[PATCH 2/2] soc/fsl: add ftm alarm driver for ls1021a platform
Dongsheng Wang
dongsheng.wang at freescale.com
Tue Aug 11 22:53:27 PDT 2015
From: Wang Dongsheng <dongsheng.wang at freescale.com>
Only Ftm0 can be used when system going to deep sleep. So this driver
to support ftm0 as a wakeup source.
Signed-off-by: Wang Dongsheng <dongsheng.wang at freescale.com>
---
*V2*
Change Copyright 2014 to 2015.
diff --git a/drivers/soc/fsl/ls1/Kconfig b/drivers/soc/fsl/ls1/Kconfig
index 7556f44..e6282dc 100644
--- a/drivers/soc/fsl/ls1/Kconfig
+++ b/drivers/soc/fsl/ls1/Kconfig
@@ -1,3 +1,11 @@
#
# LS-1 Soc drivers
#
+config FTM_ALARM
+ bool "FTM alarm driver"
+ depends on SOC_LS1021A
+ default n
+ help
+ Say y here to enable FTM alarm support. The FTM alarm provides
+ alarm functions for wakeup system from deep sleep. There is only
+ one FTM can be used in ALARM(FTM 0).
diff --git a/drivers/soc/fsl/ls1/Makefile b/drivers/soc/fsl/ls1/Makefile
new file mode 100644
index 0000000..6299aa1
--- /dev/null
+++ b/drivers/soc/fsl/ls1/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_FTM_ALARM) += ftm_alarm.o
diff --git a/drivers/soc/fsl/ls1/ftm_alarm.c b/drivers/soc/fsl/ls1/ftm_alarm.c
new file mode 100644
index 0000000..f7629cd
--- /dev/null
+++ b/drivers/soc/fsl/ls1/ftm_alarm.c
@@ -0,0 +1,272 @@
+/*
+ * Freescale FlexTimer Module (FTM) Alarm driver.
+ *
+ * Copyright 2015 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+
+#define FTM_SC 0x00
+#define FTM_SC_CLK_SHIFT 3
+#define FTM_SC_CLK_MASK (0x3 << FTM_SC_CLK_SHIFT)
+#define FTM_SC_CLK(c) ((c) << FTM_SC_CLK_SHIFT)
+#define FTM_SC_PS_MASK 0x7
+#define FTM_SC_TOIE BIT(6)
+#define FTM_SC_TOF BIT(7)
+
+#define FTM_SC_CLKS_FIXED_FREQ 0x02
+
+#define FTM_CNT 0x04
+#define FTM_MOD 0x08
+#define FTM_CNTIN 0x4C
+
+#define FIXED_FREQ_CLK 32000
+#define MAX_FREQ_DIV (1 << FTM_SC_PS_MASK)
+#define MAX_COUNT_VAL 0xffff
+
+static void __iomem *ftm1_base;
+static u32 alarm_freq;
+static bool big_endian;
+
+static inline u32 ftm_readl(void __iomem *addr)
+{
+ if (big_endian)
+ return ioread32be(addr);
+
+ return ioread32(addr);
+}
+
+static inline void ftm_writel(u32 val, void __iomem *addr)
+{
+ if (big_endian)
+ iowrite32be(val, addr);
+ else
+ iowrite32(val, addr);
+}
+
+static inline void ftm_counter_enable(void __iomem *base)
+{
+ u32 val;
+
+ /* select and enable counter clock source */
+ val = ftm_readl(base + FTM_SC);
+ val &= ~(FTM_SC_PS_MASK | FTM_SC_CLK_MASK);
+ val |= (FTM_SC_PS_MASK | FTM_SC_CLK(FTM_SC_CLKS_FIXED_FREQ));
+ ftm_writel(val, base + FTM_SC);
+}
+
+static inline void ftm_counter_disable(void __iomem *base)
+{
+ u32 val;
+
+ /* disable counter clock source */
+ val = ftm_readl(base + FTM_SC);
+ val &= ~(FTM_SC_PS_MASK | FTM_SC_CLK_MASK);
+ ftm_writel(val, base + FTM_SC);
+}
+
+static inline void ftm_irq_acknowledge(void __iomem *base)
+{
+ u32 val;
+
+ val = ftm_readl(base + FTM_SC);
+ val &= ~FTM_SC_TOF;
+ ftm_writel(val, base + FTM_SC);
+}
+
+static inline void ftm_irq_enable(void __iomem *base)
+{
+ u32 val;
+
+ val = ftm_readl(base + FTM_SC);
+ val |= FTM_SC_TOIE;
+ ftm_writel(val, base + FTM_SC);
+}
+
+static inline void ftm_irq_disable(void __iomem *base)
+{
+ u32 val;
+
+ val = ftm_readl(base + FTM_SC);
+ val &= ~FTM_SC_TOIE;
+ ftm_writel(val, base + FTM_SC);
+}
+
+static inline void ftm_reset_counter(void __iomem *base)
+{
+ /*
+ * The CNT register contains the FTM counter value.
+ * Reset clears the CNT register. Writing any value to COUNT
+ * updates the counter with its initial value, CNTIN.
+ */
+ ftm_writel(0x00, base + FTM_CNT);
+}
+
+static u32 time_to_cycle(unsigned long time)
+{
+ u32 cycle;
+
+ cycle = time * alarm_freq;
+ if (cycle > MAX_COUNT_VAL) {
+ pr_err("Out of alarm range.\n");
+ cycle = 0;
+ }
+
+ return cycle;
+}
+
+static u32 cycle_to_time(u32 cycle)
+{
+ return cycle / alarm_freq + 1;
+}
+
+static void ftm_clean_alarm(void)
+{
+ ftm_counter_disable(ftm1_base);
+
+ ftm_writel(0x00, ftm1_base + FTM_CNTIN);
+ ftm_writel(~0UL, ftm1_base + FTM_MOD);
+
+ ftm_reset_counter(ftm1_base);
+}
+
+static int ftm_set_alarm(u64 cycle)
+{
+ ftm_irq_disable(ftm1_base);
+
+ /*
+ * The counter increments until the value of MOD is reached,
+ * at which point the counter is reloaded with the value of CNTIN.
+ * The TOF (the overflow flag) bit is set when the FTM counter
+ * changes from MOD to CNTIN. So we should using the cycle - 1.
+ */
+ ftm_writel(cycle - 1, ftm1_base + FTM_MOD);
+
+ ftm_counter_enable(ftm1_base);
+
+ ftm_irq_enable(ftm1_base);
+
+ return 0;
+}
+
+static irqreturn_t ftm_alarm_interrupt(int irq, void *dev_id)
+{
+ ftm_irq_acknowledge(ftm1_base);
+ ftm_irq_disable(ftm1_base);
+ ftm_clean_alarm();
+
+ return IRQ_HANDLED;
+}
+
+static ssize_t ftm_alarm_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ u32 count, val;
+
+ count = ftm_readl(ftm1_base + FTM_MOD);
+ val = ftm_readl(ftm1_base + FTM_CNT);
+ val = (count & MAX_COUNT_VAL) - val;
+ val = cycle_to_time(val);
+
+ return sprintf(buf, "%u\n", val);
+}
+
+static ssize_t ftm_alarm_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ u32 cycle;
+ unsigned long time;
+
+ if (kstrtoul(buf, 0, &time))
+ return -EINVAL;
+
+ ftm_clean_alarm();
+
+ cycle = time_to_cycle(time);
+ if (!cycle)
+ return -EINVAL;
+
+ ftm_set_alarm(cycle);
+
+ return count;
+}
+
+static struct device_attribute ftm_alarm_attributes = __ATTR(ftm_alarm, 0644,
+ ftm_alarm_show, ftm_alarm_store);
+
+static int ftm_alarm_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct resource *r;
+ int irq;
+ int ret;
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!r)
+ return -ENODEV;
+
+ ftm1_base = devm_ioremap_resource(&pdev->dev, r);
+ if (IS_ERR(ftm1_base))
+ return PTR_ERR(ftm1_base);
+
+ irq = irq_of_parse_and_map(np, 0);
+ if (irq <= 0) {
+ pr_err("ftm: unable to get IRQ from DT, %d\n", irq);
+ return -EINVAL;
+ }
+
+ big_endian = of_property_read_bool(np, "big-endian");
+
+ ret = devm_request_irq(&pdev->dev, irq, ftm_alarm_interrupt,
+ IRQF_NO_SUSPEND, dev_name(&pdev->dev), NULL);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to request irq\n");
+ return ret;
+ }
+
+ ret = device_create_file(&pdev->dev, &ftm_alarm_attributes);
+ if (ret) {
+ dev_err(&pdev->dev, "create sysfs fail.\n");
+ return ret;
+ }
+
+ alarm_freq = (u32)FIXED_FREQ_CLK / (u32)MAX_FREQ_DIV;
+
+ ftm_clean_alarm();
+
+ return ret;
+}
+
+static const struct of_device_id ftm_alarm_match[] = {
+ { .compatible = "fsl,ftm-alarm", },
+ { .compatible = "fsl,ftm-timer", },
+ { },
+};
+
+static struct platform_driver ftm_alarm_driver = {
+ .probe = ftm_alarm_probe,
+ .driver = {
+ .name = "ftm-alarm",
+ .owner = THIS_MODULE,
+ .of_match_table = ftm_alarm_match,
+ },
+};
+
+static int __init ftm_alarm_init(void)
+{
+ return platform_driver_register(&ftm_alarm_driver);
+}
+device_initcall(ftm_alarm_init);
--
2.1.0.27.g96db324
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