[RFC 04/21] drm: bridge/dw_hdmi: add dw hdmi i2c bus adapter support
Ulrich Hecht
ulrich.hecht+renesas at gmail.com
Mon May 30 16:00:03 UTC 2016
From: Vladimir Zapolskiy <vladimir_zapolskiy at mentor.com>
The change adds support of internal HDMI I2C master controller, this
subdevice is used by default, if "ddc-i2c-bus" DT property is omitted.
The main purpose of this functionality is to support reading EDID from
an HDMI monitor on boards, which don't have an I2C bus connected to
DDC pins.
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy at mentor.com>
Signed-off-by: Koji Matsuoka <koji.matsuoka.xm at renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas at glider.be>
---
drivers/gpu/drm/bridge/dw-hdmi.c | 331 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 325 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/bridge/dw-hdmi.c b/drivers/gpu/drm/bridge/dw-hdmi.c
index c9d9412..1cfff2f 100644
--- a/drivers/gpu/drm/bridge/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/dw-hdmi.c
@@ -1,14 +1,15 @@
/*
+ * DesignWare High-Definition Multimedia Interface (HDMI) driver
+ *
+ * Copyright (C) 2013-2015 Mentor Graphics Inc.
* Copyright (C) 2011-2013 Freescale Semiconductor, Inc.
+ * Copyright (C) 2010, Guennadi Liakhovetski <g.liakhovetski at gmx.de>
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
- * Designware High-Definition Multimedia Interface (HDMI) driver
- *
- * Copyright (C) 2010, Guennadi Liakhovetski <g.liakhovetski at gmx.de>
*/
#include <linux/module.h>
#include <linux/irq.h>
@@ -31,6 +32,26 @@
#include "dw-hdmi.h"
#include "dw-hdmi-audio.h"
+/* HDMI_IH_I2CM_STAT0 and HDMI_IH_MUTE_I2CM_STAT0 register bits */
+#define HDMI_IH_I2CM_STAT0_ERROR BIT(0)
+#define HDMI_IH_I2CM_STAT0_DONE BIT(1)
+
+/* HDMI_I2CM_OPERATION register bits */
+#define HDMI_I2CM_OPERATION_READ BIT(0)
+#define HDMI_I2CM_OPERATION_READ_EXT BIT(1)
+#define HDMI_I2CM_OPERATION_WRITE BIT(4)
+
+/* HDMI_I2CM_INT register bits */
+#define HDMI_I2CM_INT_DONE_MASK BIT(2)
+#define HDMI_I2CM_INT_DONE_POL BIT(3)
+
+/* HDMI_I2CM_CTLINT register bits */
+#define HDMI_I2CM_CTLINT_ARB_MASK BIT(2)
+#define HDMI_I2CM_CTLINT_ARB_POL BIT(3)
+#define HDMI_I2CM_CTLINT_NAC_MASK BIT(6)
+#define HDMI_I2CM_CTLINT_NAC_POL BIT(7)
+
+
#define HDMI_EDID_LEN 512
#define RGB 0
@@ -101,6 +122,17 @@ struct hdmi_data_info {
struct hdmi_vmode video_mode;
};
+struct dw_hdmi_i2c {
+ struct i2c_adapter adap;
+
+ spinlock_t lock;
+ struct completion cmp;
+ u8 stat;
+
+ u8 slave_reg;
+ bool is_regaddr;
+};
+
struct dw_hdmi {
struct drm_connector connector;
struct drm_encoder *encoder;
@@ -111,6 +143,7 @@ struct dw_hdmi {
struct device *dev;
struct clk *isfr_clk;
struct clk *iahb_clk;
+ struct dw_hdmi_i2c *i2c;
struct hdmi_data_info hdmi_data;
const struct dw_hdmi_plat_data *plat_data;
@@ -198,6 +231,242 @@ static void hdmi_mask_writeb(struct dw_hdmi *hdmi, u8 data, unsigned int reg,
hdmi_modb(hdmi, data << shift, mask, reg);
}
+static void dw_hdmi_i2c_init(struct dw_hdmi *hdmi)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&hdmi->i2c->lock, flags);
+
+ /* Set Fast Mode speed */
+ hdmi_writeb(hdmi, 0x0b, HDMI_I2CM_DIV);
+
+ /* Software reset */
+ hdmi_writeb(hdmi, 0x00, HDMI_I2CM_SOFTRSTZ);
+
+ /* Set done, not acknowledged and arbitration interrupt polarities */
+ hdmi_writeb(hdmi, HDMI_I2CM_INT_DONE_POL, HDMI_I2CM_INT);
+ hdmi_writeb(hdmi, HDMI_I2CM_CTLINT_NAC_POL | HDMI_I2CM_CTLINT_ARB_POL,
+ HDMI_I2CM_CTLINT);
+
+ /* Clear DONE and ERROR interrupts */
+ hdmi_writeb(hdmi, HDMI_IH_I2CM_STAT0_ERROR | HDMI_IH_I2CM_STAT0_DONE,
+ HDMI_IH_I2CM_STAT0);
+
+ /* Mute DONE and ERROR interrupts */
+ hdmi_writeb(hdmi, HDMI_IH_I2CM_STAT0_ERROR | HDMI_IH_I2CM_STAT0_DONE,
+ HDMI_IH_MUTE_I2CM_STAT0);
+
+ spin_unlock_irqrestore(&hdmi->i2c->lock, flags);
+}
+
+static int dw_hdmi_i2c_read(struct dw_hdmi *hdmi,
+ unsigned char *buf, int length)
+{
+ int stat;
+ unsigned long flags;
+ struct dw_hdmi_i2c *i2c = hdmi->i2c;
+
+ spin_lock_irqsave(&i2c->lock, flags);
+
+ if (!i2c->is_regaddr) {
+ dev_dbg(hdmi->dev, "set read register address to 0\n");
+ i2c->slave_reg = 0x00;
+ i2c->is_regaddr = true;
+ }
+
+ while (length--) {
+ hdmi_writeb(hdmi, i2c->slave_reg++, HDMI_I2CM_ADDRESS);
+ hdmi_writeb(hdmi,
+ HDMI_I2CM_OPERATION_READ, HDMI_I2CM_OPERATION);
+ i2c->stat = 0;
+
+ spin_unlock_irqrestore(&i2c->lock, flags);
+
+ stat = wait_for_completion_interruptible_timeout(&i2c->cmp,
+ HZ / 10);
+ if (!stat)
+ return -ETIMEDOUT;
+ if (stat < 0)
+ return stat;
+
+ spin_lock_irqsave(&i2c->lock, flags);
+
+ /* Check for error condition on the bus */
+ if (i2c->stat & HDMI_IH_I2CM_STAT0_ERROR) {
+ spin_unlock_irqrestore(&i2c->lock, flags);
+ return -EIO;
+ }
+
+ *buf++ = hdmi_readb(hdmi, HDMI_I2CM_DATAI);
+ }
+
+ spin_unlock_irqrestore(&i2c->lock, flags);
+
+ return 0;
+}
+
+static int dw_hdmi_i2c_write(struct dw_hdmi *hdmi,
+ unsigned char *buf, int length)
+{
+ int stat;
+ unsigned long flags;
+ struct dw_hdmi_i2c *i2c = hdmi->i2c;
+
+ spin_lock_irqsave(&i2c->lock, flags);
+
+ if (!i2c->is_regaddr) {
+ if (length) {
+ /* Use the first write byte as register address */
+ i2c->slave_reg = buf[0];
+ length--;
+ buf++;
+ } else {
+ dev_dbg(hdmi->dev, "set write register address to 0\n");
+ i2c->slave_reg = 0x00;
+ }
+ i2c->is_regaddr = true;
+ }
+
+ while (length--) {
+ hdmi_writeb(hdmi, *buf++, HDMI_I2CM_DATAO);
+ hdmi_writeb(hdmi, i2c->slave_reg++, HDMI_I2CM_ADDRESS);
+ hdmi_writeb(hdmi,
+ HDMI_I2CM_OPERATION_WRITE, HDMI_I2CM_OPERATION);
+ i2c->stat = 0;
+
+ spin_unlock_irqrestore(&i2c->lock, flags);
+
+ stat = wait_for_completion_interruptible_timeout(&i2c->cmp,
+ HZ / 10);
+ if (!stat)
+ return -ETIMEDOUT;
+ if (stat < 0)
+ return stat;
+
+ spin_lock_irqsave(&i2c->lock, flags);
+
+ /* Check for error condition on the bus */
+ if (i2c->stat & HDMI_IH_I2CM_STAT0_ERROR) {
+ spin_unlock_irqrestore(&i2c->lock, flags);
+ return -EIO;
+ }
+ }
+
+ spin_unlock_irqrestore(&i2c->lock, flags);
+
+ return 0;
+}
+
+static int dw_hdmi_i2c_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ struct dw_hdmi *hdmi = i2c_get_adapdata(adap);
+ struct dw_hdmi_i2c *i2c = hdmi->i2c;
+
+ int i, ret;
+ u8 addr;
+ unsigned long flags;
+
+ dev_dbg(hdmi->dev, "xfer: num: %d, addr: 0x%x\n", num, msgs[0].addr);
+
+ spin_lock_irqsave(&i2c->lock, flags);
+
+ hdmi_writeb(hdmi, 0x00, HDMI_IH_MUTE_I2CM_STAT0);
+
+ /* Set slave device address from the first transaction */
+ addr = msgs[0].addr;
+ hdmi_writeb(hdmi, addr, HDMI_I2CM_SLAVE);
+
+ /* Set slave device register address on transfer */
+ i2c->is_regaddr = false;
+
+ spin_unlock_irqrestore(&i2c->lock, flags);
+
+ for (i = 0; i < num; i++) {
+ dev_dbg(hdmi->dev, "xfer: num: %d/%d, len: %d, flags: 0x%x\n",
+ i + 1, num, msgs[i].len, msgs[i].flags);
+
+ if (msgs[i].addr != addr) {
+ dev_warn(hdmi->dev,
+ "unsupported transaction, changed slave address\n");
+ ret = -EOPNOTSUPP;
+ break;
+ }
+
+ if (msgs[i].len == 0) {
+ dev_dbg(hdmi->dev,
+ "unsupported transaction %d/%d, no data\n",
+ i + 1, num);
+ ret = -EOPNOTSUPP;
+ break;
+ }
+
+ if (msgs[i].flags & I2C_M_RD)
+ ret = dw_hdmi_i2c_read(hdmi, msgs[i].buf, msgs[i].len);
+ else
+ ret = dw_hdmi_i2c_write(hdmi, msgs[i].buf, msgs[i].len);
+
+ if (ret < 0)
+ break;
+ }
+
+ if (!ret)
+ ret = num;
+
+ spin_lock_irqsave(&i2c->lock, flags);
+
+ /* Mute DONE and ERROR interrupts */
+ hdmi_writeb(hdmi, HDMI_IH_I2CM_STAT0_ERROR | HDMI_IH_I2CM_STAT0_DONE,
+ HDMI_IH_MUTE_I2CM_STAT0);
+
+ spin_unlock_irqrestore(&i2c->lock, flags);
+
+ return ret;
+}
+
+static u32 dw_hdmi_i2c_func(struct i2c_adapter *adapter)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static struct i2c_algorithm dw_hdmi_algorithm = {
+ .master_xfer = dw_hdmi_i2c_xfer,
+ .functionality = dw_hdmi_i2c_func,
+};
+
+static struct i2c_adapter *dw_hdmi_i2c_adapter(struct dw_hdmi *hdmi)
+{
+ struct i2c_adapter *adap;
+ int ret;
+
+ hdmi->i2c = devm_kzalloc(hdmi->dev, sizeof(*hdmi->i2c), GFP_KERNEL);
+ if (!hdmi->i2c)
+ return ERR_PTR(-ENOMEM);
+
+ spin_lock_init(&hdmi->i2c->lock);
+ init_completion(&hdmi->i2c->cmp);
+
+ adap = &hdmi->i2c->adap;
+ adap->class = I2C_CLASS_DDC;
+ adap->owner = THIS_MODULE;
+ adap->dev.parent = hdmi->dev;
+ adap->algo = &dw_hdmi_algorithm;
+ strlcpy(adap->name, "DesignWare HDMI", sizeof(adap->name));
+ i2c_set_adapdata(adap, hdmi);
+
+ ret = i2c_add_adapter(adap);
+ if (ret) {
+ dev_warn(hdmi->dev, "cannot add %s I2C adapter\n", adap->name);
+ devm_kfree(hdmi->dev, hdmi->i2c);
+ hdmi->i2c = NULL;
+ return ERR_PTR(ret);
+ }
+
+ dev_info(hdmi->dev, "registered %s I2C bus driver\n", adap->name);
+
+ return adap;
+}
+
static void hdmi_set_cts_n(struct dw_hdmi *hdmi, unsigned int cts,
unsigned int n)
{
@@ -1534,16 +1803,47 @@ static const struct drm_bridge_funcs dw_hdmi_bridge_funcs = {
.mode_set = dw_hdmi_bridge_mode_set,
};
+static irqreturn_t dw_hdmi_i2c_irq(struct dw_hdmi *hdmi)
+{
+ struct dw_hdmi_i2c *i2c = hdmi->i2c;
+ unsigned long flags;
+
+ spin_lock_irqsave(&i2c->lock, flags);
+
+ i2c->stat = hdmi_readb(hdmi, HDMI_IH_I2CM_STAT0);
+ if (!i2c->stat) {
+ spin_unlock_irqrestore(&i2c->lock, flags);
+ return IRQ_NONE;
+ }
+
+ hdmi_writeb(hdmi, i2c->stat, HDMI_IH_I2CM_STAT0);
+ complete(&i2c->cmp);
+
+ dev_dbg(hdmi->dev, "i2cm_stat: 0x%02x, addr: 0x%02x, reg: 0x%02x\n",
+ i2c->stat, hdmi_readb(hdmi, HDMI_I2CM_SLAVE),
+ hdmi_readb(hdmi, HDMI_I2CM_ADDRESS));
+
+ spin_unlock_irqrestore(&i2c->lock, flags);
+
+ return IRQ_HANDLED;
+}
+
static irqreturn_t dw_hdmi_hardirq(int irq, void *dev_id)
{
struct dw_hdmi *hdmi = dev_id;
u8 intr_stat;
+ irqreturn_t ret = IRQ_NONE;
+
+ if (hdmi->i2c)
+ ret = dw_hdmi_i2c_irq(hdmi);
intr_stat = hdmi_readb(hdmi, HDMI_IH_PHY_STAT0);
- if (intr_stat)
+ if (intr_stat) {
hdmi_writeb(hdmi, ~0, HDMI_IH_MUTE_PHY_STAT0);
+ return IRQ_WAKE_THREAD;
+ }
- return intr_stat ? IRQ_WAKE_THREAD : IRQ_NONE;
+ return ret;
}
static irqreturn_t dw_hdmi_irq(int irq, void *dev_id)
@@ -1771,6 +2071,13 @@ int dw_hdmi_bind(struct device *dev, struct device *master,
*/
hdmi_init_clk_regenerator(hdmi);
+ /* If DDC bus is not specified, try to register HDMI I2C bus */
+ if (!hdmi->ddc) {
+ hdmi->ddc = dw_hdmi_i2c_adapter(hdmi);
+ if (IS_ERR(hdmi->ddc))
+ hdmi->ddc = NULL;
+ }
+
/*
* Configure registers related to HDMI interrupt
* generation before registering IRQ.
@@ -1811,11 +2118,18 @@ int dw_hdmi_bind(struct device *dev, struct device *master,
hdmi->audio = platform_device_register_full(&pdevinfo);
}
+ /* Unmute I2CM interrupts and reset HDMI DDC I2C master controller */
+ if (hdmi->i2c)
+ dw_hdmi_i2c_init(hdmi);
+
dev_set_drvdata(dev, hdmi);
return 0;
err_iahb:
+ if (hdmi->i2c)
+ i2c_del_adapter(&hdmi->i2c->adap);
+
clk_disable_unprepare(hdmi->iahb_clk);
err_isfr:
clk_disable_unprepare(hdmi->isfr_clk);
@@ -1839,13 +2153,18 @@ void dw_hdmi_unbind(struct device *dev, struct device *master, void *data)
clk_disable_unprepare(hdmi->iahb_clk);
clk_disable_unprepare(hdmi->isfr_clk);
- i2c_put_adapter(hdmi->ddc);
+
+ if (hdmi->i2c)
+ i2c_del_adapter(&hdmi->i2c->adap);
+ else
+ i2c_put_adapter(hdmi->ddc);
}
EXPORT_SYMBOL_GPL(dw_hdmi_unbind);
MODULE_AUTHOR("Sascha Hauer <s.hauer at pengutronix.de>");
MODULE_AUTHOR("Andy Yan <andy.yan at rock-chips.com>");
MODULE_AUTHOR("Yakir Yang <ykk at rock-chips.com>");
+MODULE_AUTHOR("Vladimir Zapolskiy <vladimir_zapolskiy at mentor.com>");
MODULE_DESCRIPTION("DW HDMI transmitter driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:dw-hdmi");
--
2.7.4
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