[PATCH v4 2/4] nvmem: add snvs_lpgpr for freescale imx6
Oleksij Rempel
o.rempel at pengutronix.de
Mon Mar 27 08:17:39 PDT 2017
From: Steffen Trumtrar <s.trumtrar at pengutronix.de>
SNVS LPGPR is Non Volatile Low Power Generic Purpose Register which
can be used as part of nvmem framework.
Signed-off-by: Steffen Trumtrar <s.trumtrar at pengutronix.de>
Signed-off-by: Oleksij Rempel <o.rempel at pengutronix.de>
---
drivers/nvmem/Kconfig | 10 ++++
drivers/nvmem/Makefile | 4 ++
drivers/nvmem/snvs_lpgpr.c | 115 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 129 insertions(+)
create mode 100644 drivers/nvmem/snvs_lpgpr.c
diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 218be05b2..d801cc25a 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -6,3 +6,13 @@ menuconfig NVMEM
This framework is designed to provide a generic interface to NVMEM
If unsure, say no.
+
+if NVMEM
+
+config NVMEM_SNVS_LPGPR
+ tristate "Freescale SNVS LPGPR support"
+ select MFD_SYSCON
+ help
+ If you say yes here you get NVMEM support for the Freescale SNVS
+ Low Power Generic Purpose Register (LPGPR).
+endif
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index 6df2c6952..32522e9fb 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -4,3 +4,7 @@
obj-$(CONFIG_NVMEM) += nvmem_core.o
nvmem_core-y := core.o
+
+# Devices
+obj-$(CONFIG_NVMEM_SNVS_LPGPR) += nvmem_snvs_lpgpr.o
+nvmem_snvs_lpgpr-y := snvs_lpgpr.o
diff --git a/drivers/nvmem/snvs_lpgpr.c b/drivers/nvmem/snvs_lpgpr.c
new file mode 100644
index 000000000..74118a6b7
--- /dev/null
+++ b/drivers/nvmem/snvs_lpgpr.c
@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2015 Pengutronix, Steffen Trumtrar <kernel at pengutronix.de>
+ * Copyright (c) 2017 Pengutronix, Oleksij Rempel <kernel at pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ */
+#include <common.h>
+#include <driver.h>
+#include <init.h>
+#include <io.h>
+#include <of.h>
+#include <malloc.h>
+#include <regmap.h>
+#include <mfd/syscon.h>
+#include <linux/nvmem-provider.h>
+
+struct snvs_lpgpr_priv {
+ struct device_d *dev;
+ struct regmap *regmap;
+ int offset;
+ struct nvmem_config cfg;
+};
+
+static int snvs_lpgpr_write(struct device_d *dev, const int reg,
+ const void *_val, int bytes)
+{
+ struct snvs_lpgpr_priv *priv = dev->parent->priv;
+ const u32 *val = _val;
+ int i = 0, words = bytes / 4;
+
+ while (words--)
+ regmap_write(priv->regmap, priv->offset + reg + (i++ * 4),
+ *val++);
+
+ return 0;
+}
+
+static int snvs_lpgpr_read(struct device_d *dev, const int reg, void *_val,
+ int bytes)
+{
+ struct snvs_lpgpr_priv *priv = dev->parent->priv;
+ u32 *val = _val;
+ int i = 0, words = bytes / 4;
+
+ while (words--)
+ regmap_read(priv->regmap, priv->offset + reg + (i++ * 4),
+ val++);
+
+
+ return 0;
+}
+
+static const struct nvmem_bus snvs_lpgpr_nvmem_bus = {
+ .write = snvs_lpgpr_write,
+ .read = snvs_lpgpr_read,
+};
+
+static int snvs_lpgpr_probe(struct device_d *dev)
+{
+ struct device_node *node = dev->device_node;
+ struct snvs_lpgpr_priv *priv;
+ struct nvmem_config *cfg;
+ struct nvmem_device *nvmem;
+ int err;
+
+ if (!node)
+ return -ENOENT;
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->regmap = syscon_node_to_regmap(of_get_parent(node));
+ if (IS_ERR(priv->regmap)) {
+ free(priv);
+ return PTR_ERR(priv->regmap);
+ }
+
+ err = of_property_read_u32(node, "offset", &priv->offset);
+ if (err)
+ return err;
+
+ cfg = &priv->cfg;
+ cfg->name = dev_name(dev);
+ cfg->dev = dev;
+ cfg->stride = 4,
+ cfg->word_size = 4,
+ cfg->size = 4,
+ cfg->bus = &snvs_lpgpr_nvmem_bus,
+
+ nvmem = nvmem_register(cfg);
+ if (IS_ERR(nvmem)) {
+ free(priv);
+ return PTR_ERR(nvmem);
+ }
+
+ dev->priv = priv;
+
+ return 0;
+}
+
+static __maybe_unused struct of_device_id snvs_lpgpr_dt_ids[] = {
+ { .compatible = "fsl,imx6sl-snvs-lpgpr", },
+ { .compatible = "fsl,imx6q-snvs-lpgpr", },
+ { },
+};
+
+static struct driver_d snvs_lpgpr_driver = {
+ .name = "nvmem-snvs-lpgpr",
+ .probe = snvs_lpgpr_probe,
+ .of_compatible = DRV_OF_COMPAT(snvs_lpgpr_dt_ids),
+};
+device_platform_driver(snvs_lpgpr_driver);
--
2.11.0
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