new file mode 100644
@@ -0,0 +1,24 @@
+* Wondermedia I2C Controller
+
+Required properties :
+
+ - compatible : should be "wm,wm8505-i2c"
+ - reg : Offset and length of the register set for the device
+ - interrupts : <IRQ> where IRQ is the interrupt number
+ - clocks : phandle to the I2C clock source
+
+Optional properties :
+
+ - clock-frequency : desired I2C bus clock frequency in Hz.
+ Valid values are 100000 and 400000.
+ Default to 100000 if not specified, or invalid value.
+
+Example :
+
+ i2c_0: i2c@d8280000 {
+ compatible = "wm,wm8505-i2c";
+ reg = <0xd8280000 0x1000>;
+ interrupts = <19>;
+ clocks = <&clki2c0>;
+ clock-frequency = <400000>;
+ };
@@ -700,6 +700,13 @@ config I2C_VERSATILE
This driver can also be built as a module. If so, the module
will be called i2c-versatile.
+config I2C_WMT
+ tristate "Wondermedia I2C Controller support"
+ depends on ARCH_VT8500
+ help
+ If you say yes to this option, support will be included for the
+ I2C controllers found in Wondermedia SoCs.
+
config I2C_OCTEON
tristate "Cavium OCTEON I2C bus support"
depends on CPU_CAVIUM_OCTEON
@@ -69,6 +69,7 @@ obj-$(CONFIG_I2C_SIRF) += i2c-sirf.o
obj-$(CONFIG_I2C_STU300) += i2c-stu300.o
obj-$(CONFIG_I2C_TEGRA) += i2c-tegra.o
obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o
+obj-$(CONFIG_I2C_WMT) += i2c-wmt.o
obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o
obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o
obj-$(CONFIG_I2C_XLR) += i2c-xlr.o
new file mode 100644
@@ -0,0 +1,636 @@
+/*
+ * Wondermedia I2C Master Mode Driver
+ *
+ * Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
+ *
+ * Derived from GPL licensed source:
+ * - Copyright (C) 2008 WonderMedia Technologies, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_i2c.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+
+#define REG_CR 0x00
+#define REG_TCR 0x02
+#define REG_CSR 0x04
+#define REG_ISR 0x06
+#define REG_IMR 0x08
+#define REG_CDR 0x0A
+#define REG_TR 0x0C
+#define REG_MCR 0x0E
+#define REG_SLAVE_CR 0x10
+#define REG_SLAVE_SR 0x12
+#define REG_SLAVE_ISR 0x14
+#define REG_SLAVE_IMR 0x16
+#define REG_SLAVE_DR 0x18
+#define REG_SLAVE_TR 0x1A
+
+/* REG_CR Bit fields */
+#define CR_TX_NEXT_ACK 0x0000
+#define CR_ENABLE 0x0001
+#define CR_TX_NEXT_NO_ACK 0x0002
+#define CR_TX_END 0x0004
+#define CR_CPU_RDY 0x0008
+#define SLAV_MODE_SEL 0x8000
+
+/* REG_TCR Bit fields */
+#define TCR_STANDARD_MODE 0x0000
+#define TCR_MASTER_WRITE 0x0000
+#define TCR_HS_MODE 0x2000
+#define TCR_MASTER_READ 0x4000
+#define TCR_FAST_MODE 0x8000
+#define TCR_SLAVE_ADDR_MASK 0x007F
+
+/* REG_ISR Bit fields */
+#define ISR_NACK_ADDR 0x0001
+#define ISR_BYTE_END 0x0002
+#define ISR_SCL_TIMEOUT 0x0004
+#define ISR_WRITE_ALL 0x0007
+
+/* REG_IMR Bit fields */
+#define IMR_ENABLE_ALL 0x0007
+
+/* REG_CSR Bit fields */
+#define CSR_RCV_NOT_ACK 0x0001
+#define CSR_RCV_ACK_MASK 0x0001
+#define CSR_READY_MASK 0x0002
+
+#define I2C_MODE_STANDARD 0
+#define I2C_MODE_FAST 1
+
+
+
+struct wmt_i2c_dev {
+ struct i2c_adapter adapter;
+ struct completion complete;
+ struct device *dev;
+ void __iomem *base;
+ struct clk *clk;
+ int mode;
+ int irq;
+ u16 cmd_status;
+};
+
+static int wmt_i2c_wait_bus_not_busy(struct wmt_i2c_dev *i2c_dev)
+{
+ u16 val;
+ int i;
+ int ret = 0;
+
+ for (i = 0; i < 10000000; i++) {
+ val = readw(i2c_dev->base + REG_CSR);
+ if (val & CSR_READY_MASK)
+ break;
+
+ udelay(1);
+ }
+ if (i >= 9999999)
+ ret = -EBUSY;
+
+ return ret;
+}
+
+static int wmt_check_status(struct wmt_i2c_dev *i2c_dev)
+{
+ int ret = 0;
+
+ if (i2c_dev->cmd_status & ISR_NACK_ADDR)
+ ret = -EIO;
+
+ if (i2c_dev->cmd_status & ISR_SCL_TIMEOUT)
+ ret = -ETIMEDOUT;
+
+ return ret;
+}
+
+static int wmt_i2c_write(struct i2c_adapter *adap, struct i2c_msg *pmsg,
+ int restart, int last)
+{
+ struct wmt_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
+ u16 val;
+ u16 tcr_val;
+ int ret;
+ int wait_result;
+ u32 xfer_len = 0;
+
+ if (pmsg->len < 0)
+ return -EINVAL;
+
+ if (restart == 0) {
+ ret = wmt_i2c_wait_bus_not_busy(i2c_dev);
+ if (ret < 0)
+ return ret;
+ }
+
+ if (pmsg->len == 0)
+ writew(0, i2c_dev->base + REG_CDR);
+ else
+ writew(pmsg->buf[0] & 0xFF, i2c_dev->base + REG_CDR);
+
+ if (restart == 0) {
+ val = readw(i2c_dev->base + REG_CR);
+ val &= ~CR_TX_END;
+ writew(val, i2c_dev->base + REG_CR);
+
+ val = readw(i2c_dev->base + REG_CR);
+ val |= CR_CPU_RDY;
+ writew(val, i2c_dev->base + REG_CR);
+ }
+
+ init_completion(&i2c_dev->complete);
+
+ if (i2c_dev->mode == I2C_MODE_STANDARD)
+ tcr_val = TCR_STANDARD_MODE;
+ else
+ tcr_val = TCR_FAST_MODE;
+
+ tcr_val |= (TCR_MASTER_WRITE | (pmsg->addr & TCR_SLAVE_ADDR_MASK));
+
+ writew(tcr_val, i2c_dev->base + REG_TCR);
+
+ if (restart == 1) {
+ val = readw(i2c_dev->base + REG_CR);
+ val |= CR_CPU_RDY;
+ writew(val, i2c_dev->base + REG_CR);
+ }
+
+ ret = 0;
+
+ for (;;) {
+ wait_result = wait_for_completion_interruptible_timeout(
+ &i2c_dev->complete, 500 * HZ / 1000);
+
+ if (wait_result == 0) {
+ dev_dbg(i2c_dev->dev, "wait timeout (tx)\n");
+ ret = -ETIMEDOUT;
+ break;
+ }
+
+ ret = wmt_check_status(i2c_dev);
+ if (ret)
+ break;
+
+ xfer_len++;
+
+ val = readw(i2c_dev->base + REG_CSR);
+ if ((val & CSR_RCV_ACK_MASK) == CSR_RCV_NOT_ACK) {
+ dev_dbg(i2c_dev->dev, "write RCV NACK error\n");
+ ret = -EIO;
+ break;
+ }
+
+ if (pmsg->len == 0) {
+ val = CR_TX_END | CR_CPU_RDY | CR_ENABLE;
+ writew(val, i2c_dev->base + REG_CR);
+ break;
+ }
+
+ if (pmsg->len > xfer_len) {
+ writew(pmsg->buf[xfer_len] & 0xFF, i2c_dev->base +
+ REG_CDR);
+ writew(CR_CPU_RDY | CR_ENABLE, i2c_dev->base + REG_CR);
+ } else if (pmsg->len == xfer_len) {
+ if (last != 1)
+ writew(CR_ENABLE, i2c_dev->base + REG_CR);
+ break;
+ } else {
+ dev_dbg(i2c_dev->dev, "unknown error (tx)\n");
+ ret = -EIO;
+ break;
+ }
+ }
+
+ return ret;
+}
+
+static int wmt_i2c_read(struct i2c_adapter *adap, struct i2c_msg *pmsg,
+ int restart, int last)
+{
+ struct wmt_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
+ u16 val;
+ u16 tcr_val;
+ int ret;
+ int wait_result;
+ u32 xfer_len = 0;
+
+ if (pmsg->len <= 0)
+ return -EINVAL;
+
+ if (restart == 0) {
+ ret = wmt_i2c_wait_bus_not_busy(i2c_dev);
+ if (ret < 0)
+ return ret;
+ }
+
+ val = readw(i2c_dev->base + REG_CR);
+ val &= ~CR_TX_END;
+ writew(val, i2c_dev->base + REG_CR);
+
+ val = readw(i2c_dev->base + REG_CR);
+ val &= ~CR_TX_NEXT_NO_ACK;
+ writew(val, i2c_dev->base + REG_CR);
+
+ if (restart == 0) {
+ val = readw(i2c_dev->base + REG_CR);
+ val |= CR_CPU_RDY;
+ writew(val, i2c_dev->base + REG_CR);
+ }
+
+ if (pmsg->len == 1) {
+ val = readw(i2c_dev->base + REG_CR);
+ val |= CR_TX_NEXT_NO_ACK;
+ writew(val, i2c_dev->base + REG_CR);
+ }
+
+ init_completion(&i2c_dev->complete);
+
+ if (i2c_dev->mode == I2C_MODE_STANDARD)
+ tcr_val = TCR_STANDARD_MODE;
+ else
+ tcr_val = TCR_FAST_MODE;
+
+ tcr_val |= TCR_MASTER_READ | (pmsg->addr & TCR_SLAVE_ADDR_MASK);
+
+ writew(tcr_val, i2c_dev->base + REG_TCR);
+
+ if (restart == 1) {
+ val = readw(i2c_dev->base + REG_CR);
+ val |= CR_CPU_RDY;
+ writew(val, i2c_dev->base + REG_CR);
+ }
+
+ ret = 0;
+
+ for (;;) {
+ wait_result = wait_for_completion_interruptible_timeout(
+ &i2c_dev->complete, 500 * HZ / 1000);
+
+ if (wait_result == 0) {
+ dev_dbg(i2c_dev->dev, "wait timeout (tx)\n");
+ ret = -ETIMEDOUT;
+ break;
+ }
+
+ ret = wmt_check_status(i2c_dev);
+ if (ret)
+ break;
+
+ pmsg->buf[xfer_len] = readw(i2c_dev->base + REG_CDR) >> 8;
+ xfer_len++;
+
+ if (pmsg->len > xfer_len) {
+ if (pmsg->len - 1 == xfer_len) {
+ val = readw(i2c_dev->base + REG_CR);
+ val |= (CR_TX_NEXT_NO_ACK | CR_CPU_RDY);
+ writew(val, i2c_dev->base + REG_CR);
+ } else {
+ val = readw(i2c_dev->base + REG_CR);
+ val |= CR_CPU_RDY;
+ writew(val, i2c_dev->base + REG_CR);
+ }
+ } else if (pmsg->len == xfer_len) {
+ break;
+ } else {
+ ret = -EIO;
+ break;
+ }
+ }
+
+ return ret;
+}
+
+static int wmt_i2c_xfer(struct i2c_adapter *adap,
+ struct i2c_msg msgs[],
+ int num)
+{
+ struct i2c_msg *pmsg;
+ int i;
+ int ret = 0;
+ int is_last;
+ int restart;
+
+ for (i = 0; ret >= 0 && i < num; i++) {
+ is_last = ((i + 1) == num);
+ restart = (i != 0);
+
+ pmsg = &msgs[i];
+ if (pmsg->flags & I2C_M_NOSTART)
+ restart = 1;
+ if (pmsg->flags & I2C_M_RD)
+ ret = wmt_i2c_read(adap, pmsg, restart, is_last);
+ else
+ ret = wmt_i2c_write(adap, pmsg, restart, is_last);
+ }
+
+ if (ret < 0)
+ return ret;
+ else
+ return i;
+}
+
+static u32 wmt_i2c_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm wmt_i2c_algo = {
+ .master_xfer = wmt_i2c_xfer,
+ .functionality = wmt_i2c_func,
+};
+
+static irqreturn_t wmt_i2c_isr(int irq, void *data)
+{
+ struct wmt_i2c_dev *i2c_dev = data;
+
+ /* save the status and write-clear it */
+ i2c_dev->cmd_status = readw(i2c_dev->base + REG_ISR);
+ writew(i2c_dev->cmd_status, i2c_dev->base + REG_ISR);
+
+ complete(&i2c_dev->complete);
+
+ return IRQ_HANDLED;
+}
+
+/*
+ * Due to a lack of pinmux functionality we need to manually configure
+ * the GPIO pullup. Once pinmux is implemented, this function should be
+ * removed. Pullup's are not available on vt8500 or wm8505 so we skip.
+ */
+static int wmt_i2c_setup_gpio(struct wmt_i2c_dev *i2c_dev)
+{
+ struct device_node *np;
+ void __iomem *gpio_base;
+ int nr = i2c_dev->adapter.nr;
+ u8 val;
+ u8 mask;
+
+ /* VT8500 - has external pullups so no configuration required. */
+ if (of_machine_is_compatible("via,vt8500"))
+ return 0;
+
+ /*
+ * WM8505 - has external pullups but we need to config the alt func
+ * WM8650 - has programmable pullups + alt func
+ * WM8850 - has programmable pullups + alt func
+ */
+ if (of_machine_is_compatible("wm,wm8505")) {
+ np = of_find_compatible_node(NULL, NULL, "wm,wm8505-gpio");
+ if (!np) {
+ dev_err(i2c_dev->dev, "GPIO required for WM8505 i2c\n");
+ return -EINVAL;
+ }
+ } else if (of_machine_is_compatible("wm,wm8650") ||
+ of_machine_is_compatible("wm,wm8850")) {
+ np = of_find_compatible_node(NULL, NULL, "wm,wm8650-gpio");
+ if (!np) {
+ dev_err(i2c_dev->dev, "GPIO required for WM8650 i2c\n");
+ return -EINVAL;
+ }
+ } else {
+ /* If we don't know what machine, assume its configured */
+ dev_warn(i2c_dev->dev, "unrecognised machine\n");
+ return 0;
+ }
+
+ gpio_base = of_iomap(np, 0);
+ if (!gpio_base) {
+ dev_err(i2c_dev->dev, "failed to map gpio memory\n");
+ return -ENOMEM;
+ }
+
+ if (of_machine_is_compatible("wm,wm8505")) {
+ if (nr == 0) {
+ /* Set gpio pins to alt function */
+ val = readb(gpio_base + 0x500);
+ writeb(val & 0xFC, gpio_base + 0x500);
+ }
+ } else if (of_machine_is_compatible("wm,wm8650")) {
+ if (nr == 0) {
+ /* set gpio pins to alt function */
+ val = readb(gpio_base + 0x55);
+ val &= ~(BIT(0) | BIT(1));
+ writeb(val, gpio_base + 0x55);
+
+ /* enable pull */
+ val = readb(gpio_base + 0x495);
+ val |= (BIT(0) | BIT(1));
+ writeb(val, gpio_base + 0x495);
+
+ /* set pulled-up */
+ val = readb(gpio_base + 0x4D5);
+ val |= (BIT(0) | BIT(1));
+ writeb(val, gpio_base + 0x4D5);
+ } else if (nr == 1) {
+ /* set gpio pins to alt function */
+ val = readb(gpio_base + 0x49);
+ val &= ~(BIT(4) | BIT(5));
+ writeb(val, gpio_base + 0x49);
+
+ /* enable pull */
+ val = readb(gpio_base + 0x489);
+ val |= (BIT(4) | BIT(5));
+ writeb(val, gpio_base + 0x489);
+
+ /* set pulled-up */
+ val = readb(gpio_base + 0x4C9);
+ val |= (BIT(4) | BIT(5));
+ writeb(val, gpio_base + 0x4C9);
+ }
+ } else if (of_machine_is_compatible("wm,wm8850")) {
+ if ((nr >= 0) && (nr <= 2)) {
+ mask = 0x03 << (nr << 1);
+
+ /* set gpio pins to alt function */
+ val = readb(gpio_base + 0x55);
+ val &= ~mask;
+ writeb(val, gpio_base + 0x55);
+
+ /* enable pull */
+ val = readb(gpio_base + 0x495);
+ val |= mask;
+ writeb(val, gpio_base + 0x495);
+
+ /* set pulled-up */
+ val = readb(gpio_base + 0x4D5);
+ val |= mask;
+ writeb(val, gpio_base + 0x4D5);
+ }
+ }
+
+
+ iounmap(gpio_base);
+
+ return 0;
+}
+
+static int wmt_i2c_reset_hardware(struct wmt_i2c_dev *i2c_dev)
+{
+ int err;
+
+ err = clk_prepare_enable(i2c_dev->clk);
+ if (err) {
+ dev_err(i2c_dev->dev, "failed to enable clock\n");
+ return err;
+ }
+
+ err = clk_set_rate(i2c_dev->clk, 20000000);
+ if (err) {
+ dev_err(i2c_dev->dev, "failed to set clock = 20Mhz\n");
+ return err;
+ }
+
+ err = wmt_i2c_setup_gpio(i2c_dev);
+ if (err)
+ return err;
+
+ writew(0, i2c_dev->base + REG_CR);
+ writew(12, i2c_dev->base + REG_MCR);
+ writew(ISR_WRITE_ALL, i2c_dev->base + REG_ISR);
+ writew(IMR_ENABLE_ALL, i2c_dev->base + REG_IMR);
+ writew(CR_ENABLE, i2c_dev->base + REG_CR);
+ readw(i2c_dev->base + REG_CSR); /* read clear */
+ writew(ISR_WRITE_ALL, i2c_dev->base + REG_ISR);
+
+ if (i2c_dev->mode == I2C_MODE_STANDARD)
+ writew(0x8064, i2c_dev->base + REG_TR);
+ else
+ writew(0x8019, i2c_dev->base + REG_TR);
+
+ return 0;
+}
+
+static int wmt_i2c_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct wmt_i2c_dev *i2c_dev;
+ struct i2c_adapter *adap;
+ struct resource *res;
+ int err;
+ u32 clk_rate;
+
+ if (!np) {
+ dev_err(&pdev->dev, "device node not found\n");
+ return -ENODEV;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "no memory resource defined\n");
+ return -ENODEV;
+ }
+
+ i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
+ if (!i2c_dev) {
+ dev_err(&pdev->dev, "device memory allocation failed\n");
+ return -ENOMEM;
+ }
+
+ i2c_dev->base = devm_request_and_ioremap(&pdev->dev, res);
+ if (!i2c_dev->base) {
+ dev_err(&pdev->dev, "memory region unavailable\n");
+ return -ENOMEM;
+ }
+
+ i2c_dev->irq = irq_of_parse_and_map(np, 0);
+ if (!i2c_dev->irq) {
+ dev_err(&pdev->dev, "irq missing or invalid\n");
+ return -EINVAL;
+ }
+
+ i2c_dev->clk = of_clk_get(np, 0);
+ if (IS_ERR(i2c_dev->clk)) {
+ dev_err(&pdev->dev, "unable to request clock\n");
+ return PTR_ERR(i2c_dev->clk);
+ }
+
+ i2c_dev->mode = I2C_MODE_STANDARD;
+ err = of_property_read_u32(np, "clock-frequency", &clk_rate);
+ if ((!err) && (clk_rate == 400000))
+ i2c_dev->mode = I2C_MODE_FAST;
+
+ i2c_dev->dev = &pdev->dev;
+
+ err = devm_request_irq(&pdev->dev, i2c_dev->irq, wmt_i2c_isr, 0,
+ "i2c", i2c_dev);
+ if (err) {
+ dev_err(&pdev->dev, "failed to request irq %i\n", i2c_dev->irq);
+ return err;
+ }
+
+ adap = &i2c_dev->adapter;
+ i2c_set_adapdata(adap, i2c_dev);
+ strlcpy(adap->name, "WMT I2C adapter", sizeof(adap->name));
+ adap->owner = THIS_MODULE;
+ adap->class = I2C_CLASS_HWMON;
+ adap->algo = &wmt_i2c_algo;
+ adap->dev.parent = &pdev->dev;
+ adap->dev.of_node = pdev->dev.of_node;
+ adap->nr = of_alias_get_id(pdev->dev.of_node, "i2c");
+
+ err = wmt_i2c_reset_hardware(i2c_dev);
+ if (err) {
+ dev_err(&pdev->dev, "error initializing hardware\n");
+ return err;
+ }
+
+ if (adap->nr < 0)
+ err = i2c_add_adapter(adap);
+ else
+ err = i2c_add_numbered_adapter(adap);
+
+ if (err) {
+ dev_err(&pdev->dev, "failed to add adapter\n");
+ return err;
+ }
+
+ platform_set_drvdata(pdev, i2c_dev);
+
+ of_i2c_register_devices(adap);
+
+ return 0;
+}
+
+static int wmt_i2c_remove(struct platform_device *pdev)
+{
+ struct wmt_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
+
+ i2c_del_adapter(&i2c_dev->adapter);
+
+ return 0;
+}
+
+static struct of_device_id wmt_i2c_dt_ids[] = {
+ { .compatible = "wm,wm8505-i2c" },
+ { /* Sentinel */ },
+};
+
+static struct platform_driver wmt_i2c_driver = {
+ .probe = wmt_i2c_probe,
+ .remove = wmt_i2c_remove,
+ .driver = {
+ .name = "wmt-i2c",
+ .owner = THIS_MODULE,
+ .of_match_table = wmt_i2c_dt_ids,
+ },
+};
+
+module_platform_driver(wmt_i2c_driver);
+
+MODULE_DESCRIPTION("Wondermedia I2C master-mode bus adapter");
+MODULE_AUTHOR("Tony Prisk <linux@prisktech.co.nz>");
+MODULE_LICENSE("GPL v2");
+MODULE_DEVICE_TABLE(of, wmt_i2c_dt_ids);
This patch adds support for the I2C controller found on Wondermedia SoCs. Due to the lack of pinmux support, GPIO pin alternate functions are configured by machine's compatible property, as are pullups. Signed-off-by: Tony Prisk <linux@prisktech.co.nz> --- .../devicetree/bindings/i2c/i2c-vt8500.txt | 24 + drivers/i2c/busses/Kconfig | 7 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-wmt.c | 636 ++++++++++++++++++++ 4 files changed, 668 insertions(+) create mode 100644 Documentation/devicetree/bindings/i2c/i2c-vt8500.txt create mode 100644 drivers/i2c/busses/i2c-wmt.c