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path: root/drivers/i2c/busses/i2c-octeon-platdrv.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-octeon-platdrv.c')
-rw-r--r--drivers/i2c/busses/i2c-octeon-platdrv.c286
1 files changed, 286 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-octeon-platdrv.c b/drivers/i2c/busses/i2c-octeon-platdrv.c
new file mode 100644
index 0000000..917524c
--- /dev/null
+++ b/drivers/i2c/busses/i2c-octeon-platdrv.c
@@ -0,0 +1,286 @@
+/*
+ * (C) Copyright 2009-2010
+ * Nokia Siemens Networks, michael.lawnick.ext@nsn.com
+ *
+ * Portions Copyright (C) 2010 - 2016 Cavium, Inc.
+ *
+ * This is a driver for the i2c adapter in Cavium Networks' OCTEON processors.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/atomic.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include <asm/octeon/octeon.h>
+#include "i2c-octeon-core.h"
+
+#define DRV_NAME "i2c-octeon"
+
+/**
+ * octeon_i2c_int_enable - enable the CORE interrupt
+ * @i2c: The struct octeon_i2c
+ *
+ * The interrupt will be asserted when there is non-STAT_IDLE state in
+ * the SW_TWSI_EOP_TWSI_STAT register.
+ */
+static void octeon_i2c_int_enable(struct octeon_i2c *i2c)
+{
+ octeon_i2c_write_int(i2c, TWSI_INT_CORE_EN);
+}
+
+/* disable the CORE interrupt */
+static void octeon_i2c_int_disable(struct octeon_i2c *i2c)
+{
+ /* clear TS/ST/IFLG events */
+ octeon_i2c_write_int(i2c, 0);
+}
+
+/**
+ * octeon_i2c_int_enable78 - enable the CORE interrupt
+ * @i2c: The struct octeon_i2c
+ *
+ * The interrupt will be asserted when there is non-STAT_IDLE state in the
+ * SW_TWSI_EOP_TWSI_STAT register.
+ */
+static void octeon_i2c_int_enable78(struct octeon_i2c *i2c)
+{
+ atomic_inc_return(&i2c->int_enable_cnt);
+ enable_irq(i2c->irq);
+}
+
+static void __octeon_i2c_irq_disable(atomic_t *cnt, int irq)
+{
+ int count;
+
+ /*
+ * The interrupt can be disabled in two places, but we only
+ * want to make the disable_irq_nosync() call once, so keep
+ * track with the atomic variable.
+ */
+ count = atomic_dec_if_positive(cnt);
+ if (count >= 0)
+ disable_irq_nosync(irq);
+}
+
+/* disable the CORE interrupt */
+static void octeon_i2c_int_disable78(struct octeon_i2c *i2c)
+{
+ __octeon_i2c_irq_disable(&i2c->int_enable_cnt, i2c->irq);
+}
+
+/**
+ * octeon_i2c_hlc_int_enable78 - enable the ST interrupt
+ * @i2c: The struct octeon_i2c
+ *
+ * The interrupt will be asserted when there is non-STAT_IDLE state in
+ * the SW_TWSI_EOP_TWSI_STAT register.
+ */
+static void octeon_i2c_hlc_int_enable78(struct octeon_i2c *i2c)
+{
+ atomic_inc_return(&i2c->hlc_int_enable_cnt);
+ enable_irq(i2c->hlc_irq);
+}
+
+/* disable the ST interrupt */
+static void octeon_i2c_hlc_int_disable78(struct octeon_i2c *i2c)
+{
+ __octeon_i2c_irq_disable(&i2c->hlc_int_enable_cnt, i2c->hlc_irq);
+}
+
+/* HLC interrupt service routine */
+static irqreturn_t octeon_i2c_hlc_isr78(int irq, void *dev_id)
+{
+ struct octeon_i2c *i2c = dev_id;
+
+ i2c->hlc_int_disable(i2c);
+ wake_up(&i2c->queue);
+
+ return IRQ_HANDLED;
+}
+
+static void octeon_i2c_hlc_int_enable(struct octeon_i2c *i2c)
+{
+ octeon_i2c_write_int(i2c, TWSI_INT_ST_EN);
+}
+
+static u32 octeon_i2c_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
+ I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_SMBUS_BLOCK_PROC_CALL;
+}
+
+static const struct i2c_algorithm octeon_i2c_algo = {
+ .master_xfer = octeon_i2c_xfer,
+ .functionality = octeon_i2c_functionality,
+};
+
+static struct i2c_adapter octeon_i2c_ops = {
+ .owner = THIS_MODULE,
+ .name = "OCTEON adapter",
+ .algo = &octeon_i2c_algo,
+};
+
+static int octeon_i2c_probe(struct platform_device *pdev)
+{
+ struct device_node *node = pdev->dev.of_node;
+ int irq, result = 0, hlc_irq = 0;
+ struct resource *res_mem;
+ struct octeon_i2c *i2c;
+ bool cn78xx_style;
+
+ cn78xx_style = of_device_is_compatible(node, "cavium,octeon-7890-twsi");
+ if (cn78xx_style) {
+ hlc_irq = platform_get_irq(pdev, 0);
+ if (hlc_irq < 0)
+ return hlc_irq;
+
+ irq = platform_get_irq(pdev, 2);
+ if (irq < 0)
+ return irq;
+ } else {
+ /* All adaptors have an irq. */
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+ }
+
+ i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
+ if (!i2c) {
+ result = -ENOMEM;
+ goto out;
+ }
+ i2c->dev = &pdev->dev;
+
+ i2c->roff.sw_twsi = 0x00;
+ i2c->roff.twsi_int = 0x10;
+ i2c->roff.sw_twsi_ext = 0x18;
+
+ res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ i2c->twsi_base = devm_ioremap_resource(&pdev->dev, res_mem);
+ if (IS_ERR(i2c->twsi_base)) {
+ result = PTR_ERR(i2c->twsi_base);
+ goto out;
+ }
+
+ /*
+ * "clock-rate" is a legacy binding, the official binding is
+ * "clock-frequency". Try the official one first and then
+ * fall back if it doesn't exist.
+ */
+ if (of_property_read_u32(node, "clock-frequency", &i2c->twsi_freq) &&
+ of_property_read_u32(node, "clock-rate", &i2c->twsi_freq)) {
+ dev_err(i2c->dev,
+ "no I2C 'clock-rate' or 'clock-frequency' property\n");
+ result = -ENXIO;
+ goto out;
+ }
+
+ i2c->sys_freq = octeon_get_io_clock_rate();
+
+ init_waitqueue_head(&i2c->queue);
+
+ i2c->irq = irq;
+
+ if (cn78xx_style) {
+ i2c->hlc_irq = hlc_irq;
+
+ i2c->int_enable = octeon_i2c_int_enable78;
+ i2c->int_disable = octeon_i2c_int_disable78;
+ i2c->hlc_int_enable = octeon_i2c_hlc_int_enable78;
+ i2c->hlc_int_disable = octeon_i2c_hlc_int_disable78;
+
+ irq_set_status_flags(i2c->irq, IRQ_NOAUTOEN);
+ irq_set_status_flags(i2c->hlc_irq, IRQ_NOAUTOEN);
+
+ result = devm_request_irq(&pdev->dev, i2c->hlc_irq,
+ octeon_i2c_hlc_isr78, 0,
+ DRV_NAME, i2c);
+ if (result < 0) {
+ dev_err(i2c->dev, "failed to attach interrupt\n");
+ goto out;
+ }
+ } else {
+ i2c->int_enable = octeon_i2c_int_enable;
+ i2c->int_disable = octeon_i2c_int_disable;
+ i2c->hlc_int_enable = octeon_i2c_hlc_int_enable;
+ i2c->hlc_int_disable = octeon_i2c_int_disable;
+ }
+
+ result = devm_request_irq(&pdev->dev, i2c->irq,
+ octeon_i2c_isr, 0, DRV_NAME, i2c);
+ if (result < 0) {
+ dev_err(i2c->dev, "failed to attach interrupt\n");
+ goto out;
+ }
+
+ if (OCTEON_IS_MODEL(OCTEON_CN38XX))
+ i2c->broken_irq_check = true;
+
+ result = octeon_i2c_init_lowlevel(i2c);
+ if (result) {
+ dev_err(i2c->dev, "init low level failed\n");
+ goto out;
+ }
+
+ octeon_i2c_set_clock(i2c);
+
+ i2c->adap = octeon_i2c_ops;
+ i2c->adap.timeout = msecs_to_jiffies(2);
+ i2c->adap.retries = 5;
+ i2c->adap.bus_recovery_info = &octeon_i2c_recovery_info;
+ i2c->adap.dev.parent = &pdev->dev;
+ i2c->adap.dev.of_node = node;
+ i2c_set_adapdata(&i2c->adap, i2c);
+ platform_set_drvdata(pdev, i2c);
+
+ result = i2c_add_adapter(&i2c->adap);
+ if (result < 0)
+ goto out;
+ dev_info(i2c->dev, "probed\n");
+ return 0;
+
+out:
+ return result;
+};
+
+static int octeon_i2c_remove(struct platform_device *pdev)
+{
+ struct octeon_i2c *i2c = platform_get_drvdata(pdev);
+
+ i2c_del_adapter(&i2c->adap);
+ return 0;
+};
+
+static const struct of_device_id octeon_i2c_match[] = {
+ { .compatible = "cavium,octeon-3860-twsi", },
+ { .compatible = "cavium,octeon-7890-twsi", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, octeon_i2c_match);
+
+static struct platform_driver octeon_i2c_driver = {
+ .probe = octeon_i2c_probe,
+ .remove = octeon_i2c_remove,
+ .driver = {
+ .name = DRV_NAME,
+ .of_match_table = octeon_i2c_match,
+ },
+};
+
+module_platform_driver(octeon_i2c_driver);
+
+MODULE_AUTHOR("Michael Lawnick <michael.lawnick.ext@nsn.com>");
+MODULE_DESCRIPTION("I2C-Bus adapter for Cavium OCTEON processors");
+MODULE_LICENSE("GPL");
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