From ad115623449a3e80d89b725f833b885a9ad29c33 Mon Sep 17 00:00:00 2001
From: Federico Vaga <federico.vaga@cern.ch>
Date: Tue, 17 Mar 2020 11:13:35 +0100
Subject: [PATCH] sw:i2c: add support for kernel greater than 4.7
Instead of check for version here and there, the main code always uses
the latest API, and in a preprocessor ``if`` statement I implemented
the compatibility layer.
Like this it will be easier to apply patches from the kernel to our
local driver
Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
---
CHANGELOG.rst | 1 +
.../drivers/i2c/busses/i2c-ocores.c | 167 +++++++++++++-----
2 files changed, 128 insertions(+), 40 deletions(-)
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 8b26d4eb..2af56bfc 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -14,6 +14,7 @@ Versioning: `Semantic Versioning <https://semver.org/spec/v2.0.0.html>`_
Added
-----
- [hdl] VHDL functions to convert characters and strings to upper/lower case.
+- [sw][i2c] support for kernel greater than 4.7
Changed
-------
- [hdl] Rewritten the WB master interface used in simulations.
diff --git a/software/i2c-ocores/drivers/i2c/busses/i2c-ocores.c b/software/i2c-ocores/drivers/i2c/busses/i2c-ocores.c
index b7a458d6..12465de3 100644
--- a/software/i2c-ocores/drivers/i2c/busses/i2c-ocores.c
+++ b/software/i2c-ocores/drivers/i2c/busses/i2c-ocores.c
@@ -28,6 +28,91 @@
#include <linux/spinlock.h>
#include <linux/jiffies.h>
+struct ocores_i2c;
+static int ohwr_i2c_mux_select(struct ocores_i2c *i2c, u32 num);
+static int ohwr_i2c_mux_deselect(struct ocores_i2c *i2c, u32 num);
+
+#if KERNEL_VERSION(4, 7, 0) > LINUX_VERSION_CODE
+struct i2c_mux_core {
+ struct i2c_adapter *parent;
+ struct device *dev;
+ void *priv;
+
+ unsigned int max_adapters;
+ struct i2c_adapter *adapter[0];
+};
+
+/**
+ * It selects the I2C bus to use and lock it
+ */
+static int ocores_i2c_mux_select_old_api(struct i2c_adapter *adap,
+ void *priv, u32 num)
+{
+ struct ocores_i2c *i2c = priv;
+
+ return ohwr_i2c_mux_select(i2c, num);
+}
+
+/**
+ * It unlocks the bus so that it can be changed.
+ */
+static int ocores_i2c_mux_deselect_old_api(struct i2c_adapter *adap,
+ void *priv, u32 num)
+{
+ struct ocores_i2c *i2c = priv;
+
+ return ohwr_i2c_mux_deselect(i2c, num);
+}
+
+struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent,
+ struct device *dev, int max_adapters,
+ int sizeof_priv, u32 flags,
+ int (*select)(struct i2c_mux_core *, u32),
+ int (*deselect)(struct i2c_mux_core *, u32))
+{
+ struct i2c_mux_core *muxc;
+
+ muxc = devm_kzalloc(dev, sizeof(*muxc) +
+ sizeof(*muxc->adapter) * max_adapters +
+ sizeof_priv, GFP_KERNEL);
+ if (!muxc)
+ return NULL;
+ if (sizeof_priv)
+ muxc->priv = &muxc->adapter[max_adapters];
+ muxc->parent = parent;
+ muxc->dev = dev;
+ muxc->max_adapters = max_adapters;
+
+ return muxc;
+}
+
+int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
+ u32 force_nr, u32 chan_id,
+ unsigned int class)
+{
+ muxc->adapter[chan_id] = i2c_add_mux_adapter(muxc->parent,
+ muxc->dev,
+ muxc->priv,
+ force_nr,
+ chan_id,
+#if KERNEL_VERSION(3, 7, 0) <= LINUX_VERSION_CODE
+ class, /* class */
+#endif
+ ocores_i2c_mux_select_old_api,
+ ocores_i2c_mux_deselect_old_api);
+ return muxc->adapter[chan_id] ? 0 : -EINVAL;
+}
+
+void i2c_mux_del_adapters(struct i2c_mux_core *muxc)
+{
+ int i;
+
+ for (i = 0; i < muxc->max_adapters; ++i)
+ i2c_del_mux_adapter(muxc->adapter[i]);
+}
+#endif
+
+
#define OCORES_FLAG_POLL BIT(0)
/**
@@ -41,8 +126,7 @@ struct ocores_i2c {
unsigned long flags;
wait_queue_head_t wait;
struct i2c_adapter adap;
- struct i2c_adapter **adap_mux;
- unsigned int n_adap_mux;
+ struct i2c_mux_core *adap_mux;
struct i2c_msg *msg;
int pos;
int nmsgs;
@@ -578,14 +662,8 @@ static const struct platform_device_id ocores_id_table[] = {
};
MODULE_DEVICE_TABLE(id_table, ocores_id_table);
-
-/**
- * It selects the I2C bus to use and lock it
- */
-static int ocores_i2c_mux_select(struct i2c_adapter *adap,
- void *priv, u32 num)
+static int ohwr_i2c_mux_select(struct ocores_i2c *i2c, u32 num)
{
- struct ocores_i2c *i2c = priv;
u8 mux;
mux = oc_getreg(i2c, OCI2C_OHWR_MUX);
@@ -601,57 +679,69 @@ static int ocores_i2c_mux_select(struct i2c_adapter *adap,
return 0;
}
-
-/**
- * It unlocks the bus so that it can be changed.
- */
-static int ocores_i2c_mux_deselect(struct i2c_adapter *adap,
- void *priv, u32 num)
+static int ohwr_i2c_mux_deselect(struct ocores_i2c *i2c, u32 num)
{
- struct ocores_i2c *i2c = priv;
u8 mux;
/* Unlock bus selection */
mux = oc_getreg(i2c, OCI2C_OHWR_MUX);
if (unlikely(!(mux & OCI2C_OHWR_MUX_BUSY)))
- dev_err(&adap->dev, "deselect a bus that was not selected\n");
+ dev_err(i2c->adap_mux->dev,
+ "deselect a bus that was not selected\n");
mux &= ~OCI2C_OHWR_MUX_BUSY;
oc_setreg(i2c, OCI2C_OHWR_MUX, mux);
return 0;
}
+/**
+ * It selects the I2C bus to use and lock it
+ */
+static int ocores_i2c_mux_select(struct i2c_mux_core *muxc, u32 num)
+{
+ struct ocores_i2c *i2c = muxc->priv;
+
+ return ohwr_i2c_mux_select(i2c, num);
+}
+
+/**
+ * It unlocks the bus so that it can be changed.
+ */
+static int ocores_i2c_mux_deselect(struct i2c_mux_core *muxc, u32 num)
+{
+ struct ocores_i2c *i2c = muxc->priv;
+
+ return ohwr_i2c_mux_deselect(i2c, num);
+}
/**
* Add OHWR multiplexer
*/
static int ocores_i2c_probe_ohwr(struct ocores_i2c *i2c)
{
- int err, i;
-
- i2c->n_adap_mux = 2;
- i2c->adap_mux = devm_kzalloc(&i2c->adap.dev,
- sizeof(void *) * i2c->n_adap_mux,
- GFP_KERNEL);
- for (i = 0; i < i2c->n_adap_mux; ++i) {
- i2c->adap_mux[i] = i2c_add_mux_adapter(&i2c->adap,
- i2c->adap.dev.parent,
- i2c,
- 0, i,
-#if KERNEL_VERSION(3, 7, 0) <= LINUX_VERSION_CODE
- 0, /* class */
-#endif
- ocores_i2c_mux_select,
- ocores_i2c_mux_deselect);
- if (!i2c->adap_mux[i])
+ int i, err = 0;
+
+ i2c->adap_mux = i2c_mux_alloc(&i2c->adap, i2c->adap.dev.parent,
+ 2, sizeof(i2c), 0,
+ ocores_i2c_mux_select,
+ ocores_i2c_mux_deselect);
+ if (!i2c->adap_mux) {
+ err = -ENOMEM;
+ goto err_exit;
+ }
+ i2c->adap_mux->priv = i2c;
+ for (i = 0; i < i2c->adap_mux->max_adapters; ++i) {
+ err = i2c_mux_add_adapter(i2c->adap_mux,
+ 0, i, 0);
+ if (err)
goto err_add;
}
return 0;
err_add:
- while (--i >= 0)
- i2c_del_mux_adapter(i2c->adap_mux[i]);
+ i2c_mux_del_adapters(i2c->adap_mux);
+err_exit:
return err;
}
@@ -660,10 +750,7 @@ err_add:
*/
static void ocores_i2c_remove_ohwr(struct ocores_i2c *i2c)
{
- int i;
-
- for (i = 0; i < i2c->n_adap_mux; ++i)
- i2c_del_mux_adapter(i2c->adap_mux[i]);
+ i2c_mux_del_adapters(i2c->adap_mux);
}
#ifdef CONFIG_OF
--
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