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From:   Tyrone Ting <warp5tw@gmail.com>
To:     avifishman70@gmail.com, tmaimon77@gmail.com, tali.perry1@gmail.com,
        venture@google.com, yuenn@google.com, benjaminfair@google.com,
        robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org,
        wsa@kernel.org, andriy.shevchenko@linux.intel.com,
        jarkko.nikula@linux.intel.com, semen.protsenko@linaro.org,
        jie.deng@intel.com, jsd@semihalf.com, sven@svenpeter.dev,
        lukas.bulwahn@gmail.com, olof@lixom.net, arnd@arndb.de,
        warp5tw@gmail.com, tali.perry@nuvoton.com, Avi.Fishman@nuvoton.com,
        tomer.maimon@nuvoton.com, KWLIU@nuvoton.com, JJLIU0@nuvoton.com,
        kfting@nuvoton.com
Cc:     openbmc@lists.ozlabs.org, linux-i2c@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v6 4/5] i2c: npcm: Support NPCM845
Date:   Wed, 25 May 2022 11:23:40 +0800
Message-Id: <20220525032341.3182-5-warp5tw@gmail.com>
In-Reply-To: <20220525032341.3182-1-warp5tw@gmail.com>
References: <20220525032341.3182-1-warp5tw@gmail.com>
Precedence: bulk

From: Tyrone Ting <kfting@nuvoton.com>

Add NPCM8XX I2C support.
The NPCM8XX uses a similar i2c module as NPCM7XX.
The internal HW FIFO is larger in NPCM8XX.

Signed-off-by: Tyrone Ting <kfting@nuvoton.com>
Acked-by: Tomer Maimon <tmaimon77@gmail.com>
---
 drivers/i2c/busses/Kconfig       |   8 +--
 drivers/i2c/busses/Makefile      |   2 +-
 drivers/i2c/busses/i2c-npcm7xx.c | 114 +++++++++++++++++++------------
 3 files changed, 76 insertions(+), 48 deletions(-)

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index a1bae59208e3..b1d7069dd377 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -838,13 +838,13 @@ 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
+config I2C_NPCM
 	tristate "Nuvoton I2C Controller"
-	depends on ARCH_NPCM7XX || COMPILE_TEST
+	depends on ARCH_NPCM || 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.
+	  Nuvoton I2C controller, which is available on the NPCM BMC
+	  controllers.
 	  Driver can also support slave mode (select I2C_SLAVE).
 
 config I2C_OCORES
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 479f60e4ee3d..b0a10e5d9ee9 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -84,7 +84,7 @@ 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_NPCM)		+= 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
index b4d218c6c8fb..86fd942ea648 100644
--- a/drivers/i2c/busses/i2c-npcm7xx.c
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -17,6 +17,7 @@
 #include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 
@@ -91,7 +92,6 @@ enum i2c_addr {
 
 /* 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
@@ -226,8 +226,7 @@ static const int npcm_i2caddr[I2C_NUM_OWN_ADDR] = {
 #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)
+/* NPCM_I2CTXF_CTL reg field */
 #define NPCM_I2CTXF_CTL_THR_TXIE	BIT(6)
 
 /* NPCM_I2CT_OUT reg fields */
@@ -236,22 +235,18 @@ static const int npcm_i2caddr[I2C_NUM_OWN_ADDR] = {
 #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
+#define MAX_I2C_HW_FIFO_SIZE		32
 
 /* I2C_VER reg fields */
 #define I2C_VER_VERSION			GENMASK(6, 0)
@@ -268,11 +263,36 @@ static const int npcm_i2caddr[I2C_NUM_OWN_ADDR] = {
 #define I2C_FREQ_MIN_HZ			10000
 #define I2C_FREQ_MAX_HZ			I2C_MAX_FAST_MODE_PLUS_FREQ
 
+struct npcm_i2c_data {
+	u8 fifo_size;
+	u32 segctl_init_val;
+	u8 txf_sts_tx_bytes;
+	u8 rxf_sts_rx_bytes;
+	u8 rxf_ctl_last_pec;
+};
+
+static const struct npcm_i2c_data npxm7xx_i2c_data = {
+	.fifo_size = 16,
+	.segctl_init_val = 0x0333F000,
+	.txf_sts_tx_bytes = GENMASK(4, 0),
+	.rxf_sts_rx_bytes = GENMASK(4, 0),
+	.rxf_ctl_last_pec = BIT(5),
+};
+
+static const struct npcm_i2c_data npxm8xx_i2c_data = {
+	.fifo_size = 32,
+	.segctl_init_val = 0x9333F000,
+	.txf_sts_tx_bytes = GENMASK(5, 0),
+	.rxf_sts_rx_bytes = GENMASK(5, 0),
+	.rxf_ctl_last_pec = BIT(7),
+};
+
 /* Status of one I2C module */
 struct npcm_i2c {
 	struct i2c_adapter adap;
 	struct device *dev;
 	unsigned char __iomem *reg;
+	const struct npcm_i2c_data *data;
 	spinlock_t lock;   /* IRQ synchronization */
 	struct completion cmd_complete;
 	int cmd_err;
@@ -305,8 +325,8 @@ struct npcm_i2c {
 	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];
+	u8 slv_rd_buf[MAX_I2C_HW_FIFO_SIZE];
+	u8 slv_wr_buf[MAX_I2C_HW_FIFO_SIZE];
 #endif
 	struct dentry *debugfs; /* debugfs device directory */
 	u64 ber_cnt;
@@ -439,7 +459,7 @@ static inline bool npcm_i2c_tx_fifo_empty(struct npcm_i2c *bus)
 
 	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)
+	if ((tx_fifo_sts & bus->data->txf_sts_tx_bytes) == 0)
 		return false;
 
 	/* check if TX FIFO status bit is set: */
@@ -452,7 +472,7 @@ static inline bool npcm_i2c_rx_fifo_full(struct npcm_i2c *bus)
 
 	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)
+	if ((rx_fifo_sts & bus->data->rxf_sts_rx_bytes) == 0)
 		return false;
 
 	/* check if rx fifo full status is set: */
@@ -739,11 +759,11 @@ static void npcm_i2c_callback(struct npcm_i2c *bus,
 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));
+		return (bus->data->txf_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 (bus->data->rxf_sts_rx_bytes &
+			ioread8(bus->reg + NPCM_I2CRXF_STS));
 	return 0;
 }
 
@@ -755,13 +775,13 @@ static void npcm_i2c_write_to_fifo_master(struct npcm_i2c *bus, u16 max_bytes)
 	 * 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);
+	size_free_fifo = bus->data->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);
+		size_free_fifo = bus->data->fifo_size - npcm_i2c_fifo_usage(bus);
 	}
 }
 
@@ -782,11 +802,11 @@ static void npcm_i2c_set_fifo(struct npcm_i2c *bus, int nread, int nwrite)
 
 	/* configure RX FIFO */
 	if (nread > 0) {
-		rxf_ctl = min_t(int, nread, I2C_HW_FIFO_SIZE);
+		rxf_ctl = min_t(int, nread, bus->data->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 (nread <= bus->data->fifo_size)
+			rxf_ctl |= bus->data->rxf_ctl_last_pec;
 
 		/*
 		 * if we are about to read the first byte in blk rd mode,
@@ -804,9 +824,9 @@ static void npcm_i2c_set_fifo(struct npcm_i2c *bus, int nread, int nwrite)
 
 	/* configure TX FIFO */
 	if (nwrite > 0) {
-		if (nwrite > I2C_HW_FIFO_SIZE)
+		if (nwrite > bus->data->fifo_size)
 			/* data to send is more then FIFO size. */
-			iowrite8(I2C_HW_FIFO_SIZE, bus->reg + NPCM_I2CTXF_CTL);
+			iowrite8(bus->data->fifo_size, bus->reg + NPCM_I2CTXF_CTL);
 		else
 			iowrite8(nwrite, bus->reg + NPCM_I2CTXF_CTL);
 
@@ -873,13 +893,13 @@ static void npcm_i2c_write_fifo_slave(struct npcm_i2c *bus, u16 max_bytes)
 	npcm_i2c_clear_fifo_int(bus);
 	npcm_i2c_clear_tx_fifo(bus);
 	iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
-	while (max_bytes-- && I2C_HW_FIFO_SIZE != npcm_i2c_fifo_usage(bus)) {
+	while (max_bytes-- && bus->data->fifo_size != npcm_i2c_fifo_usage(bus)) {
 		if (bus->slv_wr_size <= 0)
 			break;
-		bus->slv_wr_ind = bus->slv_wr_ind % I2C_HW_FIFO_SIZE;
+		bus->slv_wr_ind = bus->slv_wr_ind & (bus->data->fifo_size - 1);
 		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_ind = bus->slv_wr_ind & (bus->data->fifo_size - 1);
 		bus->slv_wr_size--;
 	}
 }
@@ -894,7 +914,7 @@ static void npcm_i2c_read_fifo_slave(struct npcm_i2c *bus, u8 bytes_in_fifo)
 	while (bytes_in_fifo--) {
 		data = npcm_i2c_rd_byte(bus);
 
-		bus->slv_rd_ind = bus->slv_rd_ind % I2C_HW_FIFO_SIZE;
+		bus->slv_rd_ind = bus->slv_rd_ind & (bus->data->fifo_size - 1);
 		bus->slv_rd_buf[bus->slv_rd_ind] = data;
 		bus->slv_rd_ind++;
 
@@ -912,8 +932,8 @@ static int npcm_i2c_slave_get_wr_buf(struct npcm_i2c *bus)
 	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)
+	for (i = 0; i < bus->data->fifo_size; i++) {
+		if (bus->slv_wr_size >= bus->data->fifo_size)
 			break;
 		if (bus->state == I2C_SLAVE_MATCH) {
 			i2c_slave_event(bus->slave, I2C_SLAVE_READ_REQUESTED, &value);
@@ -921,11 +941,11 @@ static int npcm_i2c_slave_get_wr_buf(struct npcm_i2c *bus)
 		} else {
 			i2c_slave_event(bus->slave, I2C_SLAVE_READ_PROCESSED, &value);
 		}
-		ind = (bus->slv_wr_ind + bus->slv_wr_size) % I2C_HW_FIFO_SIZE;
+		ind = (bus->slv_wr_ind + bus->slv_wr_size) & (bus->data->fifo_size - 1);
 		bus->slv_wr_buf[ind] = value;
 		bus->slv_wr_size++;
 	}
-	return I2C_HW_FIFO_SIZE - ret;
+	return bus->data->fifo_size - ret;
 }
 
 static void npcm_i2c_slave_send_rd_buf(struct npcm_i2c *bus)
@@ -960,7 +980,7 @@ static void npcm_i2c_slave_receive(struct npcm_i2c *bus, u16 nread,
 	bus->slv_rd_ind = 0;
 
 	iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
-	iowrite8(I2C_HW_FIFO_SIZE, bus->reg + NPCM_I2CRXF_CTL);
+	iowrite8(bus->data->fifo_size, bus->reg + NPCM_I2CRXF_CTL);
 	npcm_i2c_clear_tx_fifo(bus);
 	npcm_i2c_clear_rx_fifo(bus);
 }
@@ -993,12 +1013,12 @@ static void 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));
+	left_in_fifo = bus->data->txf_sts_tx_bytes &
+			ioread8(bus->reg + NPCM_I2CTXF_STS);
 
 	/* fifo already full: */
-	if (left_in_fifo >= I2C_HW_FIFO_SIZE ||
-	    bus->slv_wr_size >= I2C_HW_FIFO_SIZE)
+	if (left_in_fifo >= bus->data->fifo_size ||
+	    bus->slv_wr_size >= bus->data->fifo_size)
 		return;
 
 	/* update the wr fifo index back to the untransmitted bytes: */
@@ -1006,7 +1026,7 @@ static void npcm_i2c_slave_wr_buf_sync(struct npcm_i2c *bus)
 	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;
+		bus->slv_wr_ind += bus->data->fifo_size;
 }
 
 static void npcm_i2c_slave_rd_wr(struct npcm_i2c *bus)
@@ -1152,7 +1172,7 @@ static irqreturn_t npcm_i2c_int_slave_handler(struct npcm_i2c *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);
+		iowrite8(bus->data->fifo_size, bus->reg + NPCM_I2CRXF_CTL);
 		if (NPCM_I2CST_XMIT & i2cst) {
 			bus->operation = I2C_WRITE_OPER;
 		} else {
@@ -1313,8 +1333,8 @@ static void npcm_i2c_master_fifo_read(struct npcm_i2c *bus)
 	 * 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 < (2 * bus->data->fifo_size) && rcount > bus->data->fifo_size)
+		fifo_bytes = rcount - bus->data->fifo_size;
 
 	if (rcount <= fifo_bytes) {
 		/* last bytes are about to be read - end of tx */
@@ -2193,7 +2213,7 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 	 * It cannot be cleared without resetting the module.
 	 */
 	else if (bus->cmd_err &&
-		 (NPCM_I2CRXF_CTL_LAST_PEC & ioread8(bus->reg + NPCM_I2CRXF_CTL)))
+		 (bus->data->rxf_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 */
@@ -2262,6 +2282,7 @@ static int npcm_i2c_probe_bus(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
 	static struct regmap *gcr_regmap;
+	struct device *dev = &pdev->dev;
 	struct i2c_adapter *adap;
 	struct npcm_i2c *bus;
 	struct clk *i2c_clk;
@@ -2274,6 +2295,12 @@ static int npcm_i2c_probe_bus(struct platform_device *pdev)
 
 	bus->dev = &pdev->dev;
 
+	bus->data = of_device_get_match_data(dev);
+	if (!bus->data) {
+		dev_err(dev, "OF data missing\n");
+		return -EINVAL;
+	}
+
 	bus->num = of_alias_get_id(pdev->dev.of_node, "i2c");
 	/* core clk must be acquired to calculate module timing settings */
 	i2c_clk = devm_clk_get(&pdev->dev, NULL);
@@ -2287,7 +2314,7 @@ static int npcm_i2c_probe_bus(struct platform_device *pdev)
 
 	if (IS_ERR(gcr_regmap))
 		return PTR_ERR(gcr_regmap);
-	regmap_write(gcr_regmap, NPCM_I2CSEGCTL, NPCM_I2CSEGCTL_INIT_VAL);
+	regmap_write(gcr_regmap, NPCM_I2CSEGCTL, bus->data->segctl_init_val);
 
 	bus->reg = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(bus->reg))
@@ -2349,7 +2376,8 @@ static int npcm_i2c_remove_bus(struct platform_device *pdev)
 }
 
 static const struct of_device_id npcm_i2c_bus_of_table[] = {
-	{ .compatible = "nuvoton,npcm750-i2c", },
+	{ .compatible = "nuvoton,npcm750-i2c", .data = &npxm7xx_i2c_data },
+	{ .compatible = "nuvoton,npcm845-i2c", .data = &npxm8xx_i2c_data },
 	{}
 };
 MODULE_DEVICE_TABLE(of, npcm_i2c_bus_of_table);
-- 
2.17.1