FROMLIST: drm: bridge/dw_hdmi: add dw hdmi i2c bus adapter support
[firefly-linux-kernel-4.4.55.git] / drivers / gpu / drm / bridge / dw-hdmi.c
index c5d7b27fd90d6992fa92dbdb765aeacfcff9a7bb..a01d357aca0181c081895f1f5e5f1b877067aeeb 100644 (file)
@@ -1,5 +1,9 @@
 /*
+ * 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@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
@@ -8,7 +12,6 @@
  *
  * Designware High-Definition Multimedia Interface (HDMI) driver
  *
- * Copyright (C) 2010, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
  */
 #include <linux/module.h>
 #include <linux/irq.h>
@@ -157,6 +160,17 @@ struct hdmi_data_info {
        struct hdmi_vmode video_mode;
 };
 
+struct dw_hdmi_i2c {
+       struct i2c_adapter      adap;
+
+       struct mutex            lock;
+       struct completion       cmp;
+       u8                      stat;
+
+       u8                      slave_reg;
+       bool                    is_regaddr;
+};
+
 struct dw_hdmi {
        struct drm_connector connector;
        struct drm_encoder *encoder;
@@ -167,6 +181,7 @@ 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;
@@ -254,6 +269,200 @@ 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)
+{
+       /* 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);
+}
+
+static int dw_hdmi_i2c_read(struct dw_hdmi *hdmi,
+                           unsigned char *buf, unsigned int length)
+{
+       struct dw_hdmi_i2c *i2c = hdmi->i2c;
+       int stat;
+
+       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--) {
+               reinit_completion(&i2c->cmp);
+
+               hdmi_writeb(hdmi, i2c->slave_reg++, HDMI_I2CM_ADDRESS);
+               hdmi_writeb(hdmi, HDMI_I2CM_OPERATION_READ,
+                           HDMI_I2CM_OPERATION);
+
+               stat = wait_for_completion_timeout(&i2c->cmp, HZ / 10);
+               if (!stat)
+                       return -EAGAIN;
+
+               /* Check for error condition on the bus */
+               if (i2c->stat & HDMI_IH_I2CM_STAT0_ERROR)
+                       return -EIO;
+
+               *buf++ = hdmi_readb(hdmi, HDMI_I2CM_DATAI);
+       }
+
+       return 0;
+}
+
+static int dw_hdmi_i2c_write(struct dw_hdmi *hdmi,
+                            unsigned char *buf, unsigned int length)
+{
+       struct dw_hdmi_i2c *i2c = hdmi->i2c;
+       int stat;
+
+       if (!i2c->is_regaddr) {
+               /* Use the first write byte as register address */
+               i2c->slave_reg = buf[0];
+               length--;
+               buf++;
+               i2c->is_regaddr = true;
+       }
+
+       while (length--) {
+               reinit_completion(&i2c->cmp);
+
+               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);
+
+       stat = wait_for_completion_timeout(&i2c->cmp, HZ / 10);
+               if (!stat)
+                       return -EAGAIN;
+
+               /* Check for error condition on the bus */
+               if (i2c->stat & HDMI_IH_I2CM_STAT0_ERROR)
+                       return -EIO;
+       }
+
+       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;
+       u8 addr = msgs[0].addr;
+       int i, ret = 0;
+
+       dev_dbg(hdmi->dev, "xfer: num: %d, addr: %#x\n", num, addr);
+
+       for (i = 0; i < num; i++) {
+               if (msgs[i].addr != addr) {
+                       dev_warn(hdmi->dev,
+                                "unsupported transfer, changed slave address\n");
+                       return -EOPNOTSUPP;
+               }
+
+               if (msgs[i].len == 0) {
+                       dev_dbg(hdmi->dev,
+                               "unsupported transfer %d/%d, no data\n",
+                               i + 1, num);
+                       return -EOPNOTSUPP;
+               }
+       }
+
+       mutex_lock(&i2c->lock);
+
+       hdmi_writeb(hdmi, 0x00, HDMI_IH_MUTE_I2CM_STAT0);
+
+       /* Set slave device address taken from the first I2C message */
+       hdmi_writeb(hdmi, addr, HDMI_I2CM_SLAVE);
+
+       /* Set slave device register address on transfer */
+       i2c->is_regaddr = false;
+
+       for (i = 0; i < num; i++) {
+               dev_dbg(hdmi->dev, "xfer: num: %d/%d, len: %d, flags: %#x\n",
+                       i + 1, num, msgs[i].len, msgs[i].flags);
+
+               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;
+
+       /* Mute DONE and ERROR interrupts */
+       hdmi_writeb(hdmi, HDMI_IH_I2CM_STAT0_ERROR | HDMI_IH_I2CM_STAT0_DONE,
+                   HDMI_IH_MUTE_I2CM_STAT0);
+
+       mutex_unlock(&i2c->lock);
+
+       return ret;
+}
+
+static u32 dw_hdmi_i2c_func(struct i2c_adapter *adapter)
+{
+       return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const 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;
+       struct dw_hdmi_i2c *i2c;
+       int ret;
+
+       i2c = devm_kzalloc(hdmi->dev, sizeof(*i2c), GFP_KERNEL);
+       if (!i2c)
+               return ERR_PTR(-ENOMEM);
+
+       mutex_init(&i2c->lock);
+       init_completion(&i2c->cmp);
+
+       adap = &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, i2c);
+               return ERR_PTR(ret);
+       }
+
+       hdmi->i2c = i2c;
+
+       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)
 {
@@ -1654,16 +1863,40 @@ 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 int stat;
+
+       stat = hdmi_readb(hdmi, HDMI_IH_I2CM_STAT0);
+       if (!stat)
+               return IRQ_NONE;
+
+       hdmi_writeb(hdmi, stat, HDMI_IH_I2CM_STAT0);
+
+       i2c->stat = stat;
+
+       complete(&i2c->cmp);
+
+       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)
@@ -1841,6 +2074,13 @@ int dw_hdmi_bind(struct device *dev, struct device *master,
                dev_dbg(hdmi->dev, "no ddc property found\n");
        }
 
+       /* 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;
+       }
+
        hdmi->regs = devm_ioremap_resource(dev, iores);
        if (IS_ERR(hdmi->regs))
                return PTR_ERR(hdmi->regs);
@@ -1915,6 +2155,10 @@ int dw_hdmi_bind(struct device *dev, struct device *master,
        hdmi_writeb(hdmi, ~(HDMI_IH_PHY_STAT0_HPD | HDMI_IH_PHY_STAT0_RX_SENSE),
                    HDMI_IH_MUTE_PHY_STAT0);
 
+       /* Unmute I2CM interrupts and reset HDMI DDC I2C master controller */
+       if (hdmi->i2c)
+               dw_hdmi_i2c_init(hdmi);
+
        memset(&pdevinfo, 0, sizeof(pdevinfo));
        pdevinfo.parent = dev;
        pdevinfo.id = PLATFORM_DEVID_AUTO;
@@ -1955,6 +2199,9 @@ int dw_hdmi_bind(struct device *dev, struct device *master,
        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);
@@ -1978,13 +2225,18 @@ 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@pengutronix.de>");
 MODULE_AUTHOR("Andy Yan <andy.yan@rock-chips.com>");
 MODULE_AUTHOR("Yakir Yang <ykk@rock-chips.com>");
+MODULE_AUTHOR("Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>");
 MODULE_DESCRIPTION("DW HDMI transmitter driver");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:dw-hdmi");