[RESEND PATCH 0/4] Add-Broadcom-Kona-I2C-Support

[RESEND PATCH 0/4] Add-Broadcom-Kona-I2C-Support

[Tim Kryger]

This series adds support for the Kona I2C bus found on Broadcom mobile
SoCs like the bcm11351 (aka bcm281xx) and enables it on the bcm28155-ap
board.

It depends upon the following commits:
  https://lkml.org/lkml/2013/10/7/481
  http://www.spinics.net/lists/arm-kernel/msg274964.html

Tim Kryger (4):
  i2c: i2c-bcm-kona: Introduce Broadcom I2C Driver
  i2c: i2c-bcm-kona: Add support for high-speed mode
  ARM: dts: bcm281xx: Add i2c busses
  ARM: dts: bcm28155-ap: Enable all the i2c busses

 .../devicetree/bindings/i2c/i2c-bcm-kona.txt       |  30 +
 arch/arm/boot/dts/bcm11351.dtsi                    |  40 +
 arch/arm/boot/dts/bcm28155-ap.dts                  |  20 +
 drivers/i2c/busses/Kconfig                         |  10 +
 drivers/i2c/busses/Makefile                        |   1 +
 drivers/i2c/busses/i2c-bcm-kona.c                  | 936 +++++++++++++++++++++
 6 files changed, 1037 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/i2c/i2c-bcm-kona.txt
 create mode 100644 drivers/i2c/busses/i2c-bcm-kona.c

-- 
1.8.0.1

[RESEND PATCH 1/4] i2c: i2c-bcm-kona: Introduce Broadcom I2C Driver

[Tim Kryger]

Introduce support for Broadcom Serial Controller (BSC) I2C bus found
in the Kona family of Mobile SoCs.  FIFO hardware is utilized but only
standard mode (100kHz), fast mode (400kHz), and fast mode plus (1MHz)
bus speeds are supported.

Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <matt.porter@linaro.org>
Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
---
 .../devicetree/bindings/i2c/i2c-bcm-kona.txt       |  30 +
 drivers/i2c/busses/Kconfig                         |  10 +
 drivers/i2c/busses/Makefile                        |   1 +
 drivers/i2c/busses/i2c-bcm-kona.c                  | 820 +++++++++++++++++++++
 4 files changed, 861 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/i2c/i2c-bcm-kona.txt
 create mode 100644 drivers/i2c/busses/i2c-bcm-kona.c

diff --git a/Documentation/devicetree/bindings/i2c/i2c-bcm-kona.txt b/Documentation/devicetree/bindings/i2c/i2c-bcm-kona.txt
new file mode 100644
index 0000000..fc71a60
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-bcm-kona.txt
@@ -0,0 +1,30 @@
+Broadcom Kona Family I2C
+=========================
+
+This I2C controller is used in the following Broadcom SoCs:
+
+  BCM11130
+  BCM11140
+  BCM11351
+  BCM28145
+  BCM28155
+
+Required Properties
+-------------------
+- compatible: "brcm,bcm11351-i2c", "brcm,kona-i2c"
+- reg: Physical base address and length of controller registers
+- interrupts: The interrupt number used by the controller
+- clock-frequency: The I2C bus frequency in Hz
+- #address-cells: Should be <1>
+- #size-cells: Should be <0>
+
+Example:
+
+i2c@3e016000 {
+	compatible = "brcm,bcm11351-i2c","brcm,kona-i2c";
+	reg = <0x3e016000 0x80>;
+	interrupts = <GIC_SPI 103 IRQ_TYPE_LEVEL_HIGH>;
+	clock-frequency = <400000>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+};
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index cdcbd83..41a3f34 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -963,4 +963,14 @@ config SCx200_ACB
 	  This support is also available as a module.  If so, the module
 	  will be called scx200_acb.
 
+config I2C_BCM_KONA
+	tristate "BCM Kona I2C adapter"
+	depends on ARCH_BCM_MOBILE
+	default y
+	help
+	  If you say yes to this option, support will be included for the
+	  I2C interface on the Broadcom Kona family of processors.
+
+	  If you do not need KONA I2C inteface, say N.
+
 endmenu
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index d00997f..91de826 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -87,6 +87,7 @@ obj-$(CONFIG_I2C_VIPERBOARD)	+= i2c-viperboard.o
 
 # Other I2C/SMBus bus drivers
 obj-$(CONFIG_I2C_ACORN)		+= i2c-acorn.o
+obj-$(CONFIG_I2C_BCM_KONA)	+= i2c-bcm-kona.o
 obj-$(CONFIG_I2C_ELEKTOR)	+= i2c-elektor.o
 obj-$(CONFIG_I2C_PCA_ISA)	+= i2c-pca-isa.o
 obj-$(CONFIG_I2C_SIBYTE)	+= i2c-sibyte.o
diff --git a/drivers/i2c/busses/i2c-bcm-kona.c b/drivers/i2c/busses/i2c-bcm-kona.c
new file mode 100644
index 0000000..2936acf
--- /dev/null
+++ b/drivers/i2c/busses/i2c-bcm-kona.c
@@ -0,0 +1,820 @@
+/*
+ * Copyright (C) 2013 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/slab.h>
+
+/* Hardware register offsets and field defintions */
+#define CS_OFFSET				0x00000020
+#define CS_ACK_SHIFT				3
+#define CS_ACK_MASK				0x00000008
+#define CS_ACK_CMD_GEN_START			0x00000000
+#define CS_ACK_CMD_GEN_RESTART			0x00000001
+#define CS_CMD_SHIFT				1
+#define CS_CMD_CMD_NO_ACTION			0x00000000
+#define CS_CMD_CMD_START_RESTART		0x00000001
+#define CS_CMD_CMD_STOP				0x00000002
+#define CS_EN_SHIFT				0
+#define CS_EN_CMD_ENABLE_BSC			0x00000001
+
+#define TIM_OFFSET				0x00000024
+#define TIM_PRESCALE_SHIFT			6
+#define TIM_P_SHIFT				3
+#define TIM_NO_DIV_SHIFT			2
+#define TIM_DIV_SHIFT				0
+
+#define DAT_OFFSET				0x00000028
+
+#define TOUT_OFFSET				0x0000002c
+
+#define TXFCR_OFFSET				0x0000003c
+#define TXFCR_FIFO_FLUSH_MASK			0x00000080
+#define TXFCR_FIFO_EN_MASK			0x00000040
+
+#define IER_OFFSET				0x00000044
+#define IER_READ_COMPLETE_INT_MASK		0x00000010
+#define IER_I2C_INT_EN_MASK			0x00000008
+#define IER_FIFO_INT_EN_MASK			0x00000002
+#define IER_NOACK_EN_MASK			0x00000001
+
+#define ISR_OFFSET				0x00000048
+#define ISR_RESERVED_MASK			0xffffff60
+#define ISR_CMDBUSY_MASK			0x00000080
+#define ISR_READ_COMPLETE_MASK			0x00000010
+#define ISR_SES_DONE_MASK			0x00000008
+#define ISR_ERR_MASK				0x00000004
+#define ISR_TXFIFOEMPTY_MASK			0x00000002
+#define ISR_NOACK_MASK				0x00000001
+
+#define CLKEN_OFFSET				0x0000004C
+#define CLKEN_AUTOSENSE_OFF_MASK		0x00000080
+#define CLKEN_M_SHIFT				4
+#define CLKEN_N_SHIFT				1
+#define CLKEN_CLKEN_MASK			0x00000001
+
+#define FIFO_STATUS_OFFSET			0x00000054
+#define FIFO_STATUS_RXFIFO_EMPTY_MASK		0x00000004
+#define FIFO_STATUS_TXFIFO_EMPTY_MASK		0x00000010
+
+#define HSTIM_OFFSET				0x00000058
+#define HSTIM_HS_MODE_MASK			0x00008000
+
+#define PADCTL_OFFSET				0x0000005c
+#define PADCTL_PAD_OUT_EN_MASK			0x00000004
+
+#define RXFCR_OFFSET				0x00000068
+#define RXFCR_NACK_EN_SHIFT			7
+#define RXFCR_READ_COUNT_SHIFT			0
+#define RXFIFORDOUT_OFFSET			0x0000006c
+
+/* Locally used constants */
+#define MAX_RX_FIFO_SIZE		64U /* bytes */
+#define MAX_TX_FIFO_SIZE		64U /* bytes */
+
+#define STD_EXT_CLK_FREQ		13000000UL
+
+#define I2C_TIMEOUT			100 /* msecs */
+
+/* Operations that can be commanded to the controller */
+enum bcm_kona_cmd_t {
+	BCM_CMD_NOACTION = 0,
+	BCM_CMD_START,
+	BCM_CMD_RESTART,
+	BCM_CMD_STOP,
+};
+
+enum bus_speed_index {
+	BCM_SPD_100K = 0,
+	BCM_SPD_400K,
+	BCM_SPD_1MHZ,
+};
+
+/* Internal divider settings for standard mode, fast mode and fast mode plus */
+struct bus_speed_cfg {
+	uint8_t time_m;		/* Number of cycles for setup time */
+	uint8_t time_n;		/* Number of cycles for hold time */
+	uint8_t prescale;	/* Prescale divider */
+	uint8_t time_p;		/* Timing coefficient */
+	uint8_t no_div;		/* Disable clock divider */
+	uint8_t time_div;	/* Post-prescale divider */
+};
+
+static const struct bus_speed_cfg std_cfg_table[] = {
+	[BCM_SPD_100K] = {0x01, 0x01, 0x03, 0x06, 0x00, 0x02},
+	[BCM_SPD_400K] = {0x05, 0x01, 0x03, 0x05, 0x01, 0x02},
+	[BCM_SPD_1MHZ] = {0x01, 0x01, 0x03, 0x01, 0x01, 0x03},
+};
+
+struct bcm_kona_i2c_dev {
+	/* Pointer to linux device struct */
+	struct device *device;
+
+	/* Virtual address where registers are mapped */
+	void __iomem *base;
+
+	/* Interrupt */
+	int irq;
+
+	/* Standard Speed configuration */
+	const struct bus_speed_cfg *std_cfg;
+
+	/* Linux I2C adapter struct */
+	struct i2c_adapter adapter;
+
+	/* Lock for the I2C device */
+	struct mutex i2c_bcm_lock;
+
+	/* Completion to signal an operation finished */
+	struct completion done;
+
+	/* Handle for external clock */
+	struct clk *external_clk;
+};
+
+static void bcm_kona_i2c_send_cmd_to_ctrl(struct bcm_kona_i2c_dev *dev,
+					  enum bcm_kona_cmd_t cmd)
+{
+	dev_dbg(dev->device, "%s, %d\n", __func__, cmd);
+
+	switch (cmd) {
+	case BCM_CMD_NOACTION:
+		writel((CS_CMD_CMD_NO_ACTION << CS_CMD_SHIFT) |
+		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+		       dev->base + CS_OFFSET);
+		break;
+
+	case BCM_CMD_START:
+		writel((CS_ACK_CMD_GEN_START << CS_ACK_SHIFT) |
+		       (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
+		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+		       dev->base + CS_OFFSET);
+		break;
+
+	case BCM_CMD_RESTART:
+		writel((CS_ACK_CMD_GEN_RESTART << CS_ACK_SHIFT) |
+		       (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
+		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+		       dev->base + CS_OFFSET);
+		break;
+
+	case BCM_CMD_STOP:
+		writel((CS_CMD_CMD_STOP << CS_CMD_SHIFT) |
+		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+		       dev->base + CS_OFFSET);
+		break;
+
+	default:
+		dev_err(dev->device, "Unknown command %d\n", cmd);
+	}
+}
+
+static void bcm_kona_i2c_enable_clock(struct bcm_kona_i2c_dev *dev)
+{
+	writel(readl(dev->base + CLKEN_OFFSET) | CLKEN_CLKEN_MASK,
+	       dev->base + CLKEN_OFFSET);
+}
+
+static void bcm_kona_i2c_disable_clock(struct bcm_kona_i2c_dev *dev)
+{
+	writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_CLKEN_MASK,
+	       dev->base + CLKEN_OFFSET);
+}
+
+static irqreturn_t bcm_kona_i2c_isr(int irq, void *devid)
+{
+	struct bcm_kona_i2c_dev *dev = devid;
+	uint32_t status = readl(dev->base + ISR_OFFSET);
+
+	if ((status & ~ISR_RESERVED_MASK) == 0)
+		return IRQ_NONE;
+
+	/* Must flush the TX FIFO when NAK detected */
+	if (status & ISR_NOACK_MASK)
+		writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
+		       dev->base + TXFCR_OFFSET);
+
+	writel(status & ~ISR_RESERVED_MASK, dev->base + ISR_OFFSET);
+	complete_all(&dev->done);
+
+	return IRQ_HANDLED;
+}
+
+/* Wait for ISR_CMDBUSY_MASK to go low before writing to CS, DAT, or RCD */
+static int bcm_kona_i2c_wait_if_busy(struct bcm_kona_i2c_dev *dev)
+{
+	unsigned long timeout = jiffies + msecs_to_jiffies(I2C_TIMEOUT);
+
+	while (readl(dev->base + ISR_OFFSET) & ISR_CMDBUSY_MASK)
+		if (time_after(jiffies, timeout)) {
+			dev_err(dev->device, "CMDBUSY timeout\n");
+			return -ETIMEDOUT;
+		}
+
+	return 0;
+}
+
+/* Send command to I2C bus */
+static int bcm_kona_send_i2c_cmd(struct bcm_kona_i2c_dev *dev,
+				 enum bcm_kona_cmd_t cmd)
+{
+	int rc;
+	unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT);
+
+	/* Make sure the hardware is ready */
+	rc = bcm_kona_i2c_wait_if_busy(dev);
+	if (rc < 0)
+		return rc;
+
+	/* Unmask the session done interrupt */
+	writel(IER_I2C_INT_EN_MASK, dev->base + IER_OFFSET);
+
+	/* Mark as incomplete before sending the command */
+	INIT_COMPLETION(dev->done);
+
+	/* Send the command */
+	bcm_kona_i2c_send_cmd_to_ctrl(dev, cmd);
+
+	/* Wait for transaction to finish or timeout */
+	time_left = wait_for_completion_timeout(&dev->done, time_left);
+
+	/* Mask all interrupts */
+	writel(0, dev->base + IER_OFFSET);
+
+	if (!time_left) {
+		dev_err(dev->device, "controller timed out\n");
+		rc = -ETIMEDOUT;
+	}
+
+	/* Clear command */
+	bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
+
+	return rc;
+}
+
+/* Read a single RX FIFO worth of data from the i2c bus */
+static int bcm_kona_i2c_read_fifo_single(struct bcm_kona_i2c_dev *dev,
+					 uint8_t *buf, unsigned int len,
+					 unsigned int last_byte_nak)
+{
+	unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT);
+
+	/* Mark as incomplete before starting the RX FIFO */
+	INIT_COMPLETION(dev->done);
+
+	/* Unmask the read complete interrupt */
+	writel(IER_READ_COMPLETE_INT_MASK, dev->base + IER_OFFSET);
+
+	/* Start the RX FIFO */
+	writel((last_byte_nak << RXFCR_NACK_EN_SHIFT) |
+	       (len << RXFCR_READ_COUNT_SHIFT),
+		dev->base + RXFCR_OFFSET);
+
+	/* Wait for FIFO read to complete */
+	time_left = wait_for_completion_timeout(&dev->done, time_left);
+
+	/* Mask all interrupts */
+	writel(0, dev->base + IER_OFFSET);
+
+	if (!time_left) {
+		dev_err(dev->device, "RX FIFO time out\n");
+		return -EREMOTEIO;
+	}
+
+	/* Read data from FIFO */
+	for (; len > 0; len--, buf++)
+		*buf = readl(dev->base + RXFIFORDOUT_OFFSET);
+
+	return 0;
+}
+
+/* Read any amount of data using the RX FIFO from the i2c bus */
+static int bcm_kona_i2c_read_fifo(struct bcm_kona_i2c_dev *dev,
+				  struct i2c_msg *msg)
+{
+	unsigned int bytes_to_read = MAX_RX_FIFO_SIZE;
+	unsigned int last_byte_nak = 0;
+	unsigned int bytes_read = 0;
+	unsigned int rc;
+
+	uint8_t *tmp_buf = msg->buf;
+
+	while (bytes_read < msg->len) {
+		if (msg->len - bytes_read <= MAX_RX_FIFO_SIZE) {
+			last_byte_nak = 1; /* NAK last byte of transfer */
+			bytes_to_read = msg->len - bytes_read;
+		}
+
+		rc = bcm_kona_i2c_read_fifo_single(dev, tmp_buf, bytes_to_read,
+						   last_byte_nak);
+		if (rc < 0)
+			return -EREMOTEIO;
+
+		bytes_read += bytes_to_read;
+		tmp_buf += bytes_to_read;
+	}
+
+	return 0;
+}
+
+/* Write a single byte of data to the i2c bus */
+static int bcm_kona_i2c_write_byte(struct bcm_kona_i2c_dev *dev, uint8_t data,
+				   unsigned int nak_expected)
+{
+	int rc;
+	unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT);
+	unsigned int nak_received;
+
+	/* Make sure the hardware is ready */
+	rc = bcm_kona_i2c_wait_if_busy(dev);
+	if (rc < 0)
+		return rc;
+
+	/* Clear pending session done interrupt */
+	writel(ISR_SES_DONE_MASK, dev->base + ISR_OFFSET);
+
+	/* Unmask the session done interrupt */
+	writel(IER_I2C_INT_EN_MASK, dev->base + IER_OFFSET);
+
+	/* Mark as incomplete before sending the data */
+	INIT_COMPLETION(dev->done);
+
+	/* Send one byte of data */
+	writel(data, dev->base + DAT_OFFSET);
+
+	/* Wait for byte to be written */
+	time_left = wait_for_completion_timeout(&dev->done, time_left);
+
+	/* Mask all interrupts */
+	writel(0, dev->base + IER_OFFSET);
+
+	if (!time_left) {
+		dev_dbg(dev->device, "controller timed out\n");
+		return -ETIMEDOUT;
+	}
+
+	nak_received = readl(dev->base + CS_OFFSET) & CS_ACK_MASK ? 1 : 0;
+
+	if (nak_received ^ nak_expected) {
+		dev_dbg(dev->device, "unexpected NAK/ACK\n");
+		return -EREMOTEIO;
+	}
+
+	return 0;
+}
+
+/* Write a single TX FIFO worth of data to the i2c bus */
+static int bcm_kona_i2c_write_fifo_single(struct bcm_kona_i2c_dev *dev,
+					  uint8_t *buf, unsigned int len)
+{
+	int k;
+	unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT);
+	unsigned int fifo_status;
+
+	/* Mark as incomplete before sending data to the TX FIFO */
+	INIT_COMPLETION(dev->done);
+
+	/* Unmask the fifo empty and nak interrupt */
+	writel(IER_FIFO_INT_EN_MASK | IER_NOACK_EN_MASK,
+	       dev->base + IER_OFFSET);
+
+	/* Disable IRQ to load a FIFO worth of data without interruption */
+	disable_irq(dev->irq);
+
+	/* Write data into FIFO */
+	for (k = 0; k < len; k++)
+		writel(buf[k], (dev->base + DAT_OFFSET));
+
+	/* Enable IRQ now that data has been loaded */
+	enable_irq(dev->irq);
+
+	/* Wait for FIFO to empty */
+	do {
+		time_left = wait_for_completion_timeout(&dev->done, time_left);
+		fifo_status = readl(dev->base + FIFO_STATUS_OFFSET);
+	} while (time_left && !(fifo_status & FIFO_STATUS_TXFIFO_EMPTY_MASK));
+
+	/* Mask all interrupts */
+	writel(0, dev->base + IER_OFFSET);
+
+	/* Check if there was a NAK */
+	if (readl(dev->base + CS_OFFSET) & CS_ACK_MASK) {
+		dev_err(dev->device, "unexpected NAK\n");
+		return -EREMOTEIO;
+	}
+
+	/* Check if a timeout occured */
+	if (!time_left) {
+		dev_err(dev->device, "completion timed out\n");
+		return -EREMOTEIO;
+	}
+
+	return 0;
+}
+
+
+/* Write any amount of data using TX FIFO to the i2c bus */
+static int bcm_kona_i2c_write_fifo(struct bcm_kona_i2c_dev *dev,
+				   struct i2c_msg *msg)
+{
+	unsigned int bytes_to_write = MAX_TX_FIFO_SIZE;
+	unsigned int bytes_written = 0;
+	unsigned int rc;
+
+	uint8_t *tmp_buf = msg->buf;
+
+	while (bytes_written < msg->len) {
+		if (msg->len - bytes_written <= MAX_TX_FIFO_SIZE)
+			bytes_to_write = msg->len - bytes_written;
+
+		rc = bcm_kona_i2c_write_fifo_single(dev, tmp_buf,
+						    bytes_to_write);
+		if (rc < 0)
+			return -EREMOTEIO;
+
+		bytes_written += bytes_to_write;
+		tmp_buf += bytes_to_write;
+	}
+
+	return 0;
+}
+
+/* Send i2c address */
+static int bcm_kona_i2c_do_addr(struct bcm_kona_i2c_dev *dev,
+				     struct i2c_msg *msg)
+{
+	unsigned char addr;
+
+	if (msg->flags & I2C_M_TEN) {
+		/* First byte is 11110XX0 where XX is upper 2 bits */
+		addr = 0xF0 | ((msg->addr & 0x300) >> 7);
+		if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+			return -EREMOTEIO;
+
+		/* Second byte is the remaining 8 bits */
+		addr = msg->addr & 0xFF;
+		if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+			return -EREMOTEIO;
+
+		if (msg->flags & I2C_M_RD) {
+			/* For read, send restart command */
+			if (bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART) < 0)
+				return -EREMOTEIO;
+
+			/* Then re-send the first byte with the read bit set */
+			addr = 0xF0 | ((msg->addr & 0x300) >> 7) | 0x01;
+			if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+				return -EREMOTEIO;
+		}
+	} else {
+		addr = msg->addr << 1;
+
+		if (msg->flags & I2C_M_RD)
+			addr |= 1;
+
+		if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+			return -EREMOTEIO;
+	}
+
+	return 0;
+}
+
+static void bcm_kona_i2c_enable_autosense(struct bcm_kona_i2c_dev *dev)
+{
+	writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_AUTOSENSE_OFF_MASK,
+	       dev->base + CLKEN_OFFSET);
+}
+
+static void bcm_kona_i2c_config_timing(struct bcm_kona_i2c_dev *dev)
+{
+	writel(readl(dev->base + HSTIM_OFFSET) & ~HSTIM_HS_MODE_MASK,
+	       dev->base + HSTIM_OFFSET);
+
+	writel((dev->std_cfg->prescale << TIM_PRESCALE_SHIFT) |
+	       (dev->std_cfg->time_p << TIM_P_SHIFT) |
+	       (dev->std_cfg->no_div << TIM_NO_DIV_SHIFT) |
+	       (dev->std_cfg->time_div	<< TIM_DIV_SHIFT),
+	       dev->base + TIM_OFFSET);
+
+	writel((dev->std_cfg->time_m << CLKEN_M_SHIFT) |
+	       (dev->std_cfg->time_n << CLKEN_N_SHIFT) |
+	       CLKEN_CLKEN_MASK,
+	       dev->base + CLKEN_OFFSET);
+}
+
+/* Master transfer function */
+static int bcm_kona_i2c_xfer(struct i2c_adapter *adapter,
+			     struct i2c_msg msgs[], int num)
+{
+	struct bcm_kona_i2c_dev *dev = i2c_get_adapdata(adapter);
+	struct i2c_msg *pmsg;
+	int rc = 0;
+	int i;
+
+	mutex_lock(&dev->i2c_bcm_lock);
+
+	rc = clk_prepare_enable(dev->external_clk);
+	if (rc) {
+		dev_err(dev->device, "%s: peri clock enable failed. err %d\n",
+			__func__, rc);
+		goto xfer_mutex_unlock;
+	}
+
+	/* Enable pad output */
+	writel(0, dev->base + PADCTL_OFFSET);
+
+	/* Enable internal clocks */
+	bcm_kona_i2c_enable_clock(dev);
+
+	/* Send start command */
+	rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_START);
+	if (rc < 0) {
+		dev_err(dev->device, "Start command failed rc = %d\n", rc);
+		goto xfer_disable_pad;
+	}
+
+	/* Loop through all messages */
+	for (i = 0; i < num; i++) {
+		pmsg = &msgs[i];
+
+		/* Send restart for subsequent messages */
+		if ((i != 0) && ((pmsg->flags & I2C_M_NOSTART) == 0)) {
+			rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART);
+			if (rc < 0) {
+				dev_err(dev->device,
+					"restart cmd failed rc = %d\n", rc);
+					goto xfer_send_stop;
+			}
+		}
+
+		/* Send slave address */
+		if (!(pmsg->flags & I2C_M_NOSTART)) {
+			rc = bcm_kona_i2c_do_addr(dev, pmsg);
+			if (rc < 0) {
+				dev_err(dev->device,
+					"NAK from addr %2.2x msg#%d rc = %d\n",
+					pmsg->addr, i, rc);
+				goto xfer_send_stop;
+			}
+		}
+
+		/* Perform data transfer */
+		if (pmsg->flags & I2C_M_RD) {
+			rc = bcm_kona_i2c_read_fifo(dev, pmsg);
+			if (rc < 0) {
+				dev_err(dev->device, "read failure\n");
+				goto xfer_send_stop;
+			}
+		} else {
+			rc = bcm_kona_i2c_write_fifo(dev, pmsg);
+			if (rc < 0) {
+				dev_err(dev->device, "write failure");
+				goto xfer_send_stop;
+			}
+		}
+	}
+
+	rc = num;
+
+xfer_send_stop:
+	/* Send a STOP command */
+	bcm_kona_send_i2c_cmd(dev, BCM_CMD_STOP);
+
+xfer_disable_pad:
+	/* Disable pad output */
+	writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
+
+	/* Stop internal clock */
+	bcm_kona_i2c_disable_clock(dev);
+
+	clk_disable_unprepare(dev->external_clk);
+
+xfer_mutex_unlock:
+	mutex_unlock(&dev->i2c_bcm_lock);
+	return rc;
+}
+
+static uint32_t bcm_kona_i2c_functionality(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
+}
+
+static const struct i2c_algorithm bcm_algo = {
+	.master_xfer = bcm_kona_i2c_xfer,
+	.functionality = bcm_kona_i2c_functionality,
+};
+
+static int bcm_kona_i2c_assign_bus_speed(struct bcm_kona_i2c_dev *dev)
+{
+	unsigned int bus_speed;
+	int ret = of_property_read_u32(dev->device->of_node, "clock-frequency",
+				       &bus_speed);
+	if (ret < 0) {
+		dev_err(dev->device, "missing clock-frequency property\n");
+		return -ENODEV;
+	}
+
+	switch (bus_speed) {
+	case 100000:
+		dev->std_cfg = &std_cfg_table[BCM_SPD_100K];
+		break;
+	case 400000:
+		dev->std_cfg = &std_cfg_table[BCM_SPD_400K];
+		break;
+	case 1000000:
+		dev->std_cfg = &std_cfg_table[BCM_SPD_1MHZ];
+		break;
+	default:
+		pr_err("%d hz bus speed not supported\n", bus_speed);
+		return -EINVAL;
+	};
+
+	return 0;
+}
+
+static int bcm_kona_i2c_probe(struct platform_device *pdev)
+{
+	int rc = 0;
+	struct bcm_kona_i2c_dev *dev;
+	struct i2c_adapter *adap;
+	struct resource *iomem;
+
+	/* Allocate memory for private data structure */
+	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
+	if (!dev) {
+		rc = -ENOMEM;
+		goto probe_return;
+	}
+
+	platform_set_drvdata(pdev, dev);
+	dev->device = &pdev->dev;
+	mutex_init(&dev->i2c_bcm_lock);
+	init_completion(&dev->done);
+
+	/* Map hardware registers */
+	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	dev->base = devm_ioremap_resource(dev->device, iomem);
+	if (IS_ERR(dev->base)) {
+		rc = PTR_ERR(dev->base);
+		goto probe_return;
+	}
+
+	/* Get and enable external clock */
+	dev->external_clk = devm_clk_get(dev->device, NULL);
+	if (IS_ERR(dev->external_clk)) {
+		dev_err(dev->device, "couldn't get clock\n");
+		rc = -ENODEV;
+		goto probe_return;
+	}
+
+	rc = clk_set_rate(dev->external_clk, STD_EXT_CLK_FREQ);
+	if (rc) {
+		dev_err(dev->device, "%s: clk_set_rate returned %d\n",
+			__func__, rc);
+		goto probe_return;
+	}
+
+	rc = clk_prepare_enable(dev->external_clk);
+	if (rc) {
+		dev_err(dev->device, "couldn't enable clock\n");
+		goto probe_return;
+	}
+
+	/* Parse bus speed */
+	if (bcm_kona_i2c_assign_bus_speed(dev))
+		goto probe_disable_clk;
+
+	/* Enable internal clocks */
+	bcm_kona_i2c_enable_clock(dev);
+
+	/* Configure internal dividers */
+	bcm_kona_i2c_config_timing(dev);
+
+	/* Disable timeout */
+	writel(0, dev->base + TOUT_OFFSET);
+
+	/* Enable autosense */
+	bcm_kona_i2c_enable_autosense(dev);
+
+	/* Enable TX FIFO */
+	writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
+	       dev->base + TXFCR_OFFSET);
+
+	/* Mask all interrupts */
+	writel(0, dev->base + IER_OFFSET);
+
+	/* Clear all pending interrupts */
+	writel(ISR_CMDBUSY_MASK |
+	       ISR_READ_COMPLETE_MASK |
+	       ISR_SES_DONE_MASK |
+	       ISR_ERR_MASK |
+	       ISR_TXFIFOEMPTY_MASK |
+	       ISR_NOACK_MASK,
+	       dev->base + ISR_OFFSET);
+
+	/* Get the interrupt number */
+	dev->irq = platform_get_irq(pdev, 0);
+	if (dev->irq < 0) {
+		dev_err(dev->device, "no irq resource\n");
+		rc = -ENODEV;
+		goto probe_disable_clk;
+	}
+
+	/* register the ISR handler */
+	rc = devm_request_irq(&pdev->dev, dev->irq, bcm_kona_i2c_isr,
+			      IRQF_SHARED, pdev->name, dev);
+	if (rc) {
+		dev_err(dev->device, "failed to request irq %i\n", dev->irq);
+		goto probe_disable_clk;
+	}
+
+	/* Enable the controller but leave it idle */
+	bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
+
+	/* Disable pad output */
+	writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
+
+	/* Disable internal clock */
+	bcm_kona_i2c_disable_clock(dev);
+
+	/* Disable external clock */
+	clk_disable_unprepare(dev->external_clk);
+
+	/* Add the i2c adapter */
+	adap = &dev->adapter;
+	i2c_set_adapdata(adap, dev);
+	adap->owner = THIS_MODULE;
+	adap->class = UINT_MAX;	/* can be used by any I2C device */
+	strlcpy(adap->name, "Broadcom I2C adapter", sizeof(adap->name));
+	adap->algo = &bcm_algo;
+	adap->dev.parent = &pdev->dev;
+	adap->nr = pdev->id;
+	adap->dev.of_node = pdev->dev.of_node;
+
+	rc = i2c_add_numbered_adapter(adap);
+	if (rc) {
+		dev_err(dev->device, "failed to add adapter\n");
+		goto probe_disable_clk;
+	}
+
+	dev_info(dev->device, "device registered successfully\n");
+
+	return 0;
+
+probe_disable_clk:
+	bcm_kona_i2c_disable_clock(dev);
+	clk_disable_unprepare(dev->external_clk);
+
+probe_return:
+	dev_err(&pdev->dev, "probe failed\n");
+	return rc;
+}
+
+static int bcm_kona_i2c_remove(struct platform_device *pdev)
+{
+	struct bcm_kona_i2c_dev *dev = platform_get_drvdata(pdev);
+
+	i2c_del_adapter(&dev->adapter);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static const struct of_device_id bcm_kona_i2c_of_match[] = {
+	{.compatible = "brcm,kona-i2c",},
+	{},
+};
+MODULE_DEVICE_TABLE(of, kona_i2c_of_match);
+
+static struct platform_driver bcm_kona_i2c_driver = {
+	.driver = {
+		   .name = "bcm-kona-i2c",
+		   .owner = THIS_MODULE,
+		   .of_match_table = bcm_kona_i2c_of_match,
+		   },
+	.probe = bcm_kona_i2c_probe,
+	.remove = bcm_kona_i2c_remove,
+};
+module_platform_driver(bcm_kona_i2c_driver);
+
+MODULE_AUTHOR("Broadcom");
+MODULE_DESCRIPTION("Broadcom Kona I2C Driver");
+MODULE_LICENSE("GPL v2");
-- 
1.8.0.1

Re: [RESEND PATCH 1/4] i2c: i2c-bcm-kona: Introduce Broadcom I2C Driver

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 4334 bytes --]

On Wed, Oct 16, 2013 at 03:01:46PM -0700, Tim Kryger wrote:
> Introduce support for Broadcom Serial Controller (BSC) I2C bus found
> in the Kona family of Mobile SoCs.  FIFO hardware is utilized but only
> standard mode (100kHz), fast mode (400kHz), and fast mode plus (1MHz)
> bus speeds are supported.
> 
> Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
> Reviewed-by: Matt Porter <matt.porter@linaro.org>
> Reviewed-by: Markus Mayer <markus.mayer@linaro.org>

Looks mostly good, some remarks:

> +struct bcm_kona_i2c_dev {
> +	/* Pointer to linux device struct */
> +	struct device *device;
> +
> +	/* Virtual address where registers are mapped */
> +	void __iomem *base;
> +
> +	/* Interrupt */
> +	int irq;
> +
> +	/* Standard Speed configuration */
> +	const struct bus_speed_cfg *std_cfg;
> +
> +	/* Linux I2C adapter struct */
> +	struct i2c_adapter adapter;
> +
> +	/* Lock for the I2C device */
> +	struct mutex i2c_bcm_lock;
> +
> +	/* Completion to signal an operation finished */
> +	struct completion done;
> +
> +	/* Handle for external clock */
> +	struct clk *external_clk;
> +};

IMO most of the comments could go. Kind of stating the obvious :)


> +/* Read any amount of data using the RX FIFO from the i2c bus */
> +static int bcm_kona_i2c_read_fifo(struct bcm_kona_i2c_dev *dev,
> +				  struct i2c_msg *msg)
> +{
> +	unsigned int bytes_to_read = MAX_RX_FIFO_SIZE;
> +	unsigned int last_byte_nak = 0;
> +	unsigned int bytes_read = 0;
> +	unsigned int rc;

Should be signed.

> +/* Write any amount of data using TX FIFO to the i2c bus */
> +static int bcm_kona_i2c_write_fifo(struct bcm_kona_i2c_dev *dev,
> +				   struct i2c_msg *msg)
> +{
> +	unsigned int bytes_to_write = MAX_TX_FIFO_SIZE;
> +	unsigned int bytes_written = 0;
> +	unsigned int rc;

Ditto signed.

> +/* Master transfer function */
> +static int bcm_kona_i2c_xfer(struct i2c_adapter *adapter,
> +			     struct i2c_msg msgs[], int num)
> +{
> +	struct bcm_kona_i2c_dev *dev = i2c_get_adapdata(adapter);
> +	struct i2c_msg *pmsg;
> +	int rc = 0;
> +	int i;
> +
> +	mutex_lock(&dev->i2c_bcm_lock);

Huh? Why do you need that? The core has locks per bus.

> +static int bcm_kona_i2c_assign_bus_speed(struct bcm_kona_i2c_dev *dev)
> +{
> +	unsigned int bus_speed;
> +	int ret = of_property_read_u32(dev->device->of_node, "clock-frequency",
> +				       &bus_speed);
> +	if (ret < 0) {
> +		dev_err(dev->device, "missing clock-frequency property\n");
> +		return -ENODEV;
> +	}
> +
> +	switch (bus_speed) {
> +	case 100000:
> +		dev->std_cfg = &std_cfg_table[BCM_SPD_100K];
> +		break;
> +	case 400000:
> +		dev->std_cfg = &std_cfg_table[BCM_SPD_400K];
> +		break;
> +	case 1000000:
> +		dev->std_cfg = &std_cfg_table[BCM_SPD_1MHZ];
> +		break;
> +	default:
> +		pr_err("%d hz bus speed not supported\n", bus_speed);
> +		return -EINVAL;
> +	};

Unneeded semicolon.

> +
> +	return 0;
> +}
> +
> +static int bcm_kona_i2c_probe(struct platform_device *pdev)
> +{
> +	int rc = 0;
> +	struct bcm_kona_i2c_dev *dev;
> +	struct i2c_adapter *adap;
> +	struct resource *iomem;
> +
> +	/* Allocate memory for private data structure */
> +	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
> +	if (!dev) {
> +		rc = -ENOMEM;
> +		goto probe_return;

I'd prefer simply return -Esomething. The printout at probe_return is
also available via driver core.

...

> +	/* Add the i2c adapter */
> +	adap = &dev->adapter;
> +	i2c_set_adapdata(adap, dev);
> +	adap->owner = THIS_MODULE;
> +	adap->class = UINT_MAX;	/* can be used by any I2C device */

Why do you need class based instantiation. It will most likely cost
boot-time and you have devicetree means for doing instantiation.


> +	strlcpy(adap->name, "Broadcom I2C adapter", sizeof(adap->name));
> +	adap->algo = &bcm_algo;
> +	adap->dev.parent = &pdev->dev;
> +	adap->nr = pdev->id;
> +	adap->dev.of_node = pdev->dev.of_node;
> +
> +	rc = i2c_add_numbered_adapter(adap);

Maybe you want simply i2c_add_adapter here since the core has no
built-in support for of aliases?

> +
> +MODULE_AUTHOR("Broadcom");

Some email address please.

> +MODULE_DESCRIPTION("Broadcom Kona I2C Driver");
> +MODULE_LICENSE("GPL v2");

Thanks,

   Wolfram


[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 836 bytes --]

Re: [RESEND PATCH 1/4] i2c: i2c-bcm-kona: Introduce Broadcom I2C Driver

[Tim Kryger]

On Fri, Nov 1, 2013 at 5:49 AM, Wolfram Sang <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org> wrote:
> On Wed, Oct 16, 2013 at 03:01:46PM -0700, Tim Kryger wrote:
>> Introduce support for Broadcom Serial Controller (BSC) I2C bus found
>> in the Kona family of Mobile SoCs.  FIFO hardware is utilized but only
>> standard mode (100kHz), fast mode (400kHz), and fast mode plus (1MHz)
>> bus speeds are supported.
>>
>> Signed-off-by: Tim Kryger <tim.kryger-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
>> Reviewed-by: Matt Porter <matt.porter-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
>> Reviewed-by: Markus Mayer <markus.mayer-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
>
> Looks mostly good, some remarks:
>
>> +struct bcm_kona_i2c_dev {
>> +     /* Pointer to linux device struct */
>> +     struct device *device;
>> +
>> +     /* Virtual address where registers are mapped */
>> +     void __iomem *base;
>> +
>> +     /* Interrupt */
>> +     int irq;
>> +
>> +     /* Standard Speed configuration */
>> +     const struct bus_speed_cfg *std_cfg;
>> +
>> +     /* Linux I2C adapter struct */
>> +     struct i2c_adapter adapter;
>> +
>> +     /* Lock for the I2C device */
>> +     struct mutex i2c_bcm_lock;
>> +
>> +     /* Completion to signal an operation finished */
>> +     struct completion done;
>> +
>> +     /* Handle for external clock */
>> +     struct clk *external_clk;
>> +};
>
> IMO most of the comments could go. Kind of stating the obvious :)

Sure thing.

>
>> +/* Read any amount of data using the RX FIFO from the i2c bus */
>> +static int bcm_kona_i2c_read_fifo(struct bcm_kona_i2c_dev *dev,
>> +                               struct i2c_msg *msg)
>> +{
>> +     unsigned int bytes_to_read = MAX_RX_FIFO_SIZE;
>> +     unsigned int last_byte_nak = 0;
>> +     unsigned int bytes_read = 0;
>> +     unsigned int rc;
>
> Should be signed.

Absolutely.  Thanks for catching this one.

>
>> +/* Write any amount of data using TX FIFO to the i2c bus */
>> +static int bcm_kona_i2c_write_fifo(struct bcm_kona_i2c_dev *dev,
>> +                                struct i2c_msg *msg)
>> +{
>> +     unsigned int bytes_to_write = MAX_TX_FIFO_SIZE;
>> +     unsigned int bytes_written = 0;
>> +     unsigned int rc;
>
> Ditto signed.

I shall fix it.

>
>> +/* Master transfer function */
>> +static int bcm_kona_i2c_xfer(struct i2c_adapter *adapter,
>> +                          struct i2c_msg msgs[], int num)
>> +{
>> +     struct bcm_kona_i2c_dev *dev = i2c_get_adapdata(adapter);
>> +     struct i2c_msg *pmsg;
>> +     int rc = 0;
>> +     int i;
>> +
>> +     mutex_lock(&dev->i2c_bcm_lock);
>
> Huh? Why do you need that? The core has locks per bus.

In that case, I will remove the local mutex.

>> +static int bcm_kona_i2c_assign_bus_speed(struct bcm_kona_i2c_dev *dev)
>> +{
>> +     unsigned int bus_speed;
>> +     int ret = of_property_read_u32(dev->device->of_node, "clock-frequency",
>> +                                    &bus_speed);
>> +     if (ret < 0) {
>> +             dev_err(dev->device, "missing clock-frequency property\n");
>> +             return -ENODEV;
>> +     }
>> +
>> +     switch (bus_speed) {
>> +     case 100000:
>> +             dev->std_cfg = &std_cfg_table[BCM_SPD_100K];
>> +             break;
>> +     case 400000:
>> +             dev->std_cfg = &std_cfg_table[BCM_SPD_400K];
>> +             break;
>> +     case 1000000:
>> +             dev->std_cfg = &std_cfg_table[BCM_SPD_1MHZ];
>> +             break;
>> +     default:
>> +             pr_err("%d hz bus speed not supported\n", bus_speed);
>> +             return -EINVAL;
>> +     };
>
> Unneeded semicolon.
>

Sure.  It will be removed.

>> +
>> +     return 0;
>> +}
>> +
>> +static int bcm_kona_i2c_probe(struct platform_device *pdev)
>> +{
>> +     int rc = 0;
>> +     struct bcm_kona_i2c_dev *dev;
>> +     struct i2c_adapter *adap;
>> +     struct resource *iomem;
>> +
>> +     /* Allocate memory for private data structure */
>> +     dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
>> +     if (!dev) {
>> +             rc = -ENOMEM;
>> +             goto probe_return;
>
> I'd prefer simply return -Esomething. The printout at probe_return is
> also available via driver core.

Agreed.

> ...
>
>> +     /* Add the i2c adapter */
>> +     adap = &dev->adapter;
>> +     i2c_set_adapdata(adap, dev);
>> +     adap->owner = THIS_MODULE;
>> +     adap->class = UINT_MAX; /* can be used by any I2C device */
>
> Why do you need class based instantiation. It will most likely cost
> boot-time and you have devicetree means for doing instantiation.
>
>

Agreed.

>> +     strlcpy(adap->name, "Broadcom I2C adapter", sizeof(adap->name));
>> +     adap->algo = &bcm_algo;
>> +     adap->dev.parent = &pdev->dev;
>> +     adap->nr = pdev->id;
>> +     adap->dev.of_node = pdev->dev.of_node;
>> +
>> +     rc = i2c_add_numbered_adapter(adap);
>
> Maybe you want simply i2c_add_adapter here since the core has no
> built-in support for of aliases?
>

Okay.  I will switch to i2c_add_adapter and remove the adap->nr assignment.

>> +
>> +MODULE_AUTHOR("Broadcom");
>
> Some email address please.
>
>> +MODULE_DESCRIPTION("Broadcom Kona I2C Driver");
>> +MODULE_LICENSE("GPL v2");
>
> Thanks,
>
>    Wolfram
>

[RESEND PATCH 2/4] i2c: i2c-bcm-kona: Add support for high-speed mode

[Tim Kryger]

Add support for I2C high-speed mode (3.4 MHz).

Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <matt.porter@linaro.org>
Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
---
 drivers/i2c/busses/i2c-bcm-kona.c | 116 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)

diff --git a/drivers/i2c/busses/i2c-bcm-kona.c b/drivers/i2c/busses/i2c-bcm-kona.c
index 2936acf..458714f 100644
--- a/drivers/i2c/busses/i2c-bcm-kona.c
+++ b/drivers/i2c/busses/i2c-bcm-kona.c
@@ -77,6 +77,9 @@
 
 #define HSTIM_OFFSET				0x00000058
 #define HSTIM_HS_MODE_MASK			0x00008000
+#define HSTIM_HS_HOLD_SHIFT			10
+#define HSTIM_HS_HIGH_PHASE_SHIFT		5
+#define HSTIM_HS_SETUP_SHIFT			0
 
 #define PADCTL_OFFSET				0x0000005c
 #define PADCTL_PAD_OUT_EN_MASK			0x00000004
@@ -91,6 +94,9 @@
 #define MAX_TX_FIFO_SIZE		64U /* bytes */
 
 #define STD_EXT_CLK_FREQ		13000000UL
+#define HS_EXT_CLK_FREQ			104000000UL
+
+#define MASTERCODE			0x08 /* Mastercodes are 0000_1xxxb */
 
 #define I2C_TIMEOUT			100 /* msecs */
 
@@ -108,6 +114,10 @@ enum bus_speed_index {
 	BCM_SPD_1MHZ,
 };
 
+enum hs_bus_speed_index {
+	BCM_SPD_3P4MHZ = 0,
+};
+
 /* Internal divider settings for standard mode, fast mode and fast mode plus */
 struct bus_speed_cfg {
 	uint8_t time_m;		/* Number of cycles for setup time */
@@ -118,12 +128,30 @@ struct bus_speed_cfg {
 	uint8_t time_div;	/* Post-prescale divider */
 };
 
+/* Internal divider settings for high-speed mode */
+struct hs_bus_speed_cfg {
+	uint8_t hs_hold;	/* Number of clock cycles SCL stays low until
+				   the end of bit period */
+	uint8_t hs_high_phase;	/* Number of clock cycles SCL stays high
+				   before it falls */
+	uint8_t hs_setup;	/* Number of clock cycles SCL stays low
+				   before it rises  */
+	uint8_t prescale;	/* Prescale divider */
+	uint8_t time_p;		/* Timing coefficient */
+	uint8_t no_div;		/* Disable clock divider */
+	uint8_t time_div;	/* Post-prescale divider */
+};
+
 static const struct bus_speed_cfg std_cfg_table[] = {
 	[BCM_SPD_100K] = {0x01, 0x01, 0x03, 0x06, 0x00, 0x02},
 	[BCM_SPD_400K] = {0x05, 0x01, 0x03, 0x05, 0x01, 0x02},
 	[BCM_SPD_1MHZ] = {0x01, 0x01, 0x03, 0x01, 0x01, 0x03},
 };
 
+static const struct hs_bus_speed_cfg hs_cfg_table[] = {
+	[BCM_SPD_3P4MHZ] = {0x01, 0x08, 0x14, 0x00, 0x06, 0x01, 0x00},
+};
+
 struct bcm_kona_i2c_dev {
 	/* Pointer to linux device struct */
 	struct device *device;
@@ -137,6 +165,9 @@ struct bcm_kona_i2c_dev {
 	/* Standard Speed configuration */
 	const struct bus_speed_cfg *std_cfg;
 
+	/* High Speed configuration (if applicable) */
+	const struct hs_bus_speed_cfg *hs_cfg;
+
 	/* Linux I2C adapter struct */
 	struct i2c_adapter adapter;
 
@@ -520,6 +551,72 @@ static void bcm_kona_i2c_config_timing(struct bcm_kona_i2c_dev *dev)
 	       dev->base + CLKEN_OFFSET);
 }
 
+static void bcm_kona_i2c_config_timing_hs(struct bcm_kona_i2c_dev *dev)
+{
+	writel((dev->hs_cfg->prescale << TIM_PRESCALE_SHIFT) |
+	       (dev->hs_cfg->time_p << TIM_P_SHIFT) |
+	       (dev->hs_cfg->no_div << TIM_NO_DIV_SHIFT) |
+	       (dev->hs_cfg->time_div << TIM_DIV_SHIFT),
+	       dev->base + TIM_OFFSET);
+
+	writel((dev->hs_cfg->hs_hold << HSTIM_HS_HOLD_SHIFT) |
+	       (dev->hs_cfg->hs_high_phase << HSTIM_HS_HIGH_PHASE_SHIFT) |
+	       (dev->hs_cfg->hs_setup << HSTIM_HS_SETUP_SHIFT),
+	       dev->base + HSTIM_OFFSET);
+
+	writel(readl(dev->base + HSTIM_OFFSET) | HSTIM_HS_MODE_MASK,
+	       dev->base + HSTIM_OFFSET);
+}
+
+static int bcm_kona_i2c_switch_to_hs(struct bcm_kona_i2c_dev *dev)
+{
+	int rc;
+
+	/* Send mastercode at standard speed */
+	rc = bcm_kona_i2c_write_byte(dev, MASTERCODE, 1);
+	if (rc < 0) {
+		pr_err("High speed handshake failed\n");
+		return rc;
+	}
+
+	/* Configure external clock to higher frequency */
+	rc = clk_set_rate(dev->external_clk, HS_EXT_CLK_FREQ);
+	if (rc) {
+		dev_err(dev->device, "%s: clk_set_rate returned %d\n",
+			__func__, rc);
+		return rc;
+	}
+
+	/* Reconfigure internal dividers */
+	bcm_kona_i2c_config_timing_hs(dev);
+
+	/* Send a restart command */
+	rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART);
+	if (rc < 0) {
+		dev_err(dev->device,
+		"High speed restart command failed rc = %d\n", rc);
+	}
+
+	return rc;
+}
+
+static int bcm_kona_i2c_switch_to_std(struct bcm_kona_i2c_dev *dev)
+{
+	int rc;
+
+	/* Reconfigure internal dividers */
+	bcm_kona_i2c_config_timing(dev);
+
+	/* Configure external clock to lower frequency */
+	rc = clk_set_rate(dev->external_clk, STD_EXT_CLK_FREQ);
+	if (rc) {
+		dev_err(dev->device, "%s: clk_set_rate returned %d\n",
+			__func__, rc);
+	}
+
+	return rc;
+}
+
 /* Master transfer function */
 static int bcm_kona_i2c_xfer(struct i2c_adapter *adapter,
 			     struct i2c_msg msgs[], int num)
@@ -551,6 +648,13 @@ static int bcm_kona_i2c_xfer(struct i2c_adapter *adapter,
 		goto xfer_disable_pad;
 	}
 
+	/* Switch to high speed if applicable */
+	if (dev->hs_cfg) {
+		rc = bcm_kona_i2c_switch_to_hs(dev);
+		if (rc < 0)
+			goto xfer_send_stop;
+	}
+
 	/* Loop through all messages */
 	for (i = 0; i < num; i++) {
 		pmsg = &msgs[i];
@@ -598,6 +702,13 @@ xfer_send_stop:
 	/* Send a STOP command */
 	bcm_kona_send_i2c_cmd(dev, BCM_CMD_STOP);
 
+	/* Return from high speed if applicable */
+	if (dev->hs_cfg) {
+		int hs_rc = bcm_kona_i2c_switch_to_std(dev);
+		if (hs_rc)
+			rc = hs_rc;
+	}
+
 xfer_disable_pad:
 	/* Disable pad output */
 	writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
@@ -642,6 +753,11 @@ static int bcm_kona_i2c_assign_bus_speed(struct bcm_kona_i2c_dev *dev)
 	case 1000000:
 		dev->std_cfg = &std_cfg_table[BCM_SPD_1MHZ];
 		break;
+	case 3400000:
+		/* Send mastercode at 100k */
+		dev->std_cfg = &std_cfg_table[BCM_SPD_100K];
+		dev->hs_cfg = &hs_cfg_table[BCM_SPD_3P4MHZ];
+		break;
 	default:
 		pr_err("%d hz bus speed not supported\n", bus_speed);
 		return -EINVAL;
-- 
1.8.0.1

Re: [RESEND PATCH 2/4] i2c: i2c-bcm-kona: Add support for high-speed mode

[Wolfram Sang]

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On Wed, Oct 16, 2013 at 03:01:47PM -0700, Tim Kryger wrote:
> Add support for I2C high-speed mode (3.4 MHz).
> 
> Signed-off-by: Tim Kryger <tim.kryger-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> Reviewed-by: Matt Porter <matt.porter-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> Reviewed-by: Markus Mayer <markus.mayer-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>

Mostly good as well:

> +enum hs_bus_speed_index {
> +	BCM_SPD_3P4MHZ = 0,
> +};

I just realized that you should update both patches to add the supported
bus speeds to the binding documentation.

Thanks,

   Wolfram


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Re: [RESEND PATCH 2/4] i2c: i2c-bcm-kona: Add support for high-speed mode

[Tim Kryger]

On Fri, Nov 1, 2013 at 6:08 AM, Wolfram Sang <wsa@the-dreams.de> wrote:
> On Wed, Oct 16, 2013 at 03:01:47PM -0700, Tim Kryger wrote:
>> Add support for I2C high-speed mode (3.4 MHz).
>>
>> Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
>> Reviewed-by: Matt Porter <matt.porter@linaro.org>
>> Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
>
> Mostly good as well:
>
>> +enum hs_bus_speed_index {
>> +     BCM_SPD_3P4MHZ = 0,
>> +};
>
> I just realized that you should update both patches to add the supported
> bus speeds to the binding documentation.

While the bus speed property is really a configuration parameter (and
not a true description of of the hardware) it seems improper to put
driver specific details into the binding document.

Please let me know how you would like me to proceed.

I should mention that I plan to break out the binding into its own
patch as this seems to be the latest best practice just in case that
influences your decision.

Thanks,
Tim Kryger

Re: [RESEND PATCH 2/4] i2c: i2c-bcm-kona: Add support for high-speed mode

[Wolfram Sang]

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> While the bus speed property is really a configuration parameter (and
> not a true description of of the hardware) it seems improper to put
> driver specific details into the binding document.

OK. Then please change the error message for unsupported bus speeds to
contain the supported ones. I don't think it is good practice to force
users to look into the sourcecode to find this information.

Regards,

   Wolfram


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Re: [RESEND PATCH 2/4] i2c: i2c-bcm-kona: Add support for high-speed mode

[Tim Kryger]

On Thu, Nov 7, 2013 at 12:13 PM, Wolfram Sang <wsa@the-dreams.de> wrote:

> OK. Then please change the error message for unsupported bus speeds to
> contain the supported ones. I don't think it is good practice to force
> users to look into the sourcecode to find this information.

That works for me.  Thanks.

-Tim

[RESEND PATCH 3/4] ARM: dts: bcm281xx: Add i2c busses

[Tim Kryger]

Add the DTS nodes for all the i2c busses in the SoC.

Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Christian Daudt <csd@broadcom.com>
Reviewed-by: Matt Porter <matt.porter@linaro.org>
Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
---
 arch/arm/boot/dts/bcm11351.dtsi | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/arch/arm/boot/dts/bcm11351.dtsi b/arch/arm/boot/dts/bcm11351.dtsi
index 1246885..4bfd7e3 100644
--- a/arch/arm/boot/dts/bcm11351.dtsi
+++ b/arch/arm/boot/dts/bcm11351.dtsi
@@ -146,6 +146,46 @@
 		status = "disabled";
 	};
 
+	i2c@3e016000 {
+		compatible = "brcm,bcm11351-i2c", "brcm,kona-i2c";
+		reg = <0x3e016000 0x80>;
+		interrupts = <GIC_SPI 103 IRQ_TYPE_LEVEL_HIGH>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		clocks = <&bsc1_clk>;
+		status = "disabled";
+	};
+
+	i2c@3e017000 {
+		compatible = "brcm,bcm11351-i2c", "brcm,kona-i2c";
+		reg = <0x3e017000 0x80>;
+		interrupts = <GIC_SPI 102 IRQ_TYPE_LEVEL_HIGH>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		clocks = <&bsc2_clk>;
+		status = "disabled";
+	};
+
+	i2c@3e018000 {
+		compatible = "brcm,bcm11351-i2c", "brcm,kona-i2c";
+		reg = <0x3e018000 0x80>;
+		interrupts = <GIC_SPI 169 IRQ_TYPE_LEVEL_HIGH>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		clocks = <&bsc3_clk>;
+		status = "disabled";
+	};
+
+	i2c@3500d000 {
+		compatible = "brcm,bcm11351-i2c", "brcm,kona-i2c";
+		reg = <0x3500d000 0x80>;
+		interrupts = <GIC_SPI 14 IRQ_TYPE_LEVEL_HIGH>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		clocks = <&pmu_bsc_clk>;
+		status = "disabled";
+	};
+
 	clocks {
 		bsc1_clk: bsc1 {
 			compatible = "fixed-clock";
-- 
1.8.0.1

Re: [RESEND PATCH 3/4] ARM: dts: bcm281xx: Add i2c busses

[Christian Daudt]

Hi Tim,
 This patch does not work as it relies on the yet-unmerged clock code
for bcm11351. This patch does not apply to -rc, and when tweaked it
does not compile as it references  non-existent bsc_clks.
 Has the clk patches been submitted yet ? Applying this will have to
wait until those have been accepted.

 thanks,
   csd


On Wed, Oct 16, 2013 at 3:01 PM, Tim Kryger <tim.kryger@linaro.org> wrote:
> Add the DTS nodes for all the i2c busses in the SoC.
>
> Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
> Reviewed-by: Christian Daudt <csd@broadcom.com>
> Reviewed-by: Matt Porter <matt.porter@linaro.org>
> Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
> ---
>  arch/arm/boot/dts/bcm11351.dtsi | 40 ++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 40 insertions(+)
>
> diff --git a/arch/arm/boot/dts/bcm11351.dtsi b/arch/arm/boot/dts/bcm11351.dtsi
> index 1246885..4bfd7e3 100644
> --- a/arch/arm/boot/dts/bcm11351.dtsi
> +++ b/arch/arm/boot/dts/bcm11351.dtsi
> @@ -146,6 +146,46 @@
>                 status = "disabled";
>         };
>
> +       i2c@3e016000 {
> +               compatible = "brcm,bcm11351-i2c", "brcm,kona-i2c";
> +               reg = <0x3e016000 0x80>;
> +               interrupts = <GIC_SPI 103 IRQ_TYPE_LEVEL_HIGH>;
> +               #address-cells = <1>;
> +               #size-cells = <0>;
> +               clocks = <&bsc1_clk>;
> +               status = "disabled";
> +       };
> +
> +       i2c@3e017000 {
> +               compatible = "brcm,bcm11351-i2c", "brcm,kona-i2c";
> +               reg = <0x3e017000 0x80>;
> +               interrupts = <GIC_SPI 102 IRQ_TYPE_LEVEL_HIGH>;
> +               #address-cells = <1>;
> +               #size-cells = <0>;
> +               clocks = <&bsc2_clk>;
> +               status = "disabled";
> +       };
> +
> +       i2c@3e018000 {
> +               compatible = "brcm,bcm11351-i2c", "brcm,kona-i2c";
> +               reg = <0x3e018000 0x80>;
> +               interrupts = <GIC_SPI 169 IRQ_TYPE_LEVEL_HIGH>;
> +               #address-cells = <1>;
> +               #size-cells = <0>;
> +               clocks = <&bsc3_clk>;
> +               status = "disabled";
> +       };
> +
> +       i2c@3500d000 {
> +               compatible = "brcm,bcm11351-i2c", "brcm,kona-i2c";
> +               reg = <0x3500d000 0x80>;
> +               interrupts = <GIC_SPI 14 IRQ_TYPE_LEVEL_HIGH>;
> +               #address-cells = <1>;
> +               #size-cells = <0>;
> +               clocks = <&pmu_bsc_clk>;
> +               status = "disabled";
> +       };
> +
>         clocks {
>                 bsc1_clk: bsc1 {
>                         compatible = "fixed-clock";
> --
> 1.8.0.1
>
>

Re: [RESEND PATCH 3/4] ARM: dts: bcm281xx: Add i2c busses

[Matt Porter]

On Wed, Oct 16, 2013 at 09:32:51PM -0700, Christian Daudt wrote:
> Hi Tim,
>  This patch does not work as it relies on the yet-unmerged clock code
> for bcm11351. This patch does not apply to -rc, and when tweaked it
> does not compile as it references  non-existent bsc_clks.
>  Has the clk patches been submitted yet ? Applying this will have to
> wait until those have been accepted.

Hi Christian, Tim mentioned the dependencies in the cover letter.
Sebastian's series, for which the pull request is already sent, and then
Tim's own fixed clock series that is pending some review.

-Matt

> On Wed, Oct 16, 2013 at 3:01 PM, Tim Kryger <tim.kryger@linaro.org> wrote:
> > Add the DTS nodes for all the i2c busses in the SoC.
> >
> > Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
> > Reviewed-by: Christian Daudt <csd@broadcom.com>
> > Reviewed-by: Matt Porter <matt.porter@linaro.org>
> > Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
> > ---
> >  arch/arm/boot/dts/bcm11351.dtsi | 40 ++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 40 insertions(+)
> >
> > diff --git a/arch/arm/boot/dts/bcm11351.dtsi b/arch/arm/boot/dts/bcm11351.dtsi
> > index 1246885..4bfd7e3 100644
> > --- a/arch/arm/boot/dts/bcm11351.dtsi
> > +++ b/arch/arm/boot/dts/bcm11351.dtsi
> > @@ -146,6 +146,46 @@
> >                 status = "disabled";
> >         };
> >
> > +       i2c@3e016000 {
> > +               compatible = "brcm,bcm11351-i2c", "brcm,kona-i2c";
> > +               reg = <0x3e016000 0x80>;
> > +               interrupts = <GIC_SPI 103 IRQ_TYPE_LEVEL_HIGH>;
> > +               #address-cells = <1>;
> > +               #size-cells = <0>;
> > +               clocks = <&bsc1_clk>;
> > +               status = "disabled";
> > +       };
> > +
> > +       i2c@3e017000 {
> > +               compatible = "brcm,bcm11351-i2c", "brcm,kona-i2c";
> > +               reg = <0x3e017000 0x80>;
> > +               interrupts = <GIC_SPI 102 IRQ_TYPE_LEVEL_HIGH>;
> > +               #address-cells = <1>;
> > +               #size-cells = <0>;
> > +               clocks = <&bsc2_clk>;
> > +               status = "disabled";
> > +       };
> > +
> > +       i2c@3e018000 {
> > +               compatible = "brcm,bcm11351-i2c", "brcm,kona-i2c";
> > +               reg = <0x3e018000 0x80>;
> > +               interrupts = <GIC_SPI 169 IRQ_TYPE_LEVEL_HIGH>;
> > +               #address-cells = <1>;
> > +               #size-cells = <0>;
> > +               clocks = <&bsc3_clk>;
> > +               status = "disabled";
> > +       };
> > +
> > +       i2c@3500d000 {
> > +               compatible = "brcm,bcm11351-i2c", "brcm,kona-i2c";
> > +               reg = <0x3500d000 0x80>;
> > +               interrupts = <GIC_SPI 14 IRQ_TYPE_LEVEL_HIGH>;
> > +               #address-cells = <1>;
> > +               #size-cells = <0>;
> > +               clocks = <&pmu_bsc_clk>;
> > +               status = "disabled";
> > +       };
> > +
> >         clocks {
> >                 bsc1_clk: bsc1 {
> >                         compatible = "fixed-clock";
> > --
> > 1.8.0.1
> >
> >
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[RESEND PATCH 4/4] ARM: dts: bcm28155-ap: Enable all the i2c busses

[Tim Kryger]

Enable all available i2c busses.

Signed-off-by: Tim Kryger <tim.kryger-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Reviewed-by: Christian Daudt <csd-dY08KVG/lbpWk0Htik3J/w@public.gmane.org>
Reviewed-by: Matt Porter <matt.porter-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Reviewed-by: Markus Mayer <markus.mayer-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
 arch/arm/boot/dts/bcm28155-ap.dts | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/arm/boot/dts/bcm28155-ap.dts b/arch/arm/boot/dts/bcm28155-ap.dts
index 08e47c2..bab302d 100644
--- a/arch/arm/boot/dts/bcm28155-ap.dts
+++ b/arch/arm/boot/dts/bcm28155-ap.dts
@@ -27,6 +27,26 @@
 		status = "okay";
 	};
 
+	i2c@3e016000 {
+		status="okay";
+		clock-frequency = <400000>;
+	};
+
+	i2c@3e017000 {
+		status="okay";
+		clock-frequency = <400000>;
+	};
+
+	i2c@3e018000 {
+		status="okay";
+		clock-frequency = <400000>;
+	};
+
+	i2c@3500d000 {
+		status="okay";
+		clock-frequency = <400000>;
+	};
+
 	sdio1: sdio@3f180000 {
 		max-frequency = <48000000>;
 		status = "okay";
-- 
1.8.0.1


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