From a5969cabbb4660eab42b6ef0412cbbd1200cf14d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Sat, 12 Oct 2024 07:10:09 +0000
Subject: [PATCH] 修改led为gpio
---
kernel/drivers/i2c/busses/i2c-bcm2835.c | 170 ++++++++++++++++++++++++++++++++++++++++++++------------
1 files changed, 132 insertions(+), 38 deletions(-)
diff --git a/kernel/drivers/i2c/busses/i2c-bcm2835.c b/kernel/drivers/i2c/busses/i2c-bcm2835.c
index 4d19254..ad3b124 100644
--- a/kernel/drivers/i2c/busses/i2c-bcm2835.c
+++ b/kernel/drivers/i2c/busses/i2c-bcm2835.c
@@ -1,23 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* BCM2835 master mode driver
- *
- * This software is licensed under the terms of the GNU General Public
- * License version 2, as published by the Free Software Foundation, and
- * may be copied, distributed, and modified under those terms.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
*/
#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
#include <linux/completion.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
+#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
@@ -28,6 +23,11 @@
#define BCM2835_I2C_FIFO 0x10
#define BCM2835_I2C_DIV 0x14
#define BCM2835_I2C_DEL 0x18
+/*
+ * 16-bit field for the number of SCL cycles to wait after rising SCL
+ * before deciding the slave is not responding. 0 disables the
+ * timeout detection.
+ */
#define BCM2835_I2C_CLKT 0x1c
#define BCM2835_I2C_C_READ BIT(0)
@@ -59,12 +59,11 @@
struct bcm2835_i2c_dev {
struct device *dev;
void __iomem *regs;
- struct clk *clk;
int irq;
- u32 bus_clk_rate;
struct i2c_adapter adapter;
struct completion completion;
struct i2c_msg *curr_msg;
+ struct clk *bus_clk;
int num_msgs;
u32 msg_err;
u8 *msg_buf;
@@ -82,12 +81,17 @@
return readl(i2c_dev->regs + reg);
}
-static int bcm2835_i2c_set_divider(struct bcm2835_i2c_dev *i2c_dev)
-{
- u32 divider, redl, fedl;
+#define to_clk_bcm2835_i2c(_hw) container_of(_hw, struct clk_bcm2835_i2c, hw)
+struct clk_bcm2835_i2c {
+ struct clk_hw hw;
+ struct bcm2835_i2c_dev *i2c_dev;
+};
- divider = DIV_ROUND_UP(clk_get_rate(i2c_dev->clk),
- i2c_dev->bus_clk_rate);
+static int clk_bcm2835_i2c_calc_divider(unsigned long rate,
+ unsigned long parent_rate)
+{
+ u32 divider = DIV_ROUND_UP(parent_rate, rate);
+
/*
* Per the datasheet, the register is always interpreted as an even
* number, by rounding down. In other words, the LSB is ignored. So,
@@ -96,12 +100,23 @@
if (divider & 1)
divider++;
if ((divider < BCM2835_I2C_CDIV_MIN) ||
- (divider > BCM2835_I2C_CDIV_MAX)) {
- dev_err_ratelimited(i2c_dev->dev, "Invalid clock-frequency\n");
+ (divider > BCM2835_I2C_CDIV_MAX))
return -EINVAL;
- }
- bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_DIV, divider);
+ return divider;
+}
+
+static int clk_bcm2835_i2c_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_bcm2835_i2c *div = to_clk_bcm2835_i2c(hw);
+ u32 redl, fedl;
+ u32 divider = clk_bcm2835_i2c_calc_divider(rate, parent_rate);
+
+ if (divider == -EINVAL)
+ return -EINVAL;
+
+ bcm2835_i2c_writel(div->i2c_dev, BCM2835_I2C_DIV, divider);
/*
* Number of core clocks to wait after falling edge before
@@ -116,10 +131,63 @@
*/
redl = max(divider / 4, 1u);
- bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_DEL,
+ bcm2835_i2c_writel(div->i2c_dev, BCM2835_I2C_DEL,
(fedl << BCM2835_I2C_FEDL_SHIFT) |
(redl << BCM2835_I2C_REDL_SHIFT));
return 0;
+}
+
+static long clk_bcm2835_i2c_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ u32 divider = clk_bcm2835_i2c_calc_divider(rate, *parent_rate);
+
+ return DIV_ROUND_UP(*parent_rate, divider);
+}
+
+static unsigned long clk_bcm2835_i2c_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_bcm2835_i2c *div = to_clk_bcm2835_i2c(hw);
+ u32 divider = bcm2835_i2c_readl(div->i2c_dev, BCM2835_I2C_DIV);
+
+ return DIV_ROUND_UP(parent_rate, divider);
+}
+
+static const struct clk_ops clk_bcm2835_i2c_ops = {
+ .set_rate = clk_bcm2835_i2c_set_rate,
+ .round_rate = clk_bcm2835_i2c_round_rate,
+ .recalc_rate = clk_bcm2835_i2c_recalc_rate,
+};
+
+static struct clk *bcm2835_i2c_register_div(struct device *dev,
+ struct clk *mclk,
+ struct bcm2835_i2c_dev *i2c_dev)
+{
+ struct clk_init_data init;
+ struct clk_bcm2835_i2c *priv;
+ char name[32];
+ const char *mclk_name;
+
+ snprintf(name, sizeof(name), "%s_div", dev_name(dev));
+
+ mclk_name = __clk_get_name(mclk);
+
+ init.ops = &clk_bcm2835_i2c_ops;
+ init.name = name;
+ init.parent_names = (const char* []) { mclk_name };
+ init.num_parents = 1;
+ init.flags = 0;
+
+ priv = devm_kzalloc(dev, sizeof(struct clk_bcm2835_i2c), GFP_KERNEL);
+ if (priv == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ priv->hw.init = &init;
+ priv->i2c_dev = i2c_dev;
+
+ clk_hw_register_clkdev(&priv->hw, "div", dev_name(dev));
+ return devm_clk_register(dev, &priv->hw);
}
static void bcm2835_fill_txfifo(struct bcm2835_i2c_dev *i2c_dev)
@@ -279,7 +347,7 @@
{
struct bcm2835_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
unsigned long time_left;
- int i, ret;
+ int i;
for (i = 0; i < (num - 1); i++)
if (msgs[i].flags & I2C_M_RD) {
@@ -287,10 +355,6 @@
"only one read message supported, has to be last\n");
return -EOPNOTSUPP;
}
-
- ret = bcm2835_i2c_set_divider(i2c_dev);
- if (ret)
- return ret;
i2c_dev->curr_msg = msgs;
i2c_dev->num_msgs = num;
@@ -332,8 +396,8 @@
};
/*
- * This HW was reported to have problems with clock stretching:
- * http://www.advamation.com/knowhow/raspberrypi/rpi-i2c-bug.html
+ * The BCM2835 was reported to have problems with clock stretching:
+ * https://www.advamation.com/knowhow/raspberrypi/rpi-i2c-bug.html
* https://www.raspberrypi.org/forums/viewtopic.php?p=146272
*/
static const struct i2c_adapter_quirks bcm2835_i2c_quirks = {
@@ -346,6 +410,8 @@
struct resource *mem, *irq;
int ret;
struct i2c_adapter *adap;
+ struct clk *mclk;
+ u32 bus_clk_rate;
i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
if (!i2c_dev)
@@ -359,19 +425,36 @@
if (IS_ERR(i2c_dev->regs))
return PTR_ERR(i2c_dev->regs);
- i2c_dev->clk = devm_clk_get(&pdev->dev, NULL);
- if (IS_ERR(i2c_dev->clk)) {
- if (PTR_ERR(i2c_dev->clk) != -EPROBE_DEFER)
- dev_err(&pdev->dev, "Could not get clock\n");
- return PTR_ERR(i2c_dev->clk);
+ mclk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(mclk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(mclk),
+ "Could not get clock\n");
+
+ i2c_dev->bus_clk = bcm2835_i2c_register_div(&pdev->dev, mclk, i2c_dev);
+
+ if (IS_ERR(i2c_dev->bus_clk)) {
+ dev_err(&pdev->dev, "Could not register clock\n");
+ return PTR_ERR(i2c_dev->bus_clk);
}
ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
- &i2c_dev->bus_clk_rate);
+ &bus_clk_rate);
if (ret < 0) {
dev_warn(&pdev->dev,
"Could not read clock-frequency property\n");
- i2c_dev->bus_clk_rate = 100000;
+ bus_clk_rate = I2C_MAX_STANDARD_MODE_FREQ;
+ }
+
+ ret = clk_set_rate_exclusive(i2c_dev->bus_clk, bus_clk_rate);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Could not set clock frequency\n");
+ return ret;
+ }
+
+ ret = clk_prepare_enable(i2c_dev->bus_clk);
+ if (ret) {
+ dev_err(&pdev->dev, "Couldn't prepare clock");
+ return ret;
}
irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
@@ -392,12 +475,19 @@
i2c_set_adapdata(adap, i2c_dev);
adap->owner = THIS_MODULE;
adap->class = I2C_CLASS_DEPRECATED;
- strlcpy(adap->name, "bcm2835 I2C adapter", sizeof(adap->name));
+ snprintf(adap->name, sizeof(adap->name), "bcm2835 (%s)",
+ of_node_full_name(pdev->dev.of_node));
adap->algo = &bcm2835_i2c_algo;
adap->dev.parent = &pdev->dev;
adap->dev.of_node = pdev->dev.of_node;
- adap->quirks = &bcm2835_i2c_quirks;
+ adap->quirks = of_device_get_match_data(&pdev->dev);
+ /*
+ * Disable the hardware clock stretching timeout. SMBUS
+ * specifies a limit for how long the device can stretch the
+ * clock, but core I2C doesn't.
+ */
+ bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_CLKT, 0);
bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_C, 0);
ret = i2c_add_adapter(adap);
@@ -411,6 +501,9 @@
{
struct bcm2835_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
+ clk_rate_exclusive_put(i2c_dev->bus_clk);
+ clk_disable_unprepare(i2c_dev->bus_clk);
+
free_irq(i2c_dev->irq, i2c_dev);
i2c_del_adapter(&i2c_dev->adapter);
@@ -418,7 +511,8 @@
}
static const struct of_device_id bcm2835_i2c_of_match[] = {
- { .compatible = "brcm,bcm2835-i2c" },
+ { .compatible = "brcm,bcm2711-i2c" },
+ { .compatible = "brcm,bcm2835-i2c", .data = &bcm2835_i2c_quirks },
{},
};
MODULE_DEVICE_TABLE(of, bcm2835_i2c_of_match);
--
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