[U-Boot] [RFC PATCH 07/11] drivers: spmi: Add support for Qualcomm SPMI bus driver

Mateusz Kulikowski mateusz.kulikowski at gmail.com
Thu Dec 10 22:41:43 CET 2015


Support SPMI arbiter on Qualcomm Snapdragon devices.

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

 drivers/spmi/Kconfig    |   6 ++
 drivers/spmi/Makefile   |   1 +
 drivers/spmi/spmi-msm.c | 183 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 190 insertions(+)
 create mode 100644 drivers/spmi/spmi-msm.c

diff --git a/drivers/spmi/Kconfig b/drivers/spmi/Kconfig
index 2d8d78b..4f17df0 100644
--- a/drivers/spmi/Kconfig
+++ b/drivers/spmi/Kconfig
@@ -7,4 +7,10 @@ config DM_SPMI
 	Select this to enable to support SPMI bus.
 	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 implementation found on Qualcomm Snapdragon SoCs.
 endmenu
diff --git a/drivers/spmi/Makefile b/drivers/spmi/Makefile
index 2015b1a..419fe1d 100644
--- a/drivers/spmi/Makefile
+++ b/drivers/spmi/Makefile
@@ -5,3 +5,4 @@
 #
 
 obj-$(CONFIG_DM_SPMI)  += spmi-uclass.o
+obj-$(CONFIG_SPMI_MSM) += spmi-msm.o
diff --git a/drivers/spmi/spmi-msm.c b/drivers/spmi/spmi-msm.c
new file mode 100644
index 0000000..6781a92
--- /dev/null
+++ b/drivers/spmi/spmi-msm.c
@@ -0,0 +1,183 @@
+/*
+ * Qualcomm SPMI bus driver
+ *
+ * (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski at gmail.com>
+ *
+ * Loosely based on Little Kernel driver
+ *
+ * SPDX-License-Identifier:	BSD-3-Clause
+ */
+
+#include <asm/io.h>
+#include <common.h>
+#include <fdtdec.h>
+#include <errno.h>
+#include <dm.h>
+#include <spmi/spmi.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define ARB_CHANNEL_OFFSET(n)		(0x800 + 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_core; /* ARB Core 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 msm_spmi_priv *priv = dev_get_priv(dev);
+	int i;
+
+	priv->arb_core = dev_get_addr(dev);
+	priv->spmi_core = fdtdec_get_addr_size_auto_parent(gd->fdt_blob,
+							   dev->parent->of_offset,
+							   dev->of_offset, "reg",
+							   1, NULL);
+	priv->spmi_obs = fdtdec_get_addr_size_auto_parent(gd->fdt_blob,
+							  dev->parent->of_offset,
+							  dev->of_offset, "reg",
+							  2, NULL);
+
+	/* Scan peripherals connected to each SPMI channel */
+	for (i = 0; i < SPMI_MAX_CHANNELS ; i++) {
+		uint32_t periph = readl(priv->arb_core + 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



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