mmi_nfc_clk.ko: Add dlkm to control clk

This dlkm will configure pm660 gpio 4 as interrupt. BB_CLK3 has
pin control enabled so gpio 4 logic high will enable clk.

Change-Id: I3dda722f184551b7b3be564b9f9e8c26ab3fafc7
Signed-off-by: Balachandar Swami <w60013@motorola.com>
Reviewed-on: https://gerrit.mot.com/1327541
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Reviewed-by: Rav(CR) Vembu <raviv@motorola.com>
Submit-Approved: Jira Key

drivers/nfc/mmi_nfc_clk/Android.mk

@@ -0,0 +1,8 @@
+DLKM_DIR := motorola/kernel/modules
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := mmi_nfc_clk.ko
+LOCAL_MODULE_TAGS := optional
+LOCAL_MODULE_PATH := $(KERNEL_MODULES_OUT)
+include $(DLKM_DIR)/AndroidKernelModule.mk

drivers/nfc/mmi_nfc_clk/Kbuild

@@ -0,0 +1,4 @@
+# add -Wall to try to catch everything we can.
+EXTRA_CFLAGS += -Wall
+
+obj-m += mmi_nfc_clk.o

drivers/nfc/mmi_nfc_clk/Makefile

@@ -0,0 +1,11 @@
+KERNEL_SRC ?= /lib/modules/$(shell uname -r)/build
+
+all:
+	$(MAKE) -C $(KERNEL_SRC) M=$(shell pwd) modules $(KBUILD_OPTIONS)
+
+modules_install:
+	$(MAKE) INSTALL_MOD_STRIP=1 -C $(KERNEL_SRC) M=$(shell pwd) modules_install
+
+clean:
+	$(MAKE) -C $(KERNEL_SRC) M=$(PWD) clean
+

drivers/nfc/mmi_nfc_clk/mmi_nfc_clk.c

@@ -0,0 +1,163 @@
+/*
+ * Copyright (C) 2019 Motorola Mobility LLC
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/version.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/irq.h>
+#include <linux/jiffies.h>
+#include <linux/uaccess.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+#include <linux/poll.h>
+#include <linux/miscdevice.h>
+#include <linux/spinlock.h>
+#include <linux/of_gpio.h>
+#include <linux/clk.h>
+
+#define DRIVER_VERSION "0.0.1"
+
+struct mmi_nfc_clk_drvdata {
+	struct device	*dev;
+	unsigned int clkreq_gpio;
+	unsigned int clkreq_irq;
+};
+
+static irqreturn_t mmi_nfc_clk_gpio_isr(int irq, void *dev_id)
+{
+	// 0x00005346 LN_BB_CLK3_EN_CTL is set to 0x01
+	//	Software control is off
+	//	PC_POLARITY - pin control polarity - logic high enables clock
+	//	FOLLOW_PC_EN - pin control enable is on
+	//
+	// PM660 GPIO 04 will trigger this ISR. As soon as MSM and PM660 is
+	// awake BB_CLK3 is enabled. No additional action is needed here.
+	return IRQ_HANDLED;
+}
+
+static int read_setup_clkreq_irq(struct platform_device *pdev,
+	struct mmi_nfc_clk_drvdata *drvdata)
+{
+	int rc = 0;
+	int gpio;
+	int irq;
+	const char *desc = "nfc_clkreq";
+
+	gpio = of_get_named_gpio(pdev->dev.of_node, "mmi,clkreq_gpio", 0);
+	if (gpio < 0) {
+		rc =  gpio;
+		dev_err(&pdev->dev, "probe: clkreq gpio not found, error=%d\n", rc);
+		goto end;
+	}
+	drvdata->clkreq_gpio = gpio;
+
+	rc = devm_gpio_request_one(&pdev->dev, drvdata->clkreq_gpio,
+		GPIOF_IN, desc);
+
+	if (rc < 0) {
+		dev_err(&pdev->dev, "probe: gpio (%d) request failed, error %d\n",
+			drvdata->clkreq_gpio, rc);
+		goto end;
+	}
+
+	irq = gpio_to_irq(drvdata->clkreq_gpio);
+	if (irq < 0) {
+		rc = irq;
+		dev_err(&pdev->dev, "probe: get irq failed for gpio %d, error %d\n",
+			drvdata->clkreq_gpio, rc);
+		goto end;
+	}
+	dev_dbg(&pdev->dev, "probe: gpio %d, irq %d\n", drvdata->clkreq_gpio, irq);
+
+	drvdata->clkreq_irq = irq;
+	rc = devm_request_irq(&pdev->dev, drvdata->clkreq_irq,
+		mmi_nfc_clk_gpio_isr, IRQF_TRIGGER_RISING,
+		desc, drvdata);
+
+	if (rc < 0) {
+		dev_err(&pdev->dev, "probe: unable to claim irq %d; error %d\n",
+			drvdata->clkreq_irq, rc);
+		goto end;
+	}
+
+	enable_irq_wake(drvdata->clkreq_irq);
+
+end:
+	return rc;
+}
+
+
+static int mmi_nfc_clk_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mmi_nfc_clk_drvdata *drvdata;
+	int rc = 0;
+
+	dev_dbg(&pdev->dev, "%s begin\n", __func__);
+	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	drvdata->dev = &pdev->dev;
+	platform_set_drvdata(pdev, drvdata);
+
+	rc = read_setup_clkreq_irq(pdev, drvdata);
+	if (rc < 0) {
+		dev_err(&pdev->dev, "probe: failed rc=%d\n", rc);
+		return rc;
+	}
+
+	device_init_wakeup(&pdev->dev, 1);
+	dev_info(&pdev->dev, "probe: success !\n");
+	return rc;
+}
+
+static int mmi_nfc_clk_remove(struct platform_device *pdev)
+{
+	device_init_wakeup(&pdev->dev, 0);
+	return 0;
+}
+
+
+static const struct of_device_id mmi_nfc_clk_match[] = {
+	{ .compatible = "mmi,nfc-clk" },
+	{}
+};
+
+static struct platform_driver mmi_nfc_clk_plat_driver = {
+	.probe = mmi_nfc_clk_probe,
+	.remove = mmi_nfc_clk_remove,
+	.driver = {
+		.name = "mmi_nfc_clk",
+		.owner = THIS_MODULE,
+		.of_match_table = mmi_nfc_clk_match,
+	},
+};
+
+module_platform_driver(mmi_nfc_clk_plat_driver);
+
+
+MODULE_AUTHOR("Motorola Mobiity");
+MODULE_DESCRIPTION("NFC Clock Enable/Disable driver");
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL");