[U-Boot] [PATCH v1 12/16] drivers: spmi: Add support for Qualcomm SPMI bus driver

Mateusz Kulikowski
2016-01-06T18:21:24Z

Support SPMI arbiter on Qualcomm Snapdragon devices.

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

Changes in v1:
- add binding documentation and better Kconfig help
- Changed a bit mapping
- Change include order
- Use clrsetbits* where possible
- Add one more supported dts id
- Handle missing fields in dt properly

doc/device-tree-bindings/spmi/spmi-msm.txt | 26 ++++
drivers/spmi/Kconfig | 7 +-
drivers/spmi/Makefile | 1 +
drivers/spmi/spmi-msm.c | 188 +++++++++++++++++++++++++++++
4 files changed, 221 insertions(+), 1 deletion(-)
create mode 100644 doc/device-tree-bindings/spmi/spmi-msm.txt
create mode 100644 drivers/spmi/spmi-msm.c

diff --git a/doc/device-tree-bindings/spmi/spmi-msm.txt b/doc/device-tree-bindings/spmi/spmi-msm.txt
new file mode 100644
index 0000000..ae47673
--- /dev/null
+++ b/doc/device-tree-bindings/spmi/spmi-msm.txt
@@ -0,0 +1,26 @@
+Qualcomm SPMI arbiter/bus driver
+
+This is bus driver for Qualcomm chips that use SPMI to communicate with PMICs.
+
+Required properties:
+- compatible: "qcom,spmi-pmic-arb"
+- reg: Register block adresses and sizes for various parts of device:
+ 1) PMIC arbiter channel mapping base (PMIC_ARB_REG_CHNLn)
+ 2) SPMI write command (master) registers (PMIC_ARB_CORE_SW_DEC_CHANNELS)
+ 3) SPMI read command (observer) registers (PMIC_ARB_CORE_REGISTERS_OBS)
+
+Optional properties (if not set by parent):
+- #address-cells: 0x1 - childs slave ID address
+- #size-cells: 0x1
+
+All PMICs should be placed as a child nodes of bus arbiter.
+Automatic detection of childs is currently not supported.
+
+Example:
+
+spmi at 200f000 {
+ compatible = "qcom,spmi-pmic-arb";
+ reg = <0x200f800 0x200 0x2400000 0x400000 0x2c00000 0x400000>;
+ #address-cells = <0x1>;
+ #size-cells = <0x1>;
+};
diff --git a/drivers/spmi/Kconfig b/drivers/spmi/Kconfig
index e3e8216..9632b14 100644
--- a/drivers/spmi/Kconfig
+++ b/drivers/spmi/Kconfig
@@ -8,11 +8,16 @@ config DM_SPMI
SPMI (System Power Management Interface) bus is used
to connect PMIC devices on various SoCs.

+config SPMI_MSM
+ boolean "Support Qualcomm SPMI bus"
+ depends on DM_SPMI
+ ---help---
+ Support SPMI bus implementation found on Qualcomm Snapdragon SoCs.
+
config SPMI_SANDBOX
boolean "Support for Sandbox SPMI bus"
depends on DM_SPMI
---help---
Demo SPMI bus implementation. Emulates part of PM8916 as single
slave (0) on bus. It has 4 GPIO peripherals, pid 0xC0-0xC3.
-
endmenu
diff --git a/drivers/spmi/Makefile b/drivers/spmi/Makefile
index 035d466..caad96f 100644
--- a/drivers/spmi/Makefile
+++ b/drivers/spmi/Makefile
@@ -5,4 +5,5 @@
#

obj-$(CONFIG_DM_SPMI) += spmi-uclass.o
+obj-$(CONFIG_SPMI_MSM) += spmi-msm.o
obj-$(CONFIG_SPMI_SANDBOX) += spmi-sandbox.o
diff --git a/drivers/spmi/spmi-msm.c b/drivers/spmi/spmi-msm.c
new file mode 100644
index 0000000..c1e7a3d
--- /dev/null
+++ b/drivers/spmi/spmi-msm.c
@@ -0,0 +1,188 @@
+/*
+ * Qualcomm SPMI bus driver
+ *
+ * (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
+ *
+ * Loosely based on Little Kernel driver
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <spmi/spmi.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define ARB_CHANNEL_OFFSET(n) (0x4 * (n))
+#define SPMI_CH_OFFSET(chnl) ((chnl) * 0x8000)
+
+#define SPMI_REG_CMD0 0x0
+#define SPMI_REG_CONFIG 0x4
+#define SPMI_REG_STATUS 0x8
+#define SPMI_REG_WDATA 0x10
+#define SPMI_REG_RDATA 0x18
+
+#define SPMI_CMD_OPCODE_SHIFT 27
+#define SPMI_CMD_SLAVE_ID_SHIFT 20
+#define SPMI_CMD_ADDR_SHIFT 12
+#define SPMI_CMD_ADDR_OFFSET_SHIFT 4
+#define SPMI_CMD_BYTE_CNT_SHIFT 0
+
+#define SPMI_CMD_EXT_REG_WRITE_LONG 0x00
+#define SPMI_CMD_EXT_REG_READ_LONG 0x01
+
+#define SPMI_STATUS_DONE 0x1
+
+#define SPMI_MAX_CHANNELS 128
+#define SPMI_MAX_SLAVES 16
+#define SPMI_MAX_PERIPH 256
+
+struct msm_spmi_priv {
+ phys_addr_t arb_chnl; /* ARB channel mapping base */
+ phys_addr_t spmi_core; /* SPMI core */
+ phys_addr_t spmi_obs; /* SPMI observer */
+ /* SPMI channel map */
+ uint8_t channel_map[SPMI_MAX_SLAVES][SPMI_MAX_PERIPH];
+};
+
+static int msm_spmi_write(struct udevice *dev, int usid, int pid, int off,
+ uint8_t val)
+{
+ struct msm_spmi_priv *p = dev_get_priv(dev);
+ unsigned channel;
+ uint32_t reg = 0;
+
+ if (usid >= SPMI_MAX_SLAVES)
+ return -EIO;
+ if (pid >= SPMI_MAX_PERIPH)
+ return -EIO;
+
+ channel = p->channel_map[usid][pid];
+
+ /* Disable IRQ mode for the current channel*/
+ writel(0x0, p->spmi_core + SPMI_CH_OFFSET(channel) + SPMI_REG_CONFIG);
+
+ /* Write single byte */
+ writel(val, p->spmi_core + SPMI_CH_OFFSET(channel) + SPMI_REG_WDATA);
+
+ /* Prepare write command */
+ reg |= SPMI_CMD_EXT_REG_WRITE_LONG << SPMI_CMD_OPCODE_SHIFT;
+ reg |= (usid << SPMI_CMD_SLAVE_ID_SHIFT);
+ reg |= (pid << SPMI_CMD_ADDR_SHIFT);
+ reg |= (off << SPMI_CMD_ADDR_OFFSET_SHIFT);
+ reg |= 1; /* byte count */
+
+ /* Send write command */
+ writel(reg, p->spmi_core + SPMI_CH_OFFSET(channel) + SPMI_REG_CMD0);
+
+ /* Wait till CMD DONE status */
+ reg = 0;
+ while (!reg) {
+ reg = readl(p->spmi_core + SPMI_CH_OFFSET(channel) +
+ SPMI_REG_STATUS);
+ }
+
+ if (reg ^ SPMI_STATUS_DONE) {
+ printf("SPMI write failure.\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int msm_spmi_read(struct udevice *dev, int usid, int pid, int off)
+{
+ struct msm_spmi_priv *p = dev_get_priv(dev);
+ unsigned channel;
+ uint32_t reg = 0;
+
+ if (usid >= SPMI_MAX_SLAVES)
+ return -EIO;
+ if (pid >= SPMI_MAX_PERIPH)
+ return -EIO;
+
+ channel = p->channel_map[usid][pid];
+
+ /* Disable IRQ mode for the current channel*/
+ writel(0x0, p->spmi_obs + SPMI_CH_OFFSET(channel) + SPMI_REG_CONFIG);
+
+ /* Prepare read command */
+ reg |= SPMI_CMD_EXT_REG_READ_LONG << SPMI_CMD_OPCODE_SHIFT;
+ reg |= (usid << SPMI_CMD_SLAVE_ID_SHIFT);
+ reg |= (pid << SPMI_CMD_ADDR_SHIFT);
+ reg |= (off << SPMI_CMD_ADDR_OFFSET_SHIFT);
+ reg |= 1; /* byte count */
+
+ /* Request read */
+ writel(reg, p->spmi_obs + SPMI_CH_OFFSET(channel) + SPMI_REG_CMD0);
+
+ /* Wait till CMD DONE status */
+ reg = 0;
+ while (!reg) {
+ reg = readl(p->spmi_obs + SPMI_CH_OFFSET(channel) +
+ SPMI_REG_STATUS);
+ }
+
+ if (reg ^ SPMI_STATUS_DONE) {
+ printf("SPMI read failure.\n");
+ return -EIO;
+ }
+
+ /* Read the data */
+ return readl(p->spmi_obs + SPMI_CH_OFFSET(channel) + SPMI_REG_RDATA) &
+ 0xFF;
+}
+
+static struct dm_spmi_ops msm_spmi_ops = {
+ .read = msm_spmi_read,
+ .write = msm_spmi_write,
+};
+
+static int msm_spmi_probe(struct udevice *dev)
+{
+ struct udevice *parent = dev->parent;
+ struct msm_spmi_priv *priv = dev_get_priv(dev);
+ int i;
+
+ priv->arb_chnl = dev_get_addr(dev);
+ priv->spmi_core = fdtdec_get_addr_size_auto_parent(gd->fdt_blob,
+ parent->of_offset,
+ dev->of_offset,
+ "reg", 1, NULL);
+ priv->spmi_obs = fdtdec_get_addr_size_auto_parent(gd->fdt_blob,
+ parent->of_offset,
+ dev->of_offset, "reg",
+ 2, NULL);
+ if (priv->arb_chnl == FDT_ADDR_T_NONE ||
+ priv->spmi_core == FDT_ADDR_T_NONE ||
+ priv->spmi_obs == FDT_ADDR_T_NONE)
+ return -EINVAL;
+
+ /* Scan peripherals connected to each SPMI channel */
+ for (i = 0; i < SPMI_MAX_CHANNELS ; i++) {
+ uint32_t periph = readl(priv->arb_chnl + ARB_CHANNEL_OFFSET(i));
+ uint8_t slave_id = (periph & 0xf0000) >> 16;
+ uint8_t pid = (periph & 0xff00) >> 8;
+
+ priv->channel_map[slave_id][pid] = i;
+ }
+ return 0;
+}
+
+static const struct udevice_id msm_spmi_ids[] = {
+ { .compatible = "qcom,spmi-pmic-arb" },
+ { }
+};
+
+U_BOOT_DRIVER(msm_spmi) = {
+ .name = "msm_spmi",
+ .id = UCLASS_SPMI,
+ .of_match = msm_spmi_ids,
+ .ops = &msm_spmi_ops,
+ .probe = msm_spmi_probe,
+ .priv_auto_alloc_size = sizeof(struct msm_spmi_priv),
+};
--
2.5.0