diff mbox series

[v2,3/5] lib: utils/i2c: Add simple FDT based I2C framework

Message ID 20211015131925.22585-4-nikita.shubin@maquefel.me
State Superseded
Headers show
Series I2C framework, reboot Unmatched via PMIC | expand

Commit Message

Nikita Shubin Oct. 15, 2021, 1:19 p.m. UTC 
From: Nikita Shubin <n.shubin@yadro.com>

FDT based I2C framework on the top of I2C library.

The drivers are probed on demand by fdt_i2c_adapter_get
function.

Signed-off-by: Nikita Shubin <n.shubin@yadro.com>
---
 include/sbi_utils/i2c/fdt_i2c.h |  26 ++++++++
 lib/utils/i2c/fdt_i2c.c         | 108 ++++++++++++++++++++++++++++++++
 lib/utils/i2c/objects.mk        |   1 +
 3 files changed, 135 insertions(+)
 create mode 100644 include/sbi_utils/i2c/fdt_i2c.h
 create mode 100644 lib/utils/i2c/fdt_i2c.c

Comments

Alexandre Ghiti Oct. 19, 2021, 12:05 p.m. UTC | #1 
On Fri, Oct 15, 2021 at 3:20 PM Nikita Shubin <nikita.shubin@maquefel.me> wrote:
>
> From: Nikita Shubin <n.shubin@yadro.com>
>
> FDT based I2C framework on the top of I2C library.
>
> The drivers are probed on demand by fdt_i2c_adapter_get
> function.
>
> Signed-off-by: Nikita Shubin <n.shubin@yadro.com>
> ---
>  include/sbi_utils/i2c/fdt_i2c.h |  26 ++++++++
>  lib/utils/i2c/fdt_i2c.c         | 108 ++++++++++++++++++++++++++++++++
>  lib/utils/i2c/objects.mk        |   1 +
>  3 files changed, 135 insertions(+)
>  create mode 100644 include/sbi_utils/i2c/fdt_i2c.h
>  create mode 100644 lib/utils/i2c/fdt_i2c.c
>
> diff --git a/include/sbi_utils/i2c/fdt_i2c.h b/include/sbi_utils/i2c/fdt_i2c.h
> new file mode 100644
> index 0000000..1f41a0f
> --- /dev/null
> +++ b/include/sbi_utils/i2c/fdt_i2c.h
> @@ -0,0 +1,26 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2021 YADRO
> + *
> + * Authors:
> + *   Nikita Shubin <nshubin@yadro.com>
> + */
> +
> +#ifndef __FDT_I2C_H__
> +#define __FDT_I2C_H__
> +
> +#include <sbi_utils/i2c/i2c.h>
> +
> +/** FDT based I2C adapter driver */
> +struct fdt_i2c_adapter {
> +       const struct fdt_match *match_table;
> +       int (*init)(void *fdt, int nodeoff,
> +                   const struct fdt_match *match);
> +};
> +
> +/** Get I2C adapter identified by nodeoff */
> +int fdt_i2c_adapter_get(void *fdt, int nodeoff,
> +                       struct i2c_adapter **out_adapter);
> +
> +#endif
> diff --git a/lib/utils/i2c/fdt_i2c.c b/lib/utils/i2c/fdt_i2c.c
> new file mode 100644
> index 0000000..fce6d73
> --- /dev/null
> +++ b/lib/utils/i2c/fdt_i2c.c
> @@ -0,0 +1,108 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2021 YADRO
> + *
> + * Authors:
> + *   Nikita Shubin <nshubin@yadro.com>
> + *
> + * derivate: lib/utils/gpio/fdt_gpio.c
> + * Authors:
> + *   Anup Patel <anup.patel@wdc.com>
> + */
> +
> +#include <libfdt.h>
> +#include <sbi/sbi_error.h>
> +#include <sbi_utils/fdt/fdt_helper.h>
> +#include <sbi_utils/i2c/fdt_i2c.h>
> +
> +#include <sbi/sbi_console.h>
> +
> +static struct fdt_i2c_adapter *i2c_adapter_drivers[] = {
> +};
> +
> +static struct fdt_i2c_adapter
> +       *fdt_i2c_adapter_driver(struct i2c_adapter *adapter)
> +{
> +       int pos;
> +
> +       if (!adapter)
> +               return NULL;
> +
> +       for (pos = 0; pos < array_size(i2c_adapter_drivers); pos++) {
> +               if (adapter->driver == i2c_adapter_drivers[pos])
> +                       return i2c_adapter_drivers[pos];
> +       }
> +
> +       return NULL;
> +}

I don't see the point of this function since it simply returns
adapter->driver right?

> +
> +static int fdt_i2c_adapter_init(void *fdt, int nodeoff)
> +{
> +       int pos, rc;
> +       struct fdt_i2c_adapter *drv;
> +       const struct fdt_match *match;
> +
> +       /* Try all I2C drivers one-by-one */
> +       for (pos = 0; pos < array_size(i2c_adapter_drivers); pos++) {
> +               drv = i2c_adapter_drivers[pos];
> +               match = fdt_match_node(fdt, nodeoff, drv->match_table);
> +               if (match && drv->init) {
> +                       rc = drv->init(fdt, nodeoff, match);
> +                       if (rc == SBI_ENODEV)
> +                               continue;
> +                       if (rc)
> +                               return rc;
> +                       return 0;
> +               }
> +       }
> +
> +       return SBI_ENOSYS;
> +}
> +
> +static int fdt_i2c_adapter_find(void *fdt, int nodeoff,
> +                               struct i2c_adapter **out_adapter)
> +{
> +       int rc;
> +       struct i2c_adapter *adapter = i2c_adapter_find(nodeoff);
> +
> +       if (!adapter) {
> +               /* I2C adapter not found so initialize matching driver */
> +               rc = fdt_i2c_adapter_init(fdt, nodeoff);
> +               if (rc)
> +                       return rc;
> +
> +               /* Try to find I2C adapter again */
> +               adapter = i2c_adapter_find(nodeoff);
> +               if (!adapter)
> +                       return SBI_ENOSYS;
> +       }
> +
> +       if (out_adapter)
> +               *out_adapter = adapter;
> +
> +       return 0;
> +}
> +
> +int fdt_i2c_adapter_get(void *fdt, int nodeoff,
> +                       struct i2c_adapter **out_adapter)
> +{
> +       int rc;
> +       struct i2c_adapter *adapter;
> +       struct fdt_i2c_adapter *drv;
> +
> +       if (!fdt || (nodeoff < 0) || !out_adapter)
> +               return SBI_EINVAL;
> +
> +       rc = fdt_i2c_adapter_find(fdt, nodeoff, &adapter);
> +       if (rc)
> +               return rc;
> +
> +       drv = fdt_i2c_adapter_driver(adapter);
> +       if (!drv)
> +               return SBI_ENOSYS;
> +
> +       *out_adapter = adapter;
> +
> +       return 0;
> +}
> diff --git a/lib/utils/i2c/objects.mk b/lib/utils/i2c/objects.mk
> index 16a70da..06baa65 100644
> --- a/lib/utils/i2c/objects.mk
> +++ b/lib/utils/i2c/objects.mk
> @@ -8,3 +8,4 @@
>  #
>
>  libsbiutils-objs-y += i2c/i2c.o
> +libsbiutils-objs-y += i2c/fdt_i2c.o
> --
> 2.31.1
>
>
> --
> opensbi mailing list
> opensbi@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/opensbi
Nikita Shubin Oct. 20, 2021, 6:49 a.m. UTC | #2 
Hello Alexandre!

On Tue, 19 Oct 2021 14:05:58 +0200
Alexandre Ghiti <alexandre.ghiti@canonical.com> wrote:

> On Fri, Oct 15, 2021 at 3:20 PM Nikita Shubin
> <nikita.shubin@maquefel.me> wrote:
> >
> > From: Nikita Shubin <n.shubin@yadro.com>
> >
> > FDT based I2C framework on the top of I2C library.
> >
> > The drivers are probed on demand by fdt_i2c_adapter_get
> > function.
> >
> > Signed-off-by: Nikita Shubin <n.shubin@yadro.com>
> > ---
> >  include/sbi_utils/i2c/fdt_i2c.h |  26 ++++++++
> >  lib/utils/i2c/fdt_i2c.c         | 108
> > ++++++++++++++++++++++++++++++++ lib/utils/i2c/objects.mk        |
> >  1 + 3 files changed, 135 insertions(+)
> >  create mode 100644 include/sbi_utils/i2c/fdt_i2c.h
> >  create mode 100644 lib/utils/i2c/fdt_i2c.c
> >
> > diff --git a/include/sbi_utils/i2c/fdt_i2c.h
> > b/include/sbi_utils/i2c/fdt_i2c.h new file mode 100644
> > index 0000000..1f41a0f
> > --- /dev/null
> > +++ b/include/sbi_utils/i2c/fdt_i2c.h
> > @@ -0,0 +1,26 @@
> > +/*
> > + * SPDX-License-Identifier: BSD-2-Clause
> > + *
> > + * Copyright (c) 2021 YADRO
> > + *
> > + * Authors:
> > + *   Nikita Shubin <nshubin@yadro.com>
> > + */
> > +
> > +#ifndef __FDT_I2C_H__
> > +#define __FDT_I2C_H__
> > +
> > +#include <sbi_utils/i2c/i2c.h>
> > +
> > +/** FDT based I2C adapter driver */
> > +struct fdt_i2c_adapter {
> > +       const struct fdt_match *match_table;
> > +       int (*init)(void *fdt, int nodeoff,
> > +                   const struct fdt_match *match);
> > +};
> > +
> > +/** Get I2C adapter identified by nodeoff */
> > +int fdt_i2c_adapter_get(void *fdt, int nodeoff,
> > +                       struct i2c_adapter **out_adapter);
> > +
> > +#endif
> > diff --git a/lib/utils/i2c/fdt_i2c.c b/lib/utils/i2c/fdt_i2c.c
> > new file mode 100644
> > index 0000000..fce6d73
> > --- /dev/null
> > +++ b/lib/utils/i2c/fdt_i2c.c
> > @@ -0,0 +1,108 @@
> > +/*
> > + * SPDX-License-Identifier: BSD-2-Clause
> > + *
> > + * Copyright (c) 2021 YADRO
> > + *
> > + * Authors:
> > + *   Nikita Shubin <nshubin@yadro.com>
> > + *
> > + * derivate: lib/utils/gpio/fdt_gpio.c
> > + * Authors:
> > + *   Anup Patel <anup.patel@wdc.com>
> > + */
> > +
> > +#include <libfdt.h>
> > +#include <sbi/sbi_error.h>
> > +#include <sbi_utils/fdt/fdt_helper.h>
> > +#include <sbi_utils/i2c/fdt_i2c.h>
> > +
> > +#include <sbi/sbi_console.h>
> > +
> > +static struct fdt_i2c_adapter *i2c_adapter_drivers[] = {
> > +};
> > +
> > +static struct fdt_i2c_adapter
> > +       *fdt_i2c_adapter_driver(struct i2c_adapter *adapter)
> > +{
> > +       int pos;
> > +
> > +       if (!adapter)
> > +               return NULL;
> > +
> > +       for (pos = 0; pos < array_size(i2c_adapter_drivers); pos++)
> > {
> > +               if (adapter->driver == i2c_adapter_drivers[pos])
> > +                       return i2c_adapter_drivers[pos];
> > +       }
> > +
> > +       return NULL;
> > +}  
> 
> I don't see the point of this function since it simply returns
> adapter->driver right?

It looks like you are right. This can be ommited as well as 
fdt_i2c_adapter_driver check in fdt_i2c_adapter_get.

> 
> > +
> > +static int fdt_i2c_adapter_init(void *fdt, int nodeoff)
> > +{
> > +       int pos, rc;
> > +       struct fdt_i2c_adapter *drv;
> > +       const struct fdt_match *match;
> > +
> > +       /* Try all I2C drivers one-by-one */
> > +       for (pos = 0; pos < array_size(i2c_adapter_drivers); pos++)
> > {
> > +               drv = i2c_adapter_drivers[pos];
> > +               match = fdt_match_node(fdt, nodeoff,
> > drv->match_table);
> > +               if (match && drv->init) {
> > +                       rc = drv->init(fdt, nodeoff, match);
> > +                       if (rc == SBI_ENODEV)
> > +                               continue;
> > +                       if (rc)
> > +                               return rc;
> > +                       return 0;
> > +               }
> > +       }
> > +
> > +       return SBI_ENOSYS;
> > +}
> > +
> > +static int fdt_i2c_adapter_find(void *fdt, int nodeoff,
> > +                               struct i2c_adapter **out_adapter)
> > +{
> > +       int rc;
> > +       struct i2c_adapter *adapter = i2c_adapter_find(nodeoff);
> > +
> > +       if (!adapter) {
> > +               /* I2C adapter not found so initialize matching
> > driver */
> > +               rc = fdt_i2c_adapter_init(fdt, nodeoff);
> > +               if (rc)
> > +                       return rc;
> > +
> > +               /* Try to find I2C adapter again */
> > +               adapter = i2c_adapter_find(nodeoff);
> > +               if (!adapter)
> > +                       return SBI_ENOSYS;
> > +       }
> > +
> > +       if (out_adapter)
> > +               *out_adapter = adapter;
> > +
> > +       return 0;
> > +}
> > +
> > +int fdt_i2c_adapter_get(void *fdt, int nodeoff,
> > +                       struct i2c_adapter **out_adapter)
> > +{
> > +       int rc;
> > +       struct i2c_adapter *adapter;
> > +       struct fdt_i2c_adapter *drv;
> > +
> > +       if (!fdt || (nodeoff < 0) || !out_adapter)
> > +               return SBI_EINVAL;
> > +
> > +       rc = fdt_i2c_adapter_find(fdt, nodeoff, &adapter);
> > +       if (rc)
> > +               return rc;
> > +
> > +       drv = fdt_i2c_adapter_driver(adapter);
> > +       if (!drv)
> > +               return SBI_ENOSYS;
> > +
> > +       *out_adapter = adapter;
> > +
> > +       return 0;
> > +}
> > diff --git a/lib/utils/i2c/objects.mk b/lib/utils/i2c/objects.mk
> > index 16a70da..06baa65 100644
> > --- a/lib/utils/i2c/objects.mk
> > +++ b/lib/utils/i2c/objects.mk
> > @@ -8,3 +8,4 @@
> >  #
> >
> >  libsbiutils-objs-y += i2c/i2c.o
> > +libsbiutils-objs-y += i2c/fdt_i2c.o
> > --
> > 2.31.1
> >
> >
> > --
> > opensbi mailing list
> > opensbi@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/opensbi
diff mbox series

Patch

diff --git a/include/sbi_utils/i2c/fdt_i2c.h b/include/sbi_utils/i2c/fdt_i2c.h
new file mode 100644
index 0000000..1f41a0f
--- /dev/null
+++ b/include/sbi_utils/i2c/fdt_i2c.h
@@ -0,0 +1,26 @@ 
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2021 YADRO
+ *
+ * Authors:
+ *   Nikita Shubin <nshubin@yadro.com>
+ */
+
+#ifndef __FDT_I2C_H__
+#define __FDT_I2C_H__
+
+#include <sbi_utils/i2c/i2c.h>
+
+/** FDT based I2C adapter driver */
+struct fdt_i2c_adapter {
+	const struct fdt_match *match_table;
+	int (*init)(void *fdt, int nodeoff,
+		    const struct fdt_match *match);
+};
+
+/** Get I2C adapter identified by nodeoff */
+int fdt_i2c_adapter_get(void *fdt, int nodeoff,
+			struct i2c_adapter **out_adapter);
+
+#endif
diff --git a/lib/utils/i2c/fdt_i2c.c b/lib/utils/i2c/fdt_i2c.c
new file mode 100644
index 0000000..fce6d73
--- /dev/null
+++ b/lib/utils/i2c/fdt_i2c.c
@@ -0,0 +1,108 @@ 
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2021 YADRO
+ *
+ * Authors:
+ *   Nikita Shubin <nshubin@yadro.com>
+ *
+ * derivate: lib/utils/gpio/fdt_gpio.c
+ * Authors:
+ *   Anup Patel <anup.patel@wdc.com>
+ */
+
+#include <libfdt.h>
+#include <sbi/sbi_error.h>
+#include <sbi_utils/fdt/fdt_helper.h>
+#include <sbi_utils/i2c/fdt_i2c.h>
+
+#include <sbi/sbi_console.h>
+
+static struct fdt_i2c_adapter *i2c_adapter_drivers[] = {
+};
+
+static struct fdt_i2c_adapter
+	*fdt_i2c_adapter_driver(struct i2c_adapter *adapter)
+{
+	int pos;
+
+	if (!adapter)
+		return NULL;
+
+	for (pos = 0; pos < array_size(i2c_adapter_drivers); pos++) {
+		if (adapter->driver == i2c_adapter_drivers[pos])
+			return i2c_adapter_drivers[pos];
+	}
+
+	return NULL;
+}
+
+static int fdt_i2c_adapter_init(void *fdt, int nodeoff)
+{
+	int pos, rc;
+	struct fdt_i2c_adapter *drv;
+	const struct fdt_match *match;
+
+	/* Try all I2C drivers one-by-one */
+	for (pos = 0; pos < array_size(i2c_adapter_drivers); pos++) {
+		drv = i2c_adapter_drivers[pos];
+		match = fdt_match_node(fdt, nodeoff, drv->match_table);
+		if (match && drv->init) {
+			rc = drv->init(fdt, nodeoff, match);
+			if (rc == SBI_ENODEV)
+				continue;
+			if (rc)
+				return rc;
+			return 0;
+		}
+	}
+
+	return SBI_ENOSYS;
+}
+
+static int fdt_i2c_adapter_find(void *fdt, int nodeoff,
+				struct i2c_adapter **out_adapter)
+{
+	int rc;
+	struct i2c_adapter *adapter = i2c_adapter_find(nodeoff);
+
+	if (!adapter) {
+		/* I2C adapter not found so initialize matching driver */
+		rc = fdt_i2c_adapter_init(fdt, nodeoff);
+		if (rc)
+			return rc;
+
+		/* Try to find I2C adapter again */
+		adapter = i2c_adapter_find(nodeoff);
+		if (!adapter)
+			return SBI_ENOSYS;
+	}
+
+	if (out_adapter)
+		*out_adapter = adapter;
+
+	return 0;
+}
+
+int fdt_i2c_adapter_get(void *fdt, int nodeoff,
+			struct i2c_adapter **out_adapter)
+{
+	int rc;
+	struct i2c_adapter *adapter;
+	struct fdt_i2c_adapter *drv;
+
+	if (!fdt || (nodeoff < 0) || !out_adapter)
+		return SBI_EINVAL;
+
+	rc = fdt_i2c_adapter_find(fdt, nodeoff, &adapter);
+	if (rc)
+		return rc;
+
+	drv = fdt_i2c_adapter_driver(adapter);
+	if (!drv)
+		return SBI_ENOSYS;
+
+	*out_adapter = adapter;
+
+	return 0;
+}
diff --git a/lib/utils/i2c/objects.mk b/lib/utils/i2c/objects.mk
index 16a70da..06baa65 100644
--- a/lib/utils/i2c/objects.mk
+++ b/lib/utils/i2c/objects.mk
@@ -8,3 +8,4 @@ 
 #
 
 libsbiutils-objs-y += i2c/i2c.o
+libsbiutils-objs-y += i2c/fdt_i2c.o