[PATCH v2 11/11] i2c: npcm: Support NPCM845

[Tyrone Ting <warp5tw@gmail.com>]

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>
Signed-off-by: Tali Perry <tali.perry1@gmail.com>
---
 drivers/i2c/busses/Kconfig       |  8 +--
 drivers/i2c/busses/Makefile      |  2 +-
 drivers/i2c/busses/i2c-npcm7xx.c | 87 ++++++++++++++++++++++----------
 3 files changed, 66 insertions(+), 31 deletions(-)

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 42da31c1ab70..ab9ee2de5e00 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -817,13 +817,13 @@ 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 1d00dce77098..01fdf74a5565 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -80,7 +80,7 @@ obj-$(CONFIG_I2C_MT7621)	+= i2c-mt7621.o
 obj-$(CONFIG_I2C_MV64XXX)	+= i2c-mv64xxx.o
 obj-$(CONFIG_I2C_MXS)		+= i2c-mxs.o
 obj-$(CONFIG_I2C_NOMADIK)	+= i2c-nomadik.o
-obj-$(CONFIG_I2C_NPCM7XX)	+= i2c-npcm7xx.o
+obj-$(CONFIG_I2C_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 2cbf9c679aed..b281e0424e3e 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 +92,7 @@ enum i2c_addr {
 
 /* init register and default value required to enable module */
 #define NPCM_I2CSEGCTL			0xE4
-#define NPCM_I2CSEGCTL_INIT_VAL		0x0333F000
+#define NPCM_I2CSEGCTL_INIT_VAL		bus->data->segctl_init_val
 
 /* Common regs */
 #define NPCM_I2CSDA			0x00
@@ -228,8 +229,7 @@ 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 */
@@ -238,22 +238,22 @@ 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_BYTES	bus->data->txf_sts_tx_bytes
 #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_BYTES	bus->data->rxf_sts_rx_bytes
 #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_LAST_PEC	bus->data->rxf_ctl_last_pec
 #define NPCM_I2CRXF_CTL_THR_RXIE	BIT(6)
 
-#define I2C_HW_FIFO_SIZE		16
+#define MAX_I2C_HW_FIFO_SIZE		32
+#define I2C_HW_FIFO_SIZE		bus->data->fifo_size
 
 /* I2C_VER reg fields */
 #define I2C_VER_VERSION			GENMASK(6, 0)
@@ -270,11 +270,36 @@ 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;
@@ -307,8 +332,8 @@ 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;
@@ -743,11 +768,11 @@ 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 (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 (NPCM_I2CRXF_STS_RX_BYTES &
+			ioread8(bus->reg + NPCM_I2CRXF_STS));
 	return 0;
 }
 
@@ -882,10 +907,10 @@ static void npcm_i2c_write_fifo_slave(struct npcm_i2c *bus, u16 max_bytes)
 	while (max_bytes-- && I2C_HW_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 & (I2C_HW_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 & (I2C_HW_FIFO_SIZE - 1);
 		bus->slv_wr_size--;
 	}
 }
@@ -900,7 +925,7 @@ 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 & (I2C_HW_FIFO_SIZE - 1);
 		bus->slv_rd_buf[bus->slv_rd_ind] = data;
 		bus->slv_rd_ind++;
 
@@ -927,7 +952,7 @@ 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) & (I2C_HW_FIFO_SIZE - 1);
 		bus->slv_wr_buf[ind] = value;
 		bus->slv_wr_size++;
 	}
@@ -999,8 +1024,8 @@ 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 = (NPCM_I2CTXF_STS_TX_BYTES &
+			ioread8(bus->reg + NPCM_I2CTXF_STS));
 
 	/* fifo already full: */
 	if (left_in_fifo >= I2C_HW_FIFO_SIZE ||
@@ -2265,12 +2290,21 @@ static void npcm_i2c_init_debugfs(struct platform_device *pdev,
 	bus->debugfs = d;
 }
 
+static const struct of_device_id npcm_i2c_bus_of_table[] = {
+	{ .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);
+
 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;
+	struct device *dev = &pdev->dev;
+	const struct of_device_id *match;
 	int irq;
 	int ret;
 	struct device_node *np = pdev->dev.of_node;
@@ -2281,6 +2315,13 @@ static int npcm_i2c_probe_bus(struct platform_device *pdev)
 
 	bus->dev = &pdev->dev;
 
+	match = of_match_device(npcm_i2c_bus_of_table, dev);
+	if (!match) {
+		dev_err(dev, "OF data missing\n");
+		return -EINVAL;
+	}
+	bus->data = match->data;
+
 	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);
@@ -2352,12 +2393,6 @@ static int npcm_i2c_remove_bus(struct platform_device *pdev)
 	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,
-- 
2.17.1