugfs_create_dir("i2c", NULL);
+ if (IS_ERR_OR_NULL(npcm_i2c_debugfs_dir)) {
+ pr_warn("i2c init of debugfs failed\n");
+ npcm_i2c_debugfs_dir = NULL;
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static void __exit npcm_i2c_exit(void)
+{
+ if (!!npcm_i2c_debugfs_dir) {
+ debugfs_remove_recursive(npcm_i2c_debugfs_dir);
+ npcm_i2c_debugfs_dir = NULL;
+ }
+}
+
+module_init(npcm_i2c_init);
+module_exit(npcm_i2c_exit);
+#endif
+
+MODULE_AUTHOR("Avi Fishman <avi.fishman@gmail.com>");
+MODULE_AUTHOR("Tali Perry <tali.perry@nuvoton.com>");
+MODULE_AUTHOR("Tyrone Ting <kfting@nuvoton.com>");
+MODULE_DESCRIPTION("Nuvoton I2C Bus Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION("0.1.2");
+
--
2.22.0
_______________________________________________
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^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH v10 3/3] i2c: npcm7xx: Add support for slave mode for Nuvoton
2020-05-10 10:23 [PATCH v10 0/3] i2c: npcm7xx: add NPCM i2c controller driver Tali Perry
2020-05-10 10:23 ` [PATCH v10 1/3] dt-bindings: i2c: npcm7xx: add NPCM I2C controller Tali Perry
2020-05-10 10:23 ` [PATCH v10 2/3] i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver Tali Perry
@ 2020-05-10 10:23 ` Tali Perry
2 siblings, 0 replies; 8+ messages in thread
From: Tali Perry @ 2020-05-10 10:23 UTC (permalink / raw)
To: ofery, brendanhiggins, avifishman70, tmaimon77, kfting, venture,
yuenn, benjaminfair, robh+dt, wsa, andriy.shevchenko
Cc: devicetree, openbmc, linux-kernel, Tali Perry, linux-i2c,
linux-arm-kernel
Add support for slave mode for Nuvoton
NPCM BMC I2C controller driver.
Signed-off-by: Tali Perry <tali.perry1@gmail.com>
---
drivers/i2c/busses/i2c-npcm7xx.c | 614 +++++++++++++++++++++++++++++++
1 file changed, 614 insertions(+)
diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
index e732c40f0cf3..54af253249d5 100644
--- a/drivers/i2c/busses/i2c-npcm7xx.c
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -73,6 +73,24 @@ enum i2c_state {
I2C_STOP_PENDING,
};
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+// Module supports setting multiple own slave addresses
+enum i2c_addr {
+ I2C_SLAVE_ADDR1 = 0,
+ I2C_SLAVE_ADDR2,
+ I2C_SLAVE_ADDR3,
+ I2C_SLAVE_ADDR4,
+ I2C_SLAVE_ADDR5,
+ I2C_SLAVE_ADDR6,
+ I2C_SLAVE_ADDR7,
+ I2C_SLAVE_ADDR8,
+ I2C_SLAVE_ADDR9,
+ I2C_SLAVE_ADDR10,
+ I2C_GC_ADDR,
+ I2C_ARP_ADDR,
+};
+#endif
+
// init register and default value required to enable module
#define NPCM_I2CSEGCTL 0xE4
#define NPCM_I2CSEGCTL_INIT_VAL 0x0333F000
@@ -100,6 +118,14 @@ enum i2c_state {
#define NPCM_I2CADDR6 0x16
#define NPCM_I2CADDR10 0x17
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+// I2CADDR array: because the addr regs are sprinkled all over the address space
+const int npcm_i2caddr[10] = {NPCM_I2CADDR1, NPCM_I2CADDR2, NPCM_I2CADDR3,
+ NPCM_I2CADDR4, NPCM_I2CADDR5, NPCM_I2CADDR6,
+ NPCM_I2CADDR7, NPCM_I2CADDR8, NPCM_I2CADDR9,
+ NPCM_I2CADDR10};
+#endif
+
#define NPCM_I2CCTL4 0x1A
#define NPCM_I2CCTL5 0x1B
#define NPCM_I2CSCLLT 0x1C // SCL Low Time
@@ -273,6 +299,16 @@ struct npcm_i2c {
unsigned long int_time_stamp;
unsigned long bus_freq; // in kHz
u32 xmits;
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ u8 own_slave_addr;
+ struct i2c_client *slave;
+ int slv_rd_size;
+ int slv_rd_ind;
+ int slv_wr_size;
+ int slv_wr_ind;
+ u8 slv_rd_buf[I2C_HW_FIFO_SIZE];
+ u8 slv_wr_buf[I2C_HW_FIFO_SIZE];
+#endif
#if IS_ENABLED(CONFIG_DEBUG_FS)
struct dentry *debugfs;/* debugfs device directory */
uint64_t ber_count;
@@ -316,6 +352,10 @@ static void npcm_i2c_init_params(struct npcm_i2c *bus)
bus->int_time_stamp = 0;
bus->PEC_use = false;
bus->PEC_mask = 0;
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ if (bus->slave)
+ bus->master_or_slave = I2C_SLAVE;
+#endif
}
static inline void npcm_i2c_wr_byte(struct npcm_i2c *bus, u8 data)
@@ -363,6 +403,18 @@ static void npcm_i2c_disable(struct npcm_i2c *bus)
{
u8 i2cctl2;
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ int i;
+
+ // select bank 0 for I2C addresses
+ npcm_i2c_select_bank(bus, I2C_BANK_0);
+
+ // Slave addresses removal
+ for (i = I2C_SLAVE_ADDR1; i < I2C_NUM_OF_ADDR; i++)
+ iowrite8(0, bus->reg + npcm_i2caddr[i]);
+
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+#endif
// Disable module.
i2cctl2 = ioread8(bus->reg + NPCM_I2CCTL2);
i2cctl2 = i2cctl2 & ~I2CCTL2_ENABLE;
@@ -529,6 +581,63 @@ static inline void npcm_i2c_nack(struct npcm_i2c *bus)
iowrite8(val, bus->reg + NPCM_I2CCTL1);
}
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static void npcm_i2c_slave_int_enable(struct npcm_i2c *bus, bool enable)
+{
+ u8 i2cctl1;
+
+ // enable interrupt on slave match:
+ i2cctl1 = ioread8(bus->reg + NPCM_I2CCTL1);
+ i2cctl1 &= ~NPCM_I2CCTL1_RWS;
+ if (enable)
+ i2cctl1 |= NPCM_I2CCTL1_NMINTE;
+ else
+ i2cctl1 &= ~NPCM_I2CCTL1_NMINTE;
+ iowrite8(i2cctl1, bus->reg + NPCM_I2CCTL1);
+}
+
+static int npcm_i2c_slave_enable_l(struct npcm_i2c *bus,
+ enum i2c_addr addr_type, u8 addr,
+ bool enable)
+{
+ u8 i2cctl1;
+ u8 i2cctl3;
+ u8 sa_reg;
+
+ // npcm_i2c_slave_int_enable(bus, false);
+ sa_reg = (addr & 0x7F) | FIELD_PREP(NPCM_I2CADDR_SAEN, enable);
+ if (addr_type == I2C_GC_ADDR) {
+ i2cctl1 = ioread8(bus->reg + NPCM_I2CCTL1);
+ if (enable)
+ i2cctl1 |= NPCM_I2CCTL1_GCMEN;
+ else
+ i2cctl1 &= ~NPCM_I2CCTL1_GCMEN;
+ iowrite8(i2cctl1, bus->reg + NPCM_I2CCTL1);
+ return 0;
+ }
+ if (addr_type == I2C_ARP_ADDR) {
+ i2cctl3 = ioread8(bus->reg + NPCM_I2CCTL3);
+ if (enable)
+ i2cctl3 |= I2CCTL3_ARPMEN;
+ else
+ i2cctl3 &= ~I2CCTL3_ARPMEN;
+ iowrite8(i2cctl3, bus->reg + NPCM_I2CCTL3);
+ return 0;
+ }
+ if (addr_type >= I2C_ARP_ADDR)
+ return -EFAULT;
+ // select bank 0 for address 3 to 10
+ if (addr_type > I2C_SLAVE_ADDR2)
+ npcm_i2c_select_bank(bus, I2C_BANK_0);
+ // Set and enable the address
+ iowrite8(sa_reg, bus->reg + npcm_i2caddr[(int)addr_type]);
+ npcm_i2c_slave_int_enable(bus, enable);
+ if (addr_type > I2C_SLAVE_ADDR2)
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+ return 0;
+}
+#endif
+
static void npcm_i2c_reset(struct npcm_i2c *bus)
{
// Save I2CCTL1 relevant bits. It is being cleared when the module
@@ -556,6 +665,12 @@ static void npcm_i2c_reset(struct npcm_i2c *bus)
// Clear all fifo bits:
iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO, bus->reg + NPCM_I2CFIF_CTS);
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ if (bus->slave)
+ npcm_i2c_slave_enable_l(bus, I2C_SLAVE_ADDR1, bus->slave->addr,
+ true);
+#endif
+
bus->state = I2C_IDLE;
}
@@ -620,6 +735,10 @@ static void npcm_i2c_callback(struct npcm_i2c *bus,
}
bus->operation = I2C_NO_OPER;
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ if (bus->slave)
+ bus->master_or_slave = I2C_SLAVE;
+#endif
}
static u32 npcm_i2c_fifo_usage(struct npcm_i2c *bus)
@@ -647,6 +766,33 @@ static void npcm_i2c_write_to_fifo_master(struct npcm_i2c *bus,
}
}
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static void npcm_i2c_write_to_fifo_slave(struct npcm_i2c *bus,
+ u16 max_bytes_to_send)
+{
+ // Fill the FIFO, while the FIFO is not full and there are more bytes to
+ // write
+ npcm_i2c_clear_fifo_int(bus);
+ npcm_i2c_clear_tx_fifo(bus);
+ iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
+
+ while ((max_bytes_to_send--) &&
+ (I2C_HW_FIFO_SIZE - npcm_i2c_fifo_usage(bus))) {
+
+ if (bus->slv_wr_size > 0) {
+ bus->slv_wr_ind = bus->slv_wr_ind % I2C_HW_FIFO_SIZE;
+ npcm_i2c_wr_byte(bus,
+ bus->slv_wr_buf[bus->slv_wr_ind]);
+ bus->slv_wr_ind++;
+ bus->slv_wr_ind = bus->slv_wr_ind % I2C_HW_FIFO_SIZE;
+ bus->slv_wr_size--; // size indicates the # of bytes in
+ // the SW buffer, not HW fifo.
+ } else {
+ break;
+ }
+ }
+}
+#endif
/*
* configure the FIFO before using it. If nread is -1 RX FIFO will not be
* configured. same for nwrite
@@ -705,6 +851,21 @@ static void npcm_i2c_read_from_fifo(struct npcm_i2c *bus, u8 bytes_in_fifo)
if (bus->rd_ind < bus->rd_size)
bus->rd_buf[bus->rd_ind++] = data;
}
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ else {
+ if (bus->slave) {
+ bus->slv_rd_ind = bus->slv_rd_ind %
+ I2C_HW_FIFO_SIZE;
+ bus->slv_rd_buf[bus->slv_rd_ind] = data;
+ bus->slv_rd_ind++;
+ if (bus->slv_rd_ind == 1 && bus->read_block_use)
+ // 1st byte is length in block protocol
+ bus->slv_rd_size = data +
+ (u8)bus->PEC_use +
+ (u8)bus->read_block_use;
+ }
+ }
+#endif
}
}
@@ -727,6 +888,433 @@ static void npcm_i2c_master_abort(struct npcm_i2c *bus)
}
}
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static u8 npcm_i2c_get_slave_addr(struct npcm_i2c *bus,
+ enum i2c_addr addr_type)
+{
+ u8 slave_add;
+
+ // select bank 0 for address 3 to 10
+ if (addr_type > I2C_SLAVE_ADDR2)
+ npcm_i2c_select_bank(bus, I2C_BANK_0);
+
+ slave_add = ioread8(bus->reg + npcm_i2caddr[(int)addr_type]);
+
+ if (addr_type > I2C_SLAVE_ADDR2)
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+
+ return slave_add;
+}
+
+static int npcm_i2c_remove_slave_addr(struct npcm_i2c *bus, u8 slave_add)
+{
+ int i;
+
+ // Set the enable bit
+ slave_add |= 0x80;
+ npcm_i2c_select_bank(bus, I2C_BANK_0);
+ for (i = I2C_SLAVE_ADDR1; i < I2C_NUM_OF_ADDR; i++) {
+ if (ioread8(bus->reg + npcm_i2caddr[i]) == slave_add)
+ iowrite8(0, bus->reg + npcm_i2caddr[i]);
+ }
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+ return 0;
+}
+
+static int npcm_i2c_slave_get_wr_buf(struct npcm_i2c *bus)
+{
+ int i;
+ u8 value = 0;
+ int ret = bus->slv_wr_ind;
+
+ // fill a cyclic buffer
+ for (i = 0; i < I2C_HW_FIFO_SIZE; i++) {
+ if (bus->slv_wr_size >= I2C_HW_FIFO_SIZE)
+ break;
+ i2c_slave_event(bus->slave, I2C_SLAVE_READ_REQUESTED, &value);
+ bus->slv_wr_buf[(bus->slv_wr_ind + bus->slv_wr_size) %
+ I2C_HW_FIFO_SIZE] = value;
+ bus->slv_wr_size++;
+ i2c_slave_event(bus->slave, I2C_SLAVE_READ_PROCESSED, &value);
+ }
+ return I2C_HW_FIFO_SIZE - ret;
+}
+
+static void npcm_i2c_slave_send_rd_buf(struct npcm_i2c *bus)
+{
+ int i;
+
+ for (i = 0; i < bus->slv_rd_ind; i++)
+ i2c_slave_event(bus->slave, I2C_SLAVE_WRITE_RECEIVED,
+ &bus->slv_rd_buf[i]);
+
+ // once we send bytes up, need to reset the counter of the wr buf
+ // got data from master (new offset in device), ignore wr fifo:
+ if (bus->slv_rd_ind) {
+ bus->slv_wr_size = 0;
+ bus->slv_wr_ind = 0;
+ }
+
+ bus->slv_rd_ind = 0;
+ bus->slv_rd_size = bus->adap.quirks->max_read_len;
+
+ npcm_i2c_clear_fifo_int(bus);
+ npcm_i2c_clear_rx_fifo(bus);
+}
+
+static bool npcm_i2c_slave_receive(struct npcm_i2c *bus, u16 nread,
+ u8 *read_data)
+{
+ bus->state = I2C_OPER_STARTED;
+ bus->operation = I2C_READ_OPER;
+ bus->slv_rd_size = nread;
+ bus->slv_rd_ind = 0;
+
+ iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
+ iowrite8(I2C_HW_FIFO_SIZE, bus->reg + NPCM_I2CRXF_CTL);
+
+ npcm_i2c_clear_tx_fifo(bus);
+ npcm_i2c_clear_rx_fifo(bus);
+
+ return true;
+}
+
+static bool npcm_i2c_slave_xmit(struct npcm_i2c *bus, u16 nwrite,
+ u8 *write_data)
+{
+ if (nwrite == 0)
+ return false;
+
+ bus->state = I2C_OPER_STARTED;
+ bus->operation = I2C_WRITE_OPER;
+
+ // get the next buffer
+ npcm_i2c_slave_get_wr_buf(bus);
+
+ if (nwrite > 0)
+ npcm_i2c_write_to_fifo_slave(bus, nwrite);
+
+ return true;
+}
+
+/*
+ * currently slave IF only supports single byte operations.
+ * in order to utilyze the npcm HW FIFO, the driver will ask for 16 bytes
+ * at a time, pack them in buffer, and then transmit them all together
+ * to the FIFO and onward to the bus.
+ * NACK on read will be once reached to bus->adap->quirks->max_read_len.
+ * sending a NACK wherever the backend requests for it is not supported.
+ * the next two functions allow reading to local buffer before writing it all
+ * to the HW FIFO.
+ * ret val: number of bytes read from the IF:
+ */
+static int npcm_i2c_slave_wr_buf_sync(struct npcm_i2c *bus)
+{
+ int left_in_fifo;
+
+ left_in_fifo = FIELD_GET(NPCM_I2CTXF_STS_TX_BYTES,
+ ioread8(bus->reg + NPCM_I2CTXF_STS));
+ if (left_in_fifo >= I2C_HW_FIFO_SIZE)
+ return left_in_fifo;
+
+ // fifo already full:
+ if (bus->slv_wr_size >= I2C_HW_FIFO_SIZE)
+ return left_in_fifo;
+
+ // update the wr fifo ind, back to the untransmitted bytes:
+ bus->slv_wr_ind = bus->slv_wr_ind - left_in_fifo;
+ bus->slv_wr_size = bus->slv_wr_size + left_in_fifo;
+
+ if (bus->slv_wr_ind < 0)
+ bus->slv_wr_ind += I2C_HW_FIFO_SIZE;
+
+ return left_in_fifo;
+}
+
+static void npcm_i2c_slave_rd_wr(struct npcm_i2c *bus)
+{
+ if (FIELD_GET(NPCM_I2CST_XMIT, ioread8(bus->reg + NPCM_I2CST))) {
+ /*
+ * Slave got an address match with direction bit 1 so
+ * it should transmit data
+ * Write till the master will NACK
+ */
+ bus->operation = I2C_WRITE_OPER;
+ npcm_i2c_slave_xmit(bus,
+ bus->adap.quirks->max_write_len,
+ bus->slv_wr_buf);
+ } else {
+ /*
+ * Slave got an address match with direction bit 0
+ * so it should receive data.
+ * this module does not support saying no to bytes.
+ * it will always ACK.
+ */
+ bus->operation = I2C_READ_OPER;
+ npcm_i2c_read_from_fifo(bus, npcm_i2c_fifo_usage(bus));
+ bus->stop_ind = I2C_SLAVE_RCV_IND;
+ npcm_i2c_slave_send_rd_buf(bus);
+ npcm_i2c_slave_receive(bus,
+ bus->adap.quirks->max_read_len,
+ bus->slv_rd_buf);
+ }
+}
+
+static irqreturn_t npcm_i2c_int_slave_handler(struct npcm_i2c *bus)
+{
+ u8 val;
+ irqreturn_t ret = IRQ_NONE;
+ u8 i2cst = ioread8(bus->reg + NPCM_I2CST);
+
+ // Slave: A NACK has occurred
+ if (FIELD_GET(NPCM_I2CST_NEGACK, i2cst)) {
+ bus->stop_ind = I2C_NACK_IND;
+ npcm_i2c_slave_wr_buf_sync(bus);
+ if (bus->fifo_use)
+ // clear the FIFO
+ iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO,
+ bus->reg + NPCM_I2CFIF_CTS);
+
+ // In slave write, NACK is OK, otherwise it is a problem
+ bus->stop_ind = I2C_NO_STATUS_IND;
+ bus->operation = I2C_NO_OPER;
+ bus->own_slave_addr = 0xFF;
+
+ /*
+ * Slave has to wait for I2C_STOP to decide this is the end
+ * of the transaction.
+ * Therefore transaction is not yet considered as done
+ */
+ iowrite8(NPCM_I2CST_NEGACK, bus->reg + NPCM_I2CST);
+
+ ret = IRQ_HANDLED;
+ }
+
+ // Slave mode: a Bus Error (BER) has been identified
+ if (FIELD_GET(NPCM_I2CST_BER, i2cst)) {
+ // Check whether bus arbitration or Start or Stop during data
+ // xfer bus arbitration problem should not result in recovery
+ bus->stop_ind = I2C_BUS_ERR_IND;
+
+ // wait for bus busy before clear fifo
+ iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO, bus->reg + NPCM_I2CFIF_CTS);
+
+ bus->state = I2C_IDLE;
+
+ // in BER case we might get 2 interrupts: one for slave one for
+ // master ( for a channel which is master\slave switching)
+ if (completion_done(&bus->cmd_complete) == false) {
+ bus->cmd_err = -EIO;
+ complete(&bus->cmd_complete);
+ }
+ bus->own_slave_addr = 0xFF;
+ iowrite8(NPCM_I2CST_BER, bus->reg + NPCM_I2CST);
+ ret = IRQ_HANDLED;
+ }
+
+ // A Slave Stop Condition has been identified
+ if (FIELD_GET(NPCM_I2CST_SLVSTP, i2cst)) {
+ int bytes_in_fifo = npcm_i2c_fifo_usage(bus);
+
+ bus->stop_ind = I2C_SLAVE_DONE_IND;
+
+ if (bus->operation == I2C_READ_OPER) {
+ npcm_i2c_read_from_fifo(bus, bytes_in_fifo);
+
+ // Slave done transmitting or receiving
+ // if the buffer is empty nothing will be sent
+ }
+
+ // Slave done transmitting or receiving
+ // if the buffer is empty nothing will be sent
+ npcm_i2c_slave_send_rd_buf(bus);
+
+ bus->stop_ind = I2C_NO_STATUS_IND;
+
+ /*
+ * Note, just because we got here, it doesn't mean we through
+ * away the wr buffer.
+ * we keep it until the next received offset.
+ */
+ bus->operation = I2C_NO_OPER;
+ bus->int_cnt = 0;
+ bus->own_slave_addr = 0xFF;
+ i2c_slave_event(bus->slave, I2C_SLAVE_STOP, 0);
+ iowrite8(NPCM_I2CST_SLVSTP, bus->reg + NPCM_I2CST);
+ if (bus->fifo_use) {
+ npcm_i2c_clear_fifo_int(bus);
+ npcm_i2c_clear_rx_fifo(bus);
+ npcm_i2c_clear_tx_fifo(bus);
+
+ iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO,
+ bus->reg + NPCM_I2CFIF_CTS);
+ }
+ bus->state = I2C_IDLE;
+ ret = IRQ_HANDLED;
+ }
+
+ // restart condition occurred and Rx-FIFO was not empty
+ if (bus->fifo_use && FIELD_GET(NPCM_I2CFIF_CTS_SLVRSTR,
+ ioread8(bus->reg + NPCM_I2CFIF_CTS))) {
+ bus->stop_ind = I2C_SLAVE_RESTART_IND;
+ bus->master_or_slave = I2C_SLAVE;
+ if (bus->operation == I2C_READ_OPER)
+ npcm_i2c_read_from_fifo(bus, npcm_i2c_fifo_usage(bus));
+ bus->operation = I2C_WRITE_OPER;
+ iowrite8(0, bus->reg + NPCM_I2CRXF_CTL);
+ val = NPCM_I2CFIF_CTS_CLR_FIFO | NPCM_I2CFIF_CTS_SLVRSTR |
+ NPCM_I2CFIF_CTS_RXF_TXE;
+ iowrite8(val, bus->reg + NPCM_I2CFIF_CTS);
+ npcm_i2c_slave_rd_wr(bus);
+ ret = IRQ_HANDLED;
+ }
+
+ // A Slave Address Match has been identified
+ if (FIELD_GET(NPCM_I2CST_NMATCH, i2cst)) {
+ u8 info = 0;
+
+ // Address match automatically implies slave mode
+ bus->master_or_slave = I2C_SLAVE;
+ npcm_i2c_clear_fifo_int(bus);
+ npcm_i2c_clear_rx_fifo(bus);
+ npcm_i2c_clear_tx_fifo(bus);
+ iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
+ iowrite8(I2C_HW_FIFO_SIZE, bus->reg + NPCM_I2CRXF_CTL);
+ if (FIELD_GET(NPCM_I2CST_XMIT, i2cst)) {
+ bus->operation = I2C_WRITE_OPER;
+ } else {
+ i2c_slave_event(bus->slave, I2C_SLAVE_WRITE_REQUESTED,
+ &info);
+ bus->operation = I2C_READ_OPER;
+ }
+ if (bus->own_slave_addr == 0xFF) { // unknown address
+ // Check which type of address match
+ val = ioread8(bus->reg + NPCM_I2CCST);
+ if (!!(NPCM_I2CCST_MATCH & val)) {
+ u16 addr;
+ enum i2c_addr eaddr;
+ u8 i2ccst2;
+ u8 i2ccst3;
+
+ i2ccst3 = ioread8(bus->reg + NPCM_I2CCST3);
+ i2ccst2 = ioread8(bus->reg + NPCM_I2CCST2);
+
+ // the i2c module can response to 10 own SA.
+ // check which one was addressed by the master.
+ // repond to the first one.
+ addr = ((i2ccst3 & 0x07) << 7) |
+ (i2ccst2 & 0x7F);
+ info = ffs(addr);
+ eaddr = (enum i2c_addr)info;
+ addr = npcm_i2c_get_slave_addr(bus, eaddr);
+ addr &= 0x7F;
+ bus->own_slave_addr = addr;
+ if (bus->PEC_mask & BIT(info))
+ bus->PEC_use = true;
+ else
+ bus->PEC_use = false;
+ } else {
+ val = ioread8(bus->reg + NPCM_I2CCST);
+ if (!!(NPCM_I2CCST_GCMATCH & val))
+ bus->own_slave_addr = 0;
+ if (!!(NPCM_I2CCST_ARPMATCH & val))
+ bus->own_slave_addr = 0x61;
+ }
+ } else {
+ /*
+ * Slave match can happen in two options:
+ * 1. Start, SA, read (slave read without further ado)
+ * 2. Start, SA, read, data, restart, SA, read, ...
+ * (slave read in fragmented mode)
+ * 3. Start, SA, write, data, restart, SA, read, ..
+ * (regular write-read mode)
+ */
+ if ((bus->state == I2C_OPER_STARTED &&
+ bus->operation == I2C_READ_OPER &&
+ bus->stop_ind == I2C_SLAVE_XMIT_IND) ||
+ bus->stop_ind == I2C_SLAVE_RCV_IND) {
+ // slave transmit after slave receive w/o Slave
+ // Stop implies repeated start
+ bus->stop_ind = I2C_SLAVE_RESTART_IND;
+ }
+ }
+
+ if (FIELD_GET(NPCM_I2CST_XMIT, i2cst))
+ bus->stop_ind = I2C_SLAVE_XMIT_IND;
+ else
+ bus->stop_ind = I2C_SLAVE_RCV_IND;
+ bus->state = I2C_SLAVE_MATCH;
+ npcm_i2c_slave_rd_wr(bus);
+ iowrite8(NPCM_I2CST_NMATCH, bus->reg + NPCM_I2CST);
+ ret = IRQ_HANDLED;
+ }
+
+ // Slave SDA status is set - transmit or receive, slave
+ if (FIELD_GET(NPCM_I2CST_SDAST, i2cst) ||
+ (bus->fifo_use &&
+ (npcm_i2c_tx_fifo_empty(bus) || npcm_i2c_rx_fifo_full(bus)))) {
+ npcm_i2c_slave_rd_wr(bus);
+ iowrite8(NPCM_I2CST_SDAST, bus->reg + NPCM_I2CST);
+ ret = IRQ_HANDLED;
+ } //SDAST
+
+ return ret;
+}
+
+static int npcm_i2c_reg_slave(struct i2c_client *client)
+{
+ unsigned long lock_flags;
+ struct npcm_i2c *bus = i2c_get_adapdata(client->adapter);
+
+ bus->slave = client;
+
+ if (!bus->slave)
+ return -EINVAL;
+
+ if (client->flags & I2C_CLIENT_TEN)
+ return -EAFNOSUPPORT;
+
+ spin_lock_irqsave(&bus->lock, lock_flags);
+
+ npcm_i2c_init_params(bus);
+ bus->slv_rd_size = 0;
+ bus->slv_wr_size = 0;
+ bus->slv_rd_ind = 0;
+ bus->slv_wr_ind = 0;
+ if (client->flags & I2C_CLIENT_PEC)
+ bus->PEC_use = true;
+
+ dev_info(bus->dev, "i2c%d register slave SA=0x%x, PEC=%d\n", bus->num,
+ client->addr, bus->PEC_use);
+
+ npcm_i2c_slave_enable_l(bus, I2C_SLAVE_ADDR1, client->addr, true);
+ npcm_i2c_clear_fifo_int(bus);
+ npcm_i2c_clear_rx_fifo(bus);
+ npcm_i2c_clear_tx_fifo(bus);
+ npcm_i2c_slave_int_enable(bus, true);
+
+ spin_unlock_irqrestore(&bus->lock, lock_flags);
+ return 0;
+}
+
+static int npcm_i2c_unreg_slave(struct i2c_client *client)
+{
+ struct npcm_i2c *bus = client->adapter->algo_data;
+ unsigned long lock_flags;
+
+ spin_lock_irqsave(&bus->lock, lock_flags);
+ if (!bus->slave) {
+ spin_unlock_irqrestore(&bus->lock, lock_flags);
+ return -EINVAL;
+ }
+ npcm_i2c_slave_int_enable(bus, false);
+ npcm_i2c_remove_slave_addr(bus, client->addr);
+ bus->slave = NULL;
+ spin_unlock_irqrestore(&bus->lock, lock_flags);
+ return 0;
+}
+#endif // CONFIG_I2C_SLAVE
+
static void npcm_i2c_master_fifo_read(struct npcm_i2c *bus)
{
int rcount;
@@ -1393,6 +1981,9 @@ static int __npcm_i2c_init(struct npcm_i2c *bus, struct platform_device *pdev)
bus->state = I2C_DISABLE;
bus->master_or_slave = I2C_SLAVE;
bus->int_time_stamp = 0;
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ bus->slave = NULL;
+#endif
bus->xmits = 0;
ret = device_property_read_u32(&pdev->dev, "bus-frequency", &clk_freq);
@@ -1426,6 +2017,14 @@ static irqreturn_t npcm_i2c_bus_irq(int irq, void *dev_id)
if (ret == IRQ_HANDLED)
return ret;
}
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ if (bus->slave) {
+ bus->master_or_slave = I2C_SLAVE;
+ ret = npcm_i2c_int_slave_handler(bus);
+ if (ret == IRQ_HANDLED)
+ return ret;
+ }
+#endif
return IRQ_HANDLED;
}
@@ -1568,6 +2167,11 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
*/
spin_lock_irqsave(&bus->lock, flags);
bus_busy = ioread8(bus->reg + NPCM_I2CCST) & NPCM_I2CCST_BB;
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ if (!bus_busy && bus->slave)
+ iowrite8((bus->slave->addr & 0x7F),
+ bus->reg + NPCM_I2CADDR1);
+#endif
spin_unlock_irqrestore(&bus->lock, flags);
} while (time_is_after_jiffies(time_left) && bus_busy);
@@ -1620,6 +2224,12 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
if (bus->cmd_err == -EAGAIN)
ret = i2c_recover_bus(adap);
+#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);
+#endif
return bus->cmd_err;
}
@@ -1642,6 +2252,10 @@ static const struct i2c_adapter_quirks npcm_i2c_quirks = {
static const struct i2c_algorithm npcm_i2c_algo = {
.master_xfer = npcm_i2c_master_xfer,
.functionality = npcm_i2c_functionality,
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ .reg_slave = npcm_i2c_reg_slave,
+ .unreg_slave = npcm_i2c_unreg_slave,
+#endif
};
#if IS_ENABLED(CONFIG_DEBUG_FS)
--
2.22.0
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