Merge "NFC: Introduce a presence check" (e7062bf3) · Commits · e / devices / android_kernel_sony_msm8994

drivers/nfc/nfc-nci.c

+94 −34

Original line number	Diff line number	Diff line
		@@ -96,6 +96,7 @@ struct qca199x_dev {
		};

		static int nfc_i2c_write(struct i2c_client client, u8 buf, int len);
		static int nfcc_hw_check(struct i2c_client *client, unsigned short curr_addr);
		static int nfcc_initialise(struct i2c_client *client, unsigned short curr_addr);
		static int qca199x_clock_select(struct qca199x_dev *qca199x_dev);
		static int qca199x_clock_deselect(struct qca199x_dev *qca199x_dev);
		@@ -887,6 +888,33 @@ static int nfc_i2c_write(struct i2c_client client, u8 buf, int len)
		return r;
		}

		/* Check for availability of qca199x_ NFC controller hardware */
		static int nfcc_hw_check(struct i2c_client *client, unsigned short curr_addr)
		{
		int r = 0;
		unsigned char buf = 0;

		client->addr = curr_addr;
		/* Set-up Addr 0. No data written */
		r = i2c_master_send(client, &buf, 1);
		if (r < 0)
		goto err_presence_check;
		buf = 0;
		/* Read back from Addr 0 */
		r = i2c_master_recv(client, &buf, 1);
		if (r < 0)
		goto err_presence_check;

		r = 0;
		return r;

		err_presence_check:
		r = -ENXIO;
		dev_err(&client->dev,
		"nfc-nci nfcc_presence check - no NFCC available\n");
		return r;
		}
		/* Initialise qca199x_ NFC controller hardware */
		static int nfcc_initialise(struct i2c_client *client, unsigned short curr_addr)
		{
		int r = 0;
		@@ -1205,12 +1233,51 @@ static int qca199x_probe(struct i2c_client *client,
		return -ENOMEM;
		}
		qca199x_dev->client = client;

		/*
		* To be efficient we need to test whether nfcc hardware is physically
		* present before attempting further hardware initialisation.
		* For this we need to be sure the device is in ULPM state by
		* setting disable line low early on.
		*
		*/


		if (gpio_is_valid(platform_data->dis_gpio)) {
		r = gpio_request(platform_data->dis_gpio, "nfc_reset_gpio");
		if (r) {
		dev_err(&client->dev,
		"NFC: unable to request gpio [%d]\n",
		platform_data->dis_gpio);
		goto err_free_dev;
		}
		r = gpio_direction_output(platform_data->dis_gpio, 1);
		if (r) {
		dev_err(&client->dev,
		"NFC: unable to set direction for gpio [%d]\n",
		platform_data->dis_gpio);
		goto err_dis_gpio;
		}
		} else {
		dev_err(&client->dev, "dis gpio not provided\n");
		goto err_free_dev;
		}

		/* Put device in ULPM */
		gpio_set_value(platform_data->dis_gpio, 0);
		r = nfcc_hw_check(client, platform_data->reg);
		if (r) {
		/* We don't think there is hardware but just in case HPD */
		gpio_set_value(platform_data->dis_gpio, 1);
		goto err_dis_gpio;
		}

		if (gpio_is_valid(platform_data->irq_gpio)) {
		r = gpio_request(platform_data->irq_gpio, "nfc_irq_gpio");
		if (r) {
		dev_err(&client->dev, "unable to request gpio [%d]\n",
		platform_data->irq_gpio);
		goto err_free_dev;
		goto err_dis_gpio;
		}
		r = gpio_direction_input(platform_data->irq_gpio);
		if (r) {
		@@ -1229,7 +1296,7 @@ static int qca199x_probe(struct i2c_client *client,

		} else {
		dev_err(&client->dev, "irq gpio not provided\n");
		goto err_free_dev;
		goto err_dis_gpio;
		}
		/* Interrupt from NFCC CLK_REQ to handle REF_CLK
		o/p gating/selection */
		@@ -1263,25 +1330,6 @@ static int qca199x_probe(struct i2c_client *client,
		goto err_irq;
		}
		}
		if (gpio_is_valid(platform_data->dis_gpio)) {
		r = gpio_request(platform_data->dis_gpio, "nfc_reset_gpio");
		if (r) {
		dev_err(&client->dev,
		"NFC: unable to request gpio [%d]\n",
		platform_data->dis_gpio);
		goto err_irq_clk;
		}
		r = gpio_direction_output(platform_data->dis_gpio, 1);
		if (r) {
		dev_err(&client->dev,
		"NFC: unable to set direction for gpio [%d]\n",
		platform_data->dis_gpio);
		goto err_dis_gpio;
		}
		} else {
		dev_err(&client->dev, "dis gpio not provided\n");
		goto err_irq_clk;
		}
		/* Get the clock source name and gpio from from Device Tree */
		qca199x_dev->clk_src_name = platform_data->clk_src_name;
		qca199x_dev->clk_src_gpio = platform_data->clk_src_gpio;
		@@ -1291,7 +1339,7 @@ static int qca199x_probe(struct i2c_client *client,
		if (r == -1)
		goto err_clk;
		else
		goto err_dis_gpio;
		goto err_irq_clk;
		}

		if (strcmp(platform_data->clk_src_name, "GPCLK2")) {
		@@ -1345,6 +1393,27 @@ static int qca199x_probe(struct i2c_client *client,
		goto err_misc_register;
		}


		/*
		* Reboot the NFCC now that all resources are ready
		*
		* The NFCC takes time to transition between power states.
		* We wait 20uS for the NFCC to shutdown. (HPD)
		* We wait 100uS for the NFCC to boot into ULPM.
		*/
		gpio_set_value(platform_data->dis_gpio, 1);/* HPD */
		msleep(20);
		gpio_set_value(platform_data->dis_gpio, 0);/* ULPM */
		msleep(100);


		/* Here we perform a second presence check. */
		r = nfcc_hw_check(client, platform_data->reg);
		if (r) {
		/* We don't think there is hardware but just in case HPD */
		gpio_set_value(platform_data->dis_gpio, 1);
		goto err_nfcc_not_present;
		}
		regulators.regulator = regulator_get(&client->dev, regulators.name);
		if (IS_ERR(regulators.regulator)) {
		r = PTR_ERR(regulators.regulator);
		@@ -1409,6 +1478,7 @@ err_create_workq:
		"nfc-nci probe: %s, work_queue creation failure\n",
		__func__);
		free_irq(client->irq, qca199x_dev);
		err_nfcc_not_present:
		err_request_irq_failed:
		misc_deregister(&qca199x_dev->qca199x_device);
		err_misc_register:
		@@ -1418,18 +1488,6 @@ err_clkreq_gpio:
		gpio_free(platform_data->clkreq_gpio);
		err_clk:
		qca199x_clock_deselect(qca199x_dev);
		err_dis_gpio:
		r = gpio_direction_input(platform_data->dis_gpio);
		if (r)
		dev_err(&client->dev, "nfc-nci probe: Unable to set direction\n");
		if ((!strcmp(platform_data->clk_src_name, "GPCLK")) \|\|
		(!strcmp(platform_data->clk_src_name, "GPCLK2"))) {
		r = gpio_direction_input(platform_data->clk_src_gpio);
		if (r)
		dev_err(&client->dev, "nfc-nci probe: Unable to set direction\n");
		gpio_free(platform_data->clk_src_gpio);
		}
		gpio_free(platform_data->dis_gpio);
		err_irq_clk:
		if ((!strcmp(platform_data->clk_src_name, "GPCLK")) \|\|
		(!strcmp(platform_data->clk_src_name, "GPCLK2"))) {
		@@ -1440,6 +1498,8 @@ err_irq_clk:
		}
		err_irq:
		gpio_free(platform_data->irq_gpio);
		err_dis_gpio:
		gpio_free(platform_data->dis_gpio);
		err_free_dev:
		kfree(qca199x_dev);
		return r;