[U-Boot] [PATCH v4 04/16] dm: pmic: add implementation of driver model pmic uclass

Przemyslaw Marczak
2015-04-20T18:07:41Z

This commit introduces the PMIC uclass implementation.
It allows providing the basic I/O interface for PMIC devices.
For the multi-function PMIC devices, this can be used as I/O
parent device, for each IC's interface. Then, each PMIC particular
function can be provided by the child device's operations, and the
child devices will use its parent for read/write by the common API.

Core files:
- 'include/power/pmic.h'
- 'drivers/power/pmic/pmic-uclass.c'

The old pmic framework is still kept and is independent.

For more detailed informations, please look into the header file.

Changes:
- new uclass-id: UCLASS_PMIC
- new config: CONFIG_DM_PMIC

Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
---
Changes V2:
- pmic uclass: adjust uclass code to the mainline changes
- pmic uclass: remove pmic_i2c and pmic_spi
- pmic uclass: modify pmic_platdata
- pmic uclass: add pmic_if_* functions
- pmic uclass: remove pmic_init_dm()
- pmic uclass: cleanup
- pmic.h: define pmic ops structure (read/write operations)
- pmic.h: add comments to functions

Changes V3:
- pmic-uclass.c and pmic.h:
-- remove pmic_if_* functions
-- add new function pmic_child_node_scan()
- add Kconfig entry

Changes V4:
- move drivers/power/pmic-uclass.c to drivers/power/pmic/pmic-uclass.c
- move DM_PMIC Kconfig entry: drivers/power/Kconfig to drivers/power/pmic/Kconfig
- drivers/power/Kconfig: Add menu "Power" and include pmic Kconfig
- Kconfig: provide only the general information about the PMIC
- pmic-uclass.c: add pmic_bind_childs()
- pmic-uclass.c: add debug
- pmic-uclass.c: cleanup includes
- pmic-uclass.c: remove pmic_get_uclass_ops() and use of dev_get_driver_ops()
- pmic-uclass.c: use of uclass_get_device_by_name()
- pmic-uclass.c: add str_get_num() - for get number from string
- include/power/pmic.h - start comments rewording
- power/pmic.h: comments update
---
drivers/power/Kconfig | 6 ++
drivers/power/pmic/Kconfig | 11 +++
drivers/power/pmic/Makefile | 1 +
drivers/power/pmic/pmic-uclass.c | 158 ++++++++++++++++++++++++++++++++
include/dm/uclass-id.h | 3 +
include/power/pmic.h | 189 +++++++++++++++++++++++++++++++++++++++
6 files changed, 368 insertions(+)
create mode 100644 drivers/power/pmic/Kconfig
create mode 100644 drivers/power/pmic/pmic-uclass.c

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index f8f0239..d03626e 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -1,3 +1,7 @@
+menu "Power"
+
+source "drivers/power/pmic/Kconfig"
+
config AXP221_POWER
boolean "axp221 / axp223 pmic support"
depends on MACH_SUN6I || MACH_SUN8I
@@ -73,3 +77,5 @@ config AXP221_ELDO3_VOLT
disable eldo3. On some A31(s) tablets it might be used to supply
1.2V for the SSD2828 chip (converter of parallel LCD interface
into MIPI DSI).
+
+endmenu
diff --git a/drivers/power/pmic/Kconfig b/drivers/power/pmic/Kconfig
new file mode 100644
index 0000000..d06d632
--- /dev/null
+++ b/drivers/power/pmic/Kconfig
@@ -0,0 +1,11 @@
+config DM_PMIC
+ bool "Enable Driver Model for PMIC drivers (UCLASS_PMIC)"
+ depends on DM
+ ---help---
+ This config enables the driver-model PMIC support.
+ UCLASS_PMIC - designed to provide an I/O interface for PMIC devices.
+ For the multi-function PMIC devices, this can be used as parent I/O
+ device for each IC's interface. Then, each children uses its parent
+ for read/write. For detailed description, please refer to the files:
+ - 'drivers/power/pmic/pmic-uclass.c'
+ - 'include/power/pmic.h'
diff --git a/drivers/power/pmic/Makefile b/drivers/power/pmic/Makefile
index 985cfdb..594f620 100644
--- a/drivers/power/pmic/Makefile
+++ b/drivers/power/pmic/Makefile
@@ -5,6 +5,7 @@
# SPDX-License-Identifier: GPL-2.0+
#

+obj-$(CONFIG_DM_PMIC) += pmic-uclass.o
obj-$(CONFIG_POWER_LTC3676) += pmic_ltc3676.o
obj-$(CONFIG_POWER_MAX8998) += pmic_max8998.o
obj-$(CONFIG_POWER_MAX8997) += pmic_max8997.o
diff --git a/drivers/power/pmic/pmic-uclass.c b/drivers/power/pmic/pmic-uclass.c
new file mode 100644
index 0000000..d82d3da
--- /dev/null
+++ b/drivers/power/pmic/pmic-uclass.c
@@ -0,0 +1,158 @@
+/*
+ * Copyright (C) 2014-2015 Samsung Electronics
+ * Przemyslaw Marczak <p.marczak@samsung.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <fdtdec.h>
+#include <errno.h>
+#include <dm.h>
+#include <dm/lists.h>
+#include <dm/device-internal.h>
+#include <dm/uclass-internal.h>
+#include <power/pmic.h>
+#include <linux/ctype.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static ulong str_get_num(const char *ptr, const char *maxptr)
+{
+ if (!ptr || !maxptr)
+ return 0;
+
+ while (!isdigit(*ptr) && ptr++ < maxptr);
+
+ return simple_strtoul(ptr, NULL, 0);
+}
+
+int pmic_bind_childs(struct udevice *pmic, int offset,
+ const struct pmic_child_info *child_info)
+{
+ const struct pmic_child_info *info;
+ const void *blob = gd->fdt_blob;
+ struct driver *drv;
+ struct udevice *child;
+ const char *node_name;
+ int node_name_len;
+ int bind_count = 0;
+ int node;
+ int prefix_len;
+ int ret;
+
+ debug("%s for '%s' at node offset: %d\n", __func__, pmic->name,
+ pmic->of_offset);
+
+ for (node = fdt_first_subnode(blob, offset);
+ node > 0;
+ node = fdt_next_subnode(blob, node)) {
+ node_name = fdt_get_name(blob, node, &node_name_len);
+
+ debug("* Found child node: '%s' at offset:%d\n", node_name,
+ node);
+
+ child = NULL;
+ info = child_info;
+ while (info->prefix) {
+ prefix_len = strlen(info->prefix);
+ if (strncasecmp(info->prefix, node_name, prefix_len) ||
+ !info->driver) {
+ info++;
+ continue;
+ }
+
+ debug(" - compatible prefix: '%s'\n", info->prefix);
+
+ drv = lists_driver_lookup_name(info->driver);
+ if (!drv) {
+ debug(" - driver: '%s' not found!\n",
+ info->driver);
+ continue;
+ }
+
+ debug(" - found child driver: '%s'\n", drv->name);
+
+ ret = device_bind(pmic, drv, node_name, NULL,
+ node, &child);
+ if (ret) {
+ debug(" - child binding error: %d\n", ret);
+ continue;
+ }
+
+ debug(" - bound child device: '%s'\n", child->name);
+
+ child->driver_data = str_get_num(node_name +
+ prefix_len,
+ node_name +
+ node_name_len);
+
+ debug(" - set 'child->driver_data': %lu\n",
+ child->driver_data);
+ break;
+ }
+
+ if (child)
+ bind_count++;
+ else
+ debug(" - compatible prefix not found\n");
+ }
+
+ debug("Bound: %d childs for PMIC: '%s'\n", bind_count, pmic->name);
+ return bind_count;
+}
+
+int pmic_get(const char *name, struct udevice **devp)
+{
+ return uclass_get_device_by_name(UCLASS_PMIC, name, devp);
+}
+
+int pmic_reg_count(struct udevice *dev)
+{
+ const struct dm_pmic_ops *ops = dev_get_driver_ops(dev);
+ if (!ops)
+ return -ENOSYS;
+
+ return ops->reg_count;
+}
+
+int pmic_read(struct udevice *dev, uint reg, uint8_t *buffer, int len)
+{
+ const struct dm_pmic_ops *ops = dev_get_driver_ops(dev);
+ int ret;
+
+ if (!buffer)
+ return -EFAULT;
+
+ if (!ops || !ops->read)
+ return -ENOSYS;
+
+ ret = ops->read(dev, reg, buffer, len);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+int pmic_write(struct udevice *dev, uint reg, const uint8_t *buffer, int len)
+{
+ const struct dm_pmic_ops *ops = dev_get_driver_ops(dev);
+ int ret;
+
+ if (!buffer)
+ return -EFAULT;
+
+ if (!ops || !ops->write)
+ return -ENOSYS;
+
+ ret = ops->write(dev, reg, buffer, len);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+UCLASS_DRIVER(pmic) = {
+ .id = UCLASS_PMIC,
+ .name = "pmic",
+};
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index fddfd35..23b3eb9 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -46,6 +46,9 @@ enum uclass_id {
UCLASS_USB_DEV_GENERIC, /* USB generic device */
UCLASS_MASS_STORAGE, /* Mass storage device */

+ /* Power Management */
+ UCLASS_PMIC, /* PMIC I/O device */
+
UCLASS_COUNT,
UCLASS_INVALID = -1,
};
diff --git a/include/power/pmic.h b/include/power/pmic.h
index afbc5aa..f7ae781 100644
--- a/include/power/pmic.h
+++ b/include/power/pmic.h
@@ -1,4 +1,7 @@
/*
+ * Copyright (C) 2014-2015 Samsung Electronics
+ * Przemyslaw Marczak <p.marczak@samsung.com>
+ *
* Copyright (C) 2011-2012 Samsung Electronics
* Lukasz Majewski <l.majewski@samsung.com>
*
@@ -9,10 +12,13 @@
#define __CORE_PMIC_H_

#include <linux/list.h>
+#include <spi.h>
#include <i2c.h>
#include <power/power_chrg.h>

enum { PMIC_I2C, PMIC_SPI, PMIC_NONE};
+
+#ifdef CONFIG_POWER
enum { I2C_PMIC, I2C_NUM, };
enum { PMIC_READ, PMIC_WRITE, };
enum { PMIC_SENSOR_BYTE_ORDER_LITTLE, PMIC_SENSOR_BYTE_ORDER_BIG, };
@@ -77,7 +83,189 @@ struct pmic {
struct pmic *parent;
struct list_head list;
};
+#endif /* CONFIG_POWER */
+
+#ifdef CONFIG_DM_PMIC
+/**
+ * U-Boot PMIC Framework
+ * =====================
+ *
+ * UCLASS_PMIC - The is designed to provide an I/O interface for PMIC devices.
+ *
+ * For the multi-function PMIC devices, this can be used as parent I/O device
+ * for each IC's interface. Then, each children uses its parent for read/write.
+ *
+ * The driver model tree could look like this:
+ *
+ *_ root device
+ * |_ BUS 0 device (e.g. I2C0) - UCLASS_I2C/SPI/...
+ * | |_ PMIC device (READ/WRITE ops) - UCLASS_PMIC
+ * | |_ REGULATOR device (ldo/buck/... ops) - UCLASS_REGULATOR
+ * | |_ CHARGER device (charger ops) - UCLASS_CHARGER (in the future)
+ * | |_ MUIC device (microUSB connector ops) - UCLASS_MUIC (in the future)
+ * | |_ ...
+ * |
+ * |_ BUS 1 device (e.g. I2C1) - UCLASS_I2C/SPI/...
+ * |_ PMIC device (READ/WRITE ops) - UCLASS_PMIC
+ * |_ RTC device (rtc ops) - UCLASS_RTC (in the future)
+ *
+ * We can find two PMIC cases in boards design:
+ * - single I/O interface
+ * - multiple I/O interfaces
+ * We bind single PMIC device for each interface, to provide an I/O as a parent,
+ * of proper child devices. Each child usually implements a different function,
+ * controlled by the same interface.
+ *
+ * The binding should be done automatically. If device tree nodes/subnodes are
+ * proper defined, then:
+ *
+ * |_ the ROOT driver will bind the device for I2C/SPI node:
+ * |_ the I2C/SPI driver should bind a device for pmic node:
+ * |_ the PMIC driver should bind devices for its childs:
+ * |_ regulator (child)
+ * |_ charger (child)
+ * |_ other (child)
+ *
+ * The same for other device nodes, for multi-interface PMIC.
+ *
+ * Note:
+ * Each PMIC interface driver should use a different compatible string.
+ *
+ * If each pmic child device driver need access the PMIC-specific registers,
+ * it need know only the register address and the access can be done through
+ * the parent pmic driver. Like in the example:
+ *
+ *_ root driver
+ * |_ dev: bus I2C0 - UCLASS_I2C
+ * | |_ dev: my_pmic (read/write) (is parent) - UCLASS_PMIC
+ * | |_ dev: my_regulator (set value/etc..) (is child) - UCLASS_REGULATOR
+ *
+ * To ensure such device relationship, the pmic device driver should also bind
+ * all its child devices, like in the example below. It should be done by call
+ * the 'pmic_bind_childs()' - please refer to the description of this function
+ * in this header file. This function, should be called in the driver's '.bind'
+ * method.
+ *
+ * For the example driver, please refer the MAX77686 driver:
+ * - 'drivers/power/pmic/max77686.c'
+ */
+
+/**
+ * struct dm_pmic_ops - PMIC device I/O interface
+ *
+ * Should be implemented by UCLASS_PMIC device drivers. The standard
+ * device operations provides the I/O interface for it's childs.
+ *
+ * @reg_count: devices register count
+ * @read: read 'len' bytes at "reg" and store it into the 'buffer'
+ * @write: write 'len' bytes from the 'buffer' to the register at 'reg' address
+ */
+struct dm_pmic_ops {
+ int reg_count;
+ int (*read)(struct udevice *dev, uint reg, uint8_t *buffer, int len);
+ int (*write)(struct udevice *dev, uint reg, const uint8_t *buffer,
+ int len);
+};
+
+/* enum pmic_op_type - used for various pmic devices operation calls,
+ * for reduce a number of lines with the same code for read/write or get/set.
+ *
+ * @PMIC_OP_GET - get operation
+ * @PMIC_OP_SET - set operation
+*/
+enum pmic_op_type {
+ PMIC_OP_GET,
+ PMIC_OP_SET,
+};
+
+/**
+ * struct pmic_child_info - basic device's child info for bind child nodes with
+ * the driver by the node name prefix and driver name. This is a helper struct
+ * for function: pmic_bind_childs().
+ *
+ * @prefix - child node name prefix (or its name if is unique or single)
+ * @driver - driver name for the sub-node with prefix
+ */
+struct pmic_child_info {
+ const char *prefix;
+ const char *driver;
+};
+
+/* drivers/power/pmic-uclass.c */
+
+/**
+ * pmic_bind_childs() - bind drivers for given parent pmic, using child info
+ * found in 'child_info' array.
+ *
+ * @pmic - pmic device - the parent of found child's
+ * @child_info - N-childs info array
+ * @return a positive number of childs, or 0 if no child found (error)
+ *
+ * Note: For N-childs the child_info array should have N+1 entries and the last
+ * entry prefix should be NULL - the same as for drivers compatible.
+ *
+ * For example, a single prefix info (N=1):
+ * static const struct pmic_child_info bind_info[] = {
+ * { .prefix = "ldo", .driver = "ldo_driver" },
+ * { },
+ * };
+ *
+ * This function is useful for regulator sub-nodes:
+ * my_regulator at 0xa {
+ * reg = <0xa>;
+ * (pmic - bind automatically by compatible)
+ * compatible = "my_pmic";
+ * ...
+ * (pmic's childs - bind by pmic_bind_childs())
+ * (nodes prefix: "ldo", driver: "my_regulator_ldo")
+ * ldo1 { ... };
+ * ldo2 { ... };
+ *
+ * (nodes prefix: "buck", driver: "my_regulator_buck")
+ * buck1 { ... };
+ * buck2 { ... };
+ * };
+ */
+int pmic_bind_childs(struct udevice *pmic, int offset,
+ const struct pmic_child_info *child_info);
+
+/**
+ * pmic_get: get the pmic device using its name
+ *
+ * @name - device name
+ * @devp - returned pointer to the pmic device
+ * @return 0 on success or negative value of errno.
+ *
+ * The returned devp device can be used with pmic_read/write calls
+ */
+int pmic_get(const char *name, struct udevice **devp);
+
+/**
+ * pmic_reg_count: get the pmic register count
+ *
+ * The required pmic device can be obtained by 'pmic_get()'
+ *
+ * @dev - pointer to the UCLASS_PMIC device
+ * @return register count value on success or negative value of errno.
+ */
+int pmic_reg_count(struct udevice *dev);
+
+/**
+ * pmic_read/write: read/write to the UCLASS_PMIC device
+ *
+ * The required pmic device can be obtained by 'pmic_get()'
+ *
+ * @pmic - pointer to the UCLASS_PMIC device
+ * @reg - device register offset
+ * @buffer - pointer to read/write buffer
+ * @len - byte count for read/write
+ * @return 0 on success or negative value of errno.
+ */
+int pmic_read(struct udevice *dev, uint reg, uint8_t *buffer, int len);
+int pmic_write(struct udevice *dev, uint reg, const uint8_t *buffer, int len);
+#endif /* CONFIG_DM_PMIC */

+#ifdef CONFIG_POWER
int pmic_init(unsigned char bus);
int power_init_board(void);
int pmic_dialog_init(unsigned char bus);
@@ -88,6 +276,7 @@ int pmic_probe(struct pmic *p);
int pmic_reg_read(struct pmic *p, u32 reg, u32 *val);
int pmic_reg_write(struct pmic *p, u32 reg, u32 val);
int pmic_set_output(struct pmic *p, u32 reg, int ldo, int on);
+#endif

#define pmic_i2c_addr (p->hw.i2c.addr)
#define pmic_i2c_tx_num (p->hw.i2c.tx_num)
--
1.9.1