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Anirudh Ghayalgregkh
Anirudh Ghayal
authored and
gregkh
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nvmem: add QTI SDAM driver
QTI SDAM driver allows PMIC peripherals to access the shared memory that is available on QTI PMICs. Use subsys_initcall as PMIC SDAM NV memory is accessed by multiple PMIC drivers (charger, fuel gauge) to store/restore data across reboots required during their initialization. Signed-off-by: Anirudh Ghayal <[email protected]> Signed-off-by: Shyam Kumar Thella <[email protected]> Signed-off-by: Srinivas Kandagatla <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
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‎drivers/nvmem/Kconfig

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@@ -109,6 +109,14 @@ config QCOM_QFPROM
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This driver can also be built as a module. If so, the module
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will be called nvmem_qfprom.
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config NVMEM_SPMI_SDAM
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tristate "SPMI SDAM Support"
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depends on SPMI
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help
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This driver supports the Shared Direct Access Memory Module on
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Qualcomm Technologies, Inc. PMICs. It provides the clients
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an interface to read/write to the SDAM module's shared memory.
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config ROCKCHIP_EFUSE
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tristate "Rockchip eFuse Support"
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depends on ARCH_ROCKCHIP || COMPILE_TEST

‎drivers/nvmem/Makefile

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@@ -28,6 +28,8 @@ obj-$(CONFIG_MTK_EFUSE) += nvmem_mtk-efuse.o
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nvmem_mtk-efuse-y := mtk-efuse.o
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obj-$(CONFIG_QCOM_QFPROM) += nvmem_qfprom.o
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nvmem_qfprom-y := qfprom.o
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obj-$(CONFIG_NVMEM_SPMI_SDAM) += nvmem_qcom-spmi-sdam.o
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nvmem_qcom-spmi-sdam-y += qcom-spmi-sdam.o
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obj-$(CONFIG_ROCKCHIP_EFUSE) += nvmem_rockchip_efuse.o
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nvmem_rockchip_efuse-y := rockchip-efuse.o
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obj-$(CONFIG_ROCKCHIP_OTP) += nvmem-rockchip-otp.o

‎drivers/nvmem/qcom-spmi-sdam.c

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@@ -0,0 +1,192 @@
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// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (c) 2017 The Linux Foundation. All rights reserved.
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*/
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/of_platform.h>
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#include <linux/nvmem-provider.h>
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#include <linux/regmap.h>
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#define SDAM_MEM_START 0x40
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#define REGISTER_MAP_ID 0x40
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#define REGISTER_MAP_VERSION 0x41
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#define SDAM_SIZE 0x44
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#define SDAM_PBS_TRIG_SET 0xE5
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#define SDAM_PBS_TRIG_CLR 0xE6
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struct sdam_chip {
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struct platform_device *pdev;
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struct regmap *regmap;
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struct nvmem_config sdam_config;
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unsigned int base;
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unsigned int size;
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};
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/* read only register offsets */
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static const u8 sdam_ro_map[] = {
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REGISTER_MAP_ID,
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REGISTER_MAP_VERSION,
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SDAM_SIZE
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};
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static bool sdam_is_valid(struct sdam_chip *sdam, unsigned int offset,
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size_t len)
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{
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unsigned int sdam_mem_end = SDAM_MEM_START + sdam->size - 1;
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if (!len)
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return false;
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if (offset >= SDAM_MEM_START && offset <= sdam_mem_end
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&& (offset + len - 1) <= sdam_mem_end)
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return true;
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else if ((offset == SDAM_PBS_TRIG_SET || offset == SDAM_PBS_TRIG_CLR)
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&& (len == 1))
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return true;
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return false;
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}
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static bool sdam_is_ro(unsigned int offset, size_t len)
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{
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int i;
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for (i = 0; i < ARRAY_SIZE(sdam_ro_map); i++)
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if (offset <= sdam_ro_map[i] && (offset + len) > sdam_ro_map[i])
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return true;
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return false;
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}
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static int sdam_read(void *priv, unsigned int offset, void *val,
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size_t bytes)
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{
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struct sdam_chip *sdam = priv;
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struct device *dev = &sdam->pdev->dev;
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int rc;
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if (!sdam_is_valid(sdam, offset, bytes)) {
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dev_err(dev, "Invalid SDAM offset %#x len=%zd\n",
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offset, bytes);
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return -EINVAL;
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}
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rc = regmap_bulk_read(sdam->regmap, sdam->base + offset, val, bytes);
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if (rc < 0)
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dev_err(dev, "Failed to read SDAM offset %#x len=%zd, rc=%d\n",
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offset, bytes, rc);
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return rc;
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}
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static int sdam_write(void *priv, unsigned int offset, void *val,
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size_t bytes)
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{
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struct sdam_chip *sdam = priv;
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struct device *dev = &sdam->pdev->dev;
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int rc;
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if (!sdam_is_valid(sdam, offset, bytes)) {
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dev_err(dev, "Invalid SDAM offset %#x len=%zd\n",
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offset, bytes);
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return -EINVAL;
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}
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if (sdam_is_ro(offset, bytes)) {
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dev_err(dev, "Invalid write offset %#x len=%zd\n",
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offset, bytes);
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return -EINVAL;
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}
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rc = regmap_bulk_write(sdam->regmap, sdam->base + offset, val, bytes);
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if (rc < 0)
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dev_err(dev, "Failed to write SDAM offset %#x len=%zd, rc=%d\n",
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offset, bytes, rc);
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return rc;
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}
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static int sdam_probe(struct platform_device *pdev)
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{
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struct sdam_chip *sdam;
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struct nvmem_device *nvmem;
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unsigned int val;
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int rc;
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sdam = devm_kzalloc(&pdev->dev, sizeof(*sdam), GFP_KERNEL);
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if (!sdam)
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return -ENOMEM;
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sdam->regmap = dev_get_regmap(pdev->dev.parent, NULL);
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if (!sdam->regmap) {
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dev_err(&pdev->dev, "Failed to get regmap handle\n");
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return -ENXIO;
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}
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rc = of_property_read_u32(pdev->dev.of_node, "reg", &sdam->base);
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if (rc < 0) {
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dev_err(&pdev->dev, "Failed to get SDAM base, rc=%d\n", rc);
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return -EINVAL;
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}
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rc = regmap_read(sdam->regmap, sdam->base + SDAM_SIZE, &val);
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if (rc < 0) {
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dev_err(&pdev->dev, "Failed to read SDAM_SIZE rc=%d\n", rc);
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return -EINVAL;
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}
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sdam->size = val * 32;
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sdam->sdam_config.dev = &pdev->dev;
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sdam->sdam_config.name = "spmi_sdam";
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sdam->sdam_config.id = pdev->id;
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sdam->sdam_config.owner = THIS_MODULE,
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sdam->sdam_config.stride = 1;
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sdam->sdam_config.word_size = 1;
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sdam->sdam_config.reg_read = sdam_read;
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sdam->sdam_config.reg_write = sdam_write;
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sdam->sdam_config.priv = sdam;
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nvmem = devm_nvmem_register(&pdev->dev, &sdam->sdam_config);
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if (IS_ERR(nvmem)) {
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dev_err(&pdev->dev,
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"Failed to register SDAM nvmem device rc=%ld\n",
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PTR_ERR(nvmem));
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return -ENXIO;
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}
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dev_dbg(&pdev->dev,
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"SDAM base=%#x size=%u registered successfully\n",
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sdam->base, sdam->size);
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return 0;
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}
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static const struct of_device_id sdam_match_table[] = {
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{ .compatible = "qcom,spmi-sdam" },
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{},
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};
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static struct platform_driver sdam_driver = {
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.driver = {
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.name = "qcom,spmi-sdam",
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.of_match_table = sdam_match_table,
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},
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.probe = sdam_probe,
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};
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static int __init sdam_init(void)
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{
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return platform_driver_register(&sdam_driver);
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}
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subsys_initcall(sdam_init);
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static void __exit sdam_exit(void)
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{
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return platform_driver_unregister(&sdam_driver);
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}
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module_exit(sdam_exit);
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MODULE_DESCRIPTION("QCOM SPMI SDAM driver");
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MODULE_LICENSE("GPL v2");

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