[U-Boot] [PATCH v1 10/16] drivers: Add SPMI bus uclass

Mateusz Kulikowski
2016-01-06T18:21:22Z

Qualcom processors use proprietary bus to talk with PMIC devices -
SPMI (System Power Management Interface).

On wiring level it is similar to I2C, but on protocol level, it's
multi-master and has simple autodetection capabilities.
This commit adds simple uclass that provides bus read/write interface.

Signed-off-by: Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
---

Changes in v1:
- Reorder includes
- Add read/write arguments documentation

drivers/Kconfig | 2 ++
drivers/Makefile | 1 +
drivers/spmi/Kconfig | 10 ++++++++++
drivers/spmi/Makefile | 7 +++++++
drivers/spmi/spmi-uclass.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++
include/dm/uclass-id.h | 1 +
include/spmi/spmi.h | 47 +++++++++++++++++++++++++++++++++++++++++++++
7 files changed, 116 insertions(+)
create mode 100644 drivers/spmi/Kconfig
create mode 100644 drivers/spmi/Makefile
create mode 100644 drivers/spmi/spmi-uclass.c
create mode 100644 include/spmi/spmi.h

diff --git a/drivers/Kconfig b/drivers/Kconfig
index c481e93..4cbe976 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -52,6 +52,8 @@ source "drivers/remoteproc/Kconfig"

source "drivers/rtc/Kconfig"

+source "drivers/spmi/Kconfig"
+
source "drivers/serial/Kconfig"

source "drivers/sound/Kconfig"
diff --git a/drivers/Makefile b/drivers/Makefile
index c9031f2..7ae72c0 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -53,6 +53,7 @@ obj-y += pcmcia/
obj-y += dfu/
obj-y += rtc/
obj-y += sound/
+obj-y += spmi/
obj-y += timer/
obj-y += tpm/
obj-y += twserial/
diff --git a/drivers/spmi/Kconfig b/drivers/spmi/Kconfig
new file mode 100644
index 0000000..440431a
--- /dev/null
+++ b/drivers/spmi/Kconfig
@@ -0,0 +1,10 @@
+menu "SPMI support"
+
+config DM_SPMI
+ bool "Enable SPMI bus support"
+ depends on DM
+ ---help---
+ Select this to enable to support SPMI bus.
+ SPMI (System Power Management Interface) bus is used
+ to connect PMIC devices on various SoCs.
+endmenu
diff --git a/drivers/spmi/Makefile b/drivers/spmi/Makefile
new file mode 100644
index 0000000..2015b1a
--- /dev/null
+++ b/drivers/spmi/Makefile
@@ -0,0 +1,7 @@
+#
+# (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
+#
+# SPDX-License-Identifier: GPL-2.0+
+#
+
+obj-$(CONFIG_DM_SPMI) += spmi-uclass.o
diff --git a/drivers/spmi/spmi-uclass.c b/drivers/spmi/spmi-uclass.c
new file mode 100644
index 0000000..7d5429a
--- /dev/null
+++ b/drivers/spmi/spmi-uclass.c
@@ -0,0 +1,48 @@
+/*
+ * SPMI bus uclass driver
+ *
+ * (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/root.h>
+#include <errno.h>
+#include <spmi/spmi.h>
+#include <linux/ctype.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int spmi_reg_read(struct udevice *dev, int usid, int pid, int reg)
+{
+ const struct dm_spmi_ops *ops = dev_get_driver_ops(dev);
+
+ if (!ops || !ops->read)
+ return -ENOSYS;
+
+ return ops->read(dev, usid, pid, reg);
+}
+
+int spmi_reg_write(struct udevice *dev, int usid, int pid, int reg,
+ uint8_t value)
+{
+ const struct dm_spmi_ops *ops = dev_get_driver_ops(dev);
+
+ if (!ops || !ops->write)
+ return -ENOSYS;
+
+ return ops->write(dev, usid, pid, reg, value);
+}
+
+static int spmi_post_bind(struct udevice *dev)
+{
+ return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false);
+}
+
+UCLASS_DRIVER(spmi) = {
+ .id = UCLASS_SPMI,
+ .name = "spmi",
+ .post_bind = spmi_post_bind,
+};
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 27fa0b6..772e780 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -57,6 +57,7 @@ enum uclass_id {
UCLASS_RTC, /* Real time clock device */
UCLASS_SERIAL, /* Serial UART */
UCLASS_SPI, /* SPI bus */
+ UCLASS_SPMI, /* System Power Management Interface bus */
UCLASS_SPI_FLASH, /* SPI flash */
UCLASS_SPI_GENERIC, /* Generic SPI flash target */
UCLASS_SYSCON, /* System configuration device */
diff --git a/include/spmi/spmi.h b/include/spmi/spmi.h
new file mode 100644
index 0000000..65a49bd
--- /dev/null
+++ b/include/spmi/spmi.h
@@ -0,0 +1,47 @@
+#ifndef _SPMI_SPMI_H
+#define _SPMI_SPMI_H
+
+/**
+ * struct dm_spmi_ops - SPMI device I/O interface
+ *
+ * Should be implemented by UCLASS_SPMI device drivers. The standard
+ * device operations provides the I/O interface for it's childs.
+ *
+ * @read: read register 'reg' of slave 'usid' and peripheral 'pid'
+ * @write: write register 'reg' of slave 'usid' and peripheral 'pid'
+ *
+ * Each register is 8-bit, both read and write can return negative values
+ * on error.
+ */
+struct dm_spmi_ops {
+ int (*read)(struct udevice *dev, int usid, int pid, int reg);
+ int (*write)(struct udevice *dev, int usid, int pid, int reg,
+ uint8_t value);
+};
+
+/**
+ * spmi_reg_read() - read a register from specific slave/peripheral
+ *
+ * @dev: SPMI bus to read
+ * @usid SlaveID
+ * @pid Peripheral ID
+ * @reg: Register to read
+ * @return value read on success or negative value of errno.
+ */
+int spmi_reg_read(struct udevice *dev, int usid, int pid, int reg);
+
+/**
+ * spmi_reg_write() - write a register of specific slave/peripheral
+ *
+ * @dev: SPMI bus to write
+ * @usid SlaveID
+ * @pid Peripheral ID
+ * @reg: Register to write
+ * @value: Value to write
+ * @return 0 on success or negative value of errno.
+ */
+int spmi_reg_write(struct udevice *dev, int usid, int pid, int reg,
+ uint8_t value);
+
+#endif
+
--
2.5.0