| // SPDX-License-Identifier: GPL-1.0+ |
| // |
| // Copyright (c) 2008 Simtec Electronics |
| // http://armlinux.simtec.co.uk/ |
| // Ben Dooks <ben@simtec.co.uk>, <ben-linux@fluff.org> |
| // |
| // Samsung ADC device core |
| |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/mod_devicetable.h> |
| #include <linux/platform_device.h> |
| #include <linux/sched.h> |
| #include <linux/list.h> |
| #include <linux/slab.h> |
| #include <linux/err.h> |
| #include <linux/clk.h> |
| #include <linux/interrupt.h> |
| #include <linux/io.h> |
| #include <linux/regulator/consumer.h> |
| |
| #include <plat/regs-adc.h> |
| #include <linux/soc/samsung/s3c-adc.h> |
| |
| /* This driver is designed to control the usage of the ADC block between |
| * the touchscreen and any other drivers that may need to use it, such as |
| * the hwmon driver. |
| * |
| * Priority will be given to the touchscreen driver, but as this itself is |
| * rate limited it should not starve other requests which are processed in |
| * order that they are received. |
| * |
| * Each user registers to get a client block which uniquely identifies it |
| * and stores information such as the necessary functions to callback when |
| * action is required. |
| */ |
| |
| enum s3c_cpu_type { |
| TYPE_ADCV1, /* S3C24XX */ |
| TYPE_ADCV11, /* S3C2443 */ |
| TYPE_ADCV12, /* S3C2416, S3C2450 */ |
| TYPE_ADCV2, /* S3C64XX */ |
| TYPE_ADCV3, /* S5PV210, S5PC110, Exynos4210 */ |
| }; |
| |
| struct s3c_adc_client { |
| struct platform_device *pdev; |
| struct list_head pend; |
| wait_queue_head_t *wait; |
| |
| unsigned int nr_samples; |
| int result; |
| unsigned char is_ts; |
| unsigned char channel; |
| |
| void (*select_cb)(struct s3c_adc_client *c, unsigned selected); |
| void (*convert_cb)(struct s3c_adc_client *c, |
| unsigned val1, unsigned val2, |
| unsigned *samples_left); |
| }; |
| |
| struct adc_device { |
| struct platform_device *pdev; |
| struct platform_device *owner; |
| struct clk *clk; |
| struct s3c_adc_client *cur; |
| struct s3c_adc_client *ts_pend; |
| void __iomem *regs; |
| spinlock_t lock; |
| |
| unsigned int prescale; |
| |
| int irq; |
| struct regulator *vdd; |
| }; |
| |
| static struct adc_device *adc_dev; |
| |
| static LIST_HEAD(adc_pending); /* protected by adc_device.lock */ |
| |
| #define adc_dbg(_adc, msg...) dev_dbg(&(_adc)->pdev->dev, msg) |
| |
| static inline void s3c_adc_convert(struct adc_device *adc) |
| { |
| unsigned con = readl(adc->regs + S3C2410_ADCCON); |
| |
| con |= S3C2410_ADCCON_ENABLE_START; |
| writel(con, adc->regs + S3C2410_ADCCON); |
| } |
| |
| static inline void s3c_adc_select(struct adc_device *adc, |
| struct s3c_adc_client *client) |
| { |
| unsigned con = readl(adc->regs + S3C2410_ADCCON); |
| enum s3c_cpu_type cpu = platform_get_device_id(adc->pdev)->driver_data; |
| |
| client->select_cb(client, 1); |
| |
| if (cpu == TYPE_ADCV1 || cpu == TYPE_ADCV2) |
| con &= ~S3C2410_ADCCON_MUXMASK; |
| con &= ~S3C2410_ADCCON_STDBM; |
| con &= ~S3C2410_ADCCON_STARTMASK; |
| |
| if (!client->is_ts) { |
| if (cpu == TYPE_ADCV3) |
| writel(client->channel & 0xf, adc->regs + S5P_ADCMUX); |
| else if (cpu == TYPE_ADCV11 || cpu == TYPE_ADCV12) |
| writel(client->channel & 0xf, |
| adc->regs + S3C2443_ADCMUX); |
| else |
| con |= S3C2410_ADCCON_SELMUX(client->channel); |
| } |
| |
| writel(con, adc->regs + S3C2410_ADCCON); |
| } |
| |
| static void s3c_adc_dbgshow(struct adc_device *adc) |
| { |
| adc_dbg(adc, "CON=%08x, TSC=%08x, DLY=%08x\n", |
| readl(adc->regs + S3C2410_ADCCON), |
| readl(adc->regs + S3C2410_ADCTSC), |
| readl(adc->regs + S3C2410_ADCDLY)); |
| } |
| |
| static void s3c_adc_try(struct adc_device *adc) |
| { |
| struct s3c_adc_client *next = adc->ts_pend; |
| |
| if (!next && !list_empty(&adc_pending)) { |
| next = list_first_entry(&adc_pending, |
| struct s3c_adc_client, pend); |
| list_del(&next->pend); |
| } else |
| adc->ts_pend = NULL; |
| |
| if (next) { |
| adc_dbg(adc, "new client is %p\n", next); |
| adc->cur = next; |
| s3c_adc_select(adc, next); |
| s3c_adc_convert(adc); |
| s3c_adc_dbgshow(adc); |
| } |
| } |
| |
| int s3c_adc_start(struct s3c_adc_client *client, |
| unsigned int channel, unsigned int nr_samples) |
| { |
| struct adc_device *adc = adc_dev; |
| unsigned long flags; |
| |
| if (!adc) { |
| printk(KERN_ERR "%s: failed to find adc\n", __func__); |
| return -EINVAL; |
| } |
| |
| spin_lock_irqsave(&adc->lock, flags); |
| |
| if (client->is_ts && adc->ts_pend) { |
| spin_unlock_irqrestore(&adc->lock, flags); |
| return -EAGAIN; |
| } |
| |
| client->channel = channel; |
| client->nr_samples = nr_samples; |
| |
| if (client->is_ts) |
| adc->ts_pend = client; |
| else |
| list_add_tail(&client->pend, &adc_pending); |
| |
| if (!adc->cur) |
| s3c_adc_try(adc); |
| |
| spin_unlock_irqrestore(&adc->lock, flags); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(s3c_adc_start); |
| |
| static void s3c_convert_done(struct s3c_adc_client *client, |
| unsigned v, unsigned u, unsigned *left) |
| { |
| client->result = v; |
| wake_up(client->wait); |
| } |
| |
| int s3c_adc_read(struct s3c_adc_client *client, unsigned int ch) |
| { |
| DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake); |
| int ret; |
| |
| client->convert_cb = s3c_convert_done; |
| client->wait = &wake; |
| client->result = -1; |
| |
| ret = s3c_adc_start(client, ch, 1); |
| if (ret < 0) |
| goto err; |
| |
| ret = wait_event_timeout(wake, client->result >= 0, HZ / 2); |
| if (client->result < 0) { |
| ret = -ETIMEDOUT; |
| goto err; |
| } |
| |
| client->convert_cb = NULL; |
| return client->result; |
| |
| err: |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(s3c_adc_read); |
| |
| static void s3c_adc_default_select(struct s3c_adc_client *client, |
| unsigned select) |
| { |
| } |
| |
| struct s3c_adc_client *s3c_adc_register(struct platform_device *pdev, |
| void (*select)(struct s3c_adc_client *client, |
| unsigned int selected), |
| void (*conv)(struct s3c_adc_client *client, |
| unsigned d0, unsigned d1, |
| unsigned *samples_left), |
| unsigned int is_ts) |
| { |
| struct s3c_adc_client *client; |
| |
| WARN_ON(!pdev); |
| |
| if (!select) |
| select = s3c_adc_default_select; |
| |
| if (!pdev) |
| return ERR_PTR(-EINVAL); |
| |
| client = kzalloc(sizeof(*client), GFP_KERNEL); |
| if (!client) |
| return ERR_PTR(-ENOMEM); |
| |
| client->pdev = pdev; |
| client->is_ts = is_ts; |
| client->select_cb = select; |
| client->convert_cb = conv; |
| |
| return client; |
| } |
| EXPORT_SYMBOL_GPL(s3c_adc_register); |
| |
| void s3c_adc_release(struct s3c_adc_client *client) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&adc_dev->lock, flags); |
| |
| /* We should really check that nothing is in progress. */ |
| if (adc_dev->cur == client) |
| adc_dev->cur = NULL; |
| if (adc_dev->ts_pend == client) |
| adc_dev->ts_pend = NULL; |
| else { |
| struct list_head *p, *n; |
| struct s3c_adc_client *tmp; |
| |
| list_for_each_safe(p, n, &adc_pending) { |
| tmp = list_entry(p, struct s3c_adc_client, pend); |
| if (tmp == client) |
| list_del(&tmp->pend); |
| } |
| } |
| |
| if (adc_dev->cur == NULL) |
| s3c_adc_try(adc_dev); |
| |
| spin_unlock_irqrestore(&adc_dev->lock, flags); |
| kfree(client); |
| } |
| EXPORT_SYMBOL_GPL(s3c_adc_release); |
| |
| static irqreturn_t s3c_adc_irq(int irq, void *pw) |
| { |
| struct adc_device *adc = pw; |
| struct s3c_adc_client *client = adc->cur; |
| enum s3c_cpu_type cpu = platform_get_device_id(adc->pdev)->driver_data; |
| unsigned data0, data1; |
| |
| if (!client) { |
| dev_warn(&adc->pdev->dev, "%s: no adc pending\n", __func__); |
| goto exit; |
| } |
| |
| data0 = readl(adc->regs + S3C2410_ADCDAT0); |
| data1 = readl(adc->regs + S3C2410_ADCDAT1); |
| adc_dbg(adc, "read %d: 0x%04x, 0x%04x\n", client->nr_samples, data0, data1); |
| |
| client->nr_samples--; |
| |
| if (cpu == TYPE_ADCV1 || cpu == TYPE_ADCV11) { |
| data0 &= 0x3ff; |
| data1 &= 0x3ff; |
| } else { |
| /* S3C2416/S3C64XX/S5P ADC resolution is 12-bit */ |
| data0 &= 0xfff; |
| data1 &= 0xfff; |
| } |
| |
| if (client->convert_cb) |
| (client->convert_cb)(client, data0, data1, &client->nr_samples); |
| |
| if (client->nr_samples > 0) { |
| /* fire another conversion for this */ |
| |
| client->select_cb(client, 1); |
| s3c_adc_convert(adc); |
| } else { |
| spin_lock(&adc->lock); |
| (client->select_cb)(client, 0); |
| adc->cur = NULL; |
| |
| s3c_adc_try(adc); |
| spin_unlock(&adc->lock); |
| } |
| |
| exit: |
| if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3) { |
| /* Clear ADC interrupt */ |
| writel(0, adc->regs + S3C64XX_ADCCLRINT); |
| } |
| return IRQ_HANDLED; |
| } |
| |
| static int s3c_adc_probe(struct platform_device *pdev) |
| { |
| struct device *dev = &pdev->dev; |
| struct adc_device *adc; |
| enum s3c_cpu_type cpu = platform_get_device_id(pdev)->driver_data; |
| int ret; |
| unsigned tmp; |
| |
| adc = devm_kzalloc(dev, sizeof(*adc), GFP_KERNEL); |
| if (!adc) |
| return -ENOMEM; |
| |
| spin_lock_init(&adc->lock); |
| |
| adc->pdev = pdev; |
| adc->prescale = S3C2410_ADCCON_PRSCVL(49); |
| |
| adc->vdd = devm_regulator_get(dev, "vdd"); |
| if (IS_ERR(adc->vdd)) { |
| dev_err(dev, "operating without regulator \"vdd\" .\n"); |
| return PTR_ERR(adc->vdd); |
| } |
| |
| adc->irq = platform_get_irq(pdev, 1); |
| if (adc->irq <= 0) |
| return -ENOENT; |
| |
| ret = devm_request_irq(dev, adc->irq, s3c_adc_irq, 0, dev_name(dev), |
| adc); |
| if (ret < 0) { |
| dev_err(dev, "failed to attach adc irq\n"); |
| return ret; |
| } |
| |
| adc->clk = devm_clk_get(dev, "adc"); |
| if (IS_ERR(adc->clk)) { |
| dev_err(dev, "failed to get adc clock\n"); |
| return PTR_ERR(adc->clk); |
| } |
| |
| adc->regs = devm_platform_ioremap_resource(pdev, 0); |
| if (IS_ERR(adc->regs)) |
| return PTR_ERR(adc->regs); |
| |
| ret = regulator_enable(adc->vdd); |
| if (ret) |
| return ret; |
| |
| clk_prepare_enable(adc->clk); |
| |
| tmp = adc->prescale | S3C2410_ADCCON_PRSCEN; |
| |
| /* Enable 12-bit ADC resolution */ |
| if (cpu == TYPE_ADCV12) |
| tmp |= S3C2416_ADCCON_RESSEL; |
| if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3) |
| tmp |= S3C64XX_ADCCON_RESSEL; |
| |
| writel(tmp, adc->regs + S3C2410_ADCCON); |
| |
| dev_info(dev, "attached adc driver\n"); |
| |
| platform_set_drvdata(pdev, adc); |
| adc_dev = adc; |
| |
| return 0; |
| } |
| |
| static int s3c_adc_remove(struct platform_device *pdev) |
| { |
| struct adc_device *adc = platform_get_drvdata(pdev); |
| |
| clk_disable_unprepare(adc->clk); |
| regulator_disable(adc->vdd); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_PM |
| static int s3c_adc_suspend(struct device *dev) |
| { |
| struct adc_device *adc = dev_get_drvdata(dev); |
| unsigned long flags; |
| u32 con; |
| |
| spin_lock_irqsave(&adc->lock, flags); |
| |
| con = readl(adc->regs + S3C2410_ADCCON); |
| con |= S3C2410_ADCCON_STDBM; |
| writel(con, adc->regs + S3C2410_ADCCON); |
| |
| disable_irq(adc->irq); |
| spin_unlock_irqrestore(&adc->lock, flags); |
| clk_disable(adc->clk); |
| regulator_disable(adc->vdd); |
| |
| return 0; |
| } |
| |
| static int s3c_adc_resume(struct device *dev) |
| { |
| struct platform_device *pdev = to_platform_device(dev); |
| struct adc_device *adc = platform_get_drvdata(pdev); |
| enum s3c_cpu_type cpu = platform_get_device_id(pdev)->driver_data; |
| int ret; |
| unsigned long tmp; |
| |
| ret = regulator_enable(adc->vdd); |
| if (ret) |
| return ret; |
| clk_enable(adc->clk); |
| enable_irq(adc->irq); |
| |
| tmp = adc->prescale | S3C2410_ADCCON_PRSCEN; |
| |
| /* Enable 12-bit ADC resolution */ |
| if (cpu == TYPE_ADCV12) |
| tmp |= S3C2416_ADCCON_RESSEL; |
| if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3) |
| tmp |= S3C64XX_ADCCON_RESSEL; |
| |
| writel(tmp, adc->regs + S3C2410_ADCCON); |
| |
| return 0; |
| } |
| |
| #else |
| #define s3c_adc_suspend NULL |
| #define s3c_adc_resume NULL |
| #endif |
| |
| static const struct platform_device_id s3c_adc_driver_ids[] = { |
| { |
| .name = "s3c24xx-adc", |
| .driver_data = TYPE_ADCV1, |
| }, { |
| .name = "s3c2443-adc", |
| .driver_data = TYPE_ADCV11, |
| }, { |
| .name = "s3c2416-adc", |
| .driver_data = TYPE_ADCV12, |
| }, { |
| .name = "s3c64xx-adc", |
| .driver_data = TYPE_ADCV2, |
| }, { |
| .name = "samsung-adc-v3", |
| .driver_data = TYPE_ADCV3, |
| }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(platform, s3c_adc_driver_ids); |
| |
| static const struct dev_pm_ops adc_pm_ops = { |
| .suspend = s3c_adc_suspend, |
| .resume = s3c_adc_resume, |
| }; |
| |
| static struct platform_driver s3c_adc_driver = { |
| .id_table = s3c_adc_driver_ids, |
| .driver = { |
| .name = "s3c-adc", |
| .pm = &adc_pm_ops, |
| }, |
| .probe = s3c_adc_probe, |
| .remove = s3c_adc_remove, |
| }; |
| |
| static int __init adc_init(void) |
| { |
| int ret; |
| |
| ret = platform_driver_register(&s3c_adc_driver); |
| if (ret) |
| printk(KERN_ERR "%s: failed to add adc driver\n", __func__); |
| |
| return ret; |
| } |
| |
| module_init(adc_init); |