meson: use the clock driver

[u-boot] / drivers / i2c / meson_i2c.c

diff --git a/drivers/i2c/meson_i2c.c b/drivers/i2c/meson_i2c.c
index 84e1997c760c77fc40d3af77fed06d5b2a9688fa..7d06d95cf38876092b982e3e4422eff2b446ee4f 100644 (file)
--- a/drivers/i2c/meson_i2c.c
+++ b/drivers/i2c/meson_i2c.c
@@ -1,11 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * (C) Copyright 2017 - Beniamino Galvani <b.galvani@gmail.com>
- *
- * SPDX-License-Identifier:    GPL-2.0+
  */
 #include <common.h>
-#include <asm/arch/i2c.h>
 #include <asm/io.h>
+#include <clk.h>
 #include <dm.h>
 #include <i2c.h>
 
@@ -43,13 +42,14 @@ struct i2c_regs {
 };
 
 struct meson_i2c {
+       struct clk clk;
        struct i2c_regs *regs;
-       struct i2c_msg *msg;
-       bool last;
-       uint count;
-       uint pos;
-       u32 tokens[2];
-       uint num_tokens;
+       struct i2c_msg *msg;    /* Current I2C message */
+       bool last;              /* Whether the message is the last */
+       uint count;             /* Number of bytes in the current transfer */
+       uint pos;               /* Position of current transfer in message */
+       u32 tokens[2];          /* Sequence of tokens to be written */
+       uint num_tokens;        /* Number of tokens to be written */
 };
 
 static void meson_i2c_reset_tokens(struct meson_i2c *i2c)
@@ -69,6 +69,10 @@ static void meson_i2c_add_token(struct meson_i2c *i2c, int token)
        i2c->num_tokens++;
 }
 
+/*
+ * Retrieve data for the current transfer (which can be at most 8
+ * bytes) from the device internal buffer.
+ */
 static void meson_i2c_get_data(struct meson_i2c *i2c, u8 *buf, int len)
 {
        u32 rdata0, rdata1;
@@ -86,6 +90,10 @@ static void meson_i2c_get_data(struct meson_i2c *i2c, u8 *buf, int len)
                *buf++ = (rdata1 >> (i - 4) * 8) & 0xff;
 }
 
+/*
+ * Write data for the current transfer (which can be at most 8 bytes)
+ * to the device internal buffer.
+ */
 static void meson_i2c_put_data(struct meson_i2c *i2c, u8 *buf, int len)
 {
        u32 wdata0 = 0, wdata1 = 0;
@@ -103,6 +111,11 @@ static void meson_i2c_put_data(struct meson_i2c *i2c, u8 *buf, int len)
        debug("meson i2c: write data %08x %08x len %d\n", wdata0, wdata1, len);
 }
 
+/*
+ * Prepare the next transfer: pick the next 8 bytes in the remaining
+ * part of message and write tokens and data (if needed) to the
+ * device.
+ */
 static void meson_i2c_prepare_xfer(struct meson_i2c *i2c)
 {
        bool write = !(i2c->msg->flags & I2C_M_RD);
@@ -178,7 +191,7 @@ static int meson_i2c_xfer_msg(struct meson_i2c *i2c, struct i2c_msg *msg,
 
                if (readl(&i2c->regs->ctrl) & REG_CTRL_ERROR) {
                        debug("meson i2c: error\n");
-                       return -ENXIO;
+                       return -EREMOTEIO;
                }
 
                if ((msg->flags & I2C_M_RD) && i2c->count) {
@@ -200,7 +213,7 @@ static int meson_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
        for (i = 0; i < nmsgs; i++) {
                ret = meson_i2c_xfer_msg(i2c, msg + i, i == nmsgs - 1);
                if (ret)
-                       return -EREMOTEIO;
+                       return ret;
        }
 
        return 0;
@@ -209,9 +222,13 @@ static int meson_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
 static int meson_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
 {
        struct meson_i2c *i2c = dev_get_priv(bus);
-       unsigned int clk_rate = MESON_I2C_CLK_RATE;
+       ulong clk_rate;
        unsigned int div;
 
+       clk_rate = clk_get_rate(&i2c->clk);
+       if (IS_ERR_VALUE(clk_rate))
+               return -EINVAL;
+
        div = DIV_ROUND_UP(clk_rate, speed * 4);
 
        /* clock divider has 12 bits */
@@ -226,7 +243,7 @@ static int meson_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
        clrsetbits_le32(&i2c->regs->ctrl, REG_CTRL_CLKDIVEXT_MASK,
                        (div >> 10) << REG_CTRL_CLKDIVEXT_SHIFT);
 
-       debug("meson i2c: set clk %u, src %u, div %u\n", speed, clk_rate, div);
+       debug("meson i2c: set clk %u, src %lu, div %u\n", speed, clk_rate, div);
 
        return 0;
 }
@@ -234,6 +251,15 @@ static int meson_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
 static int meson_i2c_probe(struct udevice *bus)
 {
        struct meson_i2c *i2c = dev_get_priv(bus);
+       int ret;
+
+       ret = clk_get_by_index(bus, 0, &i2c->clk);
+       if (ret < 0)
+               return ret;
+
+       ret = clk_enable(&i2c->clk);
+       if (ret)
+               return ret;
 
        i2c->regs = dev_read_addr_ptr(bus);
        clrbits_le32(&i2c->regs->ctrl, REG_CTRL_START);