From: Srinivas Neeli <srinivas.neeli@xilinx.com> To: <a.zummo@towertech.it>, <alexandre.belloni@bootlin.com>, <robh+dt@kernel.org>, <srinivas.neeli@amd.com>, <neelisrinivas18@gmail.com>, <krzysztof.kozlowski+dt@linaro.org>, <michal.simek@xilinx.com>, <sgoud@xilinx.com>, <shubhraj@xilinx.com> Cc: <devicetree@vger.kernel.org>, <linux-rtc@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <linux-kernel@vger.kernel.org>, <git@amd.com>, <git@xilinx.com>, Srinivas Neeli <srinivas.neeli@xilinx.com> Subject: [PATCH V10 3/3] rtc: zynqmp: Add calibration set and get support Date: Sun, 26 Jun 2022 12:38:17 +0530 [thread overview] Message-ID: <20220626070817.3780977-3-srinivas.neeli@xilinx.com> (raw) In-Reply-To: <20220626070817.3780977-1-srinivas.neeli@xilinx.com> Zynqmp RTC controller has a calibration feature to compensate time deviation due to input clock inaccuracy. Set and get calibration API's are used for setting and getting calibration value from the controller calibration register. Signed-off-by: Srinivas Neeli <srinivas.neeli@xilinx.com> --- Chanes in V10: -None Changes in V9: -None Changes in V8: -None Changes in V7: -Removed calibration default value update from this patch. Changes in V6: -None Changes in V5: -None Changes in V4: -Updated MIN and MAX calibration values. Changes in V3: -Calculated tick_mult using crystal frequency. -Calibration register updating based on crystal frequency in probe. -Supressed MIN an MAX calibration values,Will send separate patch in future. Changes in V2: -Removed unused macro. -Updated code with review comments. --- drivers/rtc/rtc-zynqmp.c | 113 ++++++++++++++++++++++++++++++++------- 1 file changed, 94 insertions(+), 19 deletions(-) diff --git a/drivers/rtc/rtc-zynqmp.c b/drivers/rtc/rtc-zynqmp.c index 5da33d760419..1dd389b891fe 100644 --- a/drivers/rtc/rtc-zynqmp.c +++ b/drivers/rtc/rtc-zynqmp.c @@ -6,6 +6,7 @@ * */ +#include <linux/clk.h> #include <linux/delay.h> #include <linux/init.h> #include <linux/io.h> @@ -40,13 +41,19 @@ #define RTC_CALIB_MASK 0x1FFFFF #define RTC_ALRM_MASK BIT(1) #define RTC_MSEC 1000 +#define RTC_FR_MASK 0xF0000 +#define RTC_FR_MAX_TICKS 16 +#define RTC_PPB 1000000000LL +#define RTC_MIN_OFFSET -32768000 +#define RTC_MAX_OFFSET 32767000 struct xlnx_rtc_dev { struct rtc_device *rtc; void __iomem *reg_base; int alarm_irq; int sec_irq; - unsigned int calibval; + struct clk *rtc_clk; + unsigned int freq; }; static int xlnx_rtc_set_time(struct device *dev, struct rtc_time *tm) @@ -61,13 +68,6 @@ static int xlnx_rtc_set_time(struct device *dev, struct rtc_time *tm) */ new_time = rtc_tm_to_time64(tm) + 1; - /* - * Writing into calibration register will clear the Tick Counter and - * force the next second to be signaled exactly in 1 second period - */ - xrtcdev->calibval &= RTC_CALIB_MASK; - writel(xrtcdev->calibval, (xrtcdev->reg_base + RTC_CALIB_WR)); - writel(new_time, xrtcdev->reg_base + RTC_SET_TM_WR); /* @@ -173,15 +173,76 @@ static void xlnx_init_rtc(struct xlnx_rtc_dev *xrtcdev) rtc_ctrl = readl(xrtcdev->reg_base + RTC_CTRL); rtc_ctrl |= RTC_BATT_EN; writel(rtc_ctrl, xrtcdev->reg_base + RTC_CTRL); +} - /* - * Based on crystal freq of 33.330 KHz - * set the seconds counter and enable, set fractions counter - * to default value suggested as per design spec - * to correct RTC delay in frequency over period of time. +static int xlnx_rtc_read_offset(struct device *dev, long *offset) +{ + struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev); + unsigned long long rtc_ppb = RTC_PPB; + unsigned int tick_mult = do_div(rtc_ppb, xrtcdev->freq); + unsigned int calibval; + long offset_val; + + calibval = readl(xrtcdev->reg_base + RTC_CALIB_RD); + /* Offset with seconds ticks */ + offset_val = calibval & RTC_TICK_MASK; + offset_val = offset_val - RTC_CALIB_DEF; + offset_val = offset_val * tick_mult; + + /* Offset with fractional ticks */ + if (calibval & RTC_FR_EN) + offset_val += ((calibval & RTC_FR_MASK) >> RTC_FR_DATSHIFT) + * (tick_mult / RTC_FR_MAX_TICKS); + *offset = offset_val; + + return 0; +} + +static int xlnx_rtc_set_offset(struct device *dev, long offset) +{ + struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev); + unsigned long long rtc_ppb = RTC_PPB; + unsigned int tick_mult = do_div(rtc_ppb, xrtcdev->freq); + unsigned char fract_tick; + unsigned int calibval; + short int max_tick; + int fract_offset; + + if (offset < RTC_MIN_OFFSET || offset > RTC_MAX_OFFSET) + return -ERANGE; + + /* Number ticks for given offset */ + max_tick = div_s64_rem(offset, tick_mult, &fract_offset); + + /* Number fractional ticks for given offset */ + if (fract_offset) { + if (fract_offset < 0) { + fract_offset = fract_offset + tick_mult; + max_tick--; + } + if (fract_offset > (tick_mult / RTC_FR_MAX_TICKS)) { + for (fract_tick = 1; fract_tick < 16; fract_tick++) { + if (fract_offset <= + (fract_tick * + (tick_mult / RTC_FR_MAX_TICKS))) + break; + } + } + } + + /* Zynqmp RTC uses second and fractional tick + * counters for compensation */ - xrtcdev->calibval &= RTC_CALIB_MASK; - writel(xrtcdev->calibval, (xrtcdev->reg_base + RTC_CALIB_WR)); + calibval = max_tick + RTC_CALIB_DEF; + + if (fract_tick) + calibval |= RTC_FR_EN; + + calibval |= (fract_tick << RTC_FR_DATSHIFT); + + writel(calibval, (xrtcdev->reg_base + RTC_CALIB_WR)); + + return 0; } static const struct rtc_class_ops xlnx_rtc_ops = { @@ -190,6 +251,8 @@ static const struct rtc_class_ops xlnx_rtc_ops = { .read_alarm = xlnx_rtc_read_alarm, .set_alarm = xlnx_rtc_set_alarm, .alarm_irq_enable = xlnx_rtc_alarm_irq_enable, + .read_offset = xlnx_rtc_read_offset, + .set_offset = xlnx_rtc_set_offset, }; static irqreturn_t xlnx_rtc_interrupt(int irq, void *id) @@ -255,10 +318,22 @@ static int xlnx_rtc_probe(struct platform_device *pdev) return ret; } - ret = of_property_read_u32(pdev->dev.of_node, "calibration", - &xrtcdev->calibval); - if (ret) - xrtcdev->calibval = RTC_CALIB_DEF; + /* Getting the rtc_clk info */ + xrtcdev->rtc_clk = devm_clk_get_optional(&pdev->dev, "rtc_clk"); + if (IS_ERR(xrtcdev->rtc_clk)) { + if (PTR_ERR(xrtcdev->rtc_clk) != -EPROBE_DEFER) + dev_warn(&pdev->dev, "Device clock not found.\n"); + } + xrtcdev->freq = clk_get_rate(xrtcdev->rtc_clk); + if (!xrtcdev->freq) { + ret = of_property_read_u32(pdev->dev.of_node, "calibration", + &xrtcdev->freq); + if (ret) + xrtcdev->freq = RTC_CALIB_DEF; + } + ret = readl(xrtcdev->reg_base + RTC_CALIB_RD); + if (!ret) + writel(xrtcdev->freq, (xrtcdev->reg_base + RTC_CALIB_WR)); xlnx_init_rtc(xrtcdev); -- 2.25.1
WARNING: multiple messages have this Message-ID (diff)
From: Srinivas Neeli <srinivas.neeli@xilinx.com> To: <a.zummo@towertech.it>, <alexandre.belloni@bootlin.com>, <robh+dt@kernel.org>, <srinivas.neeli@amd.com>, <neelisrinivas18@gmail.com>, <krzysztof.kozlowski+dt@linaro.org>, <michal.simek@xilinx.com>, <sgoud@xilinx.com>, <shubhraj@xilinx.com> Cc: <devicetree@vger.kernel.org>, <linux-rtc@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <linux-kernel@vger.kernel.org>, <git@amd.com>, <git@xilinx.com>, Srinivas Neeli <srinivas.neeli@xilinx.com> Subject: [PATCH V10 3/3] rtc: zynqmp: Add calibration set and get support Date: Sun, 26 Jun 2022 12:38:17 +0530 [thread overview] Message-ID: <20220626070817.3780977-3-srinivas.neeli@xilinx.com> (raw) In-Reply-To: <20220626070817.3780977-1-srinivas.neeli@xilinx.com> Zynqmp RTC controller has a calibration feature to compensate time deviation due to input clock inaccuracy. Set and get calibration API's are used for setting and getting calibration value from the controller calibration register. Signed-off-by: Srinivas Neeli <srinivas.neeli@xilinx.com> --- Chanes in V10: -None Changes in V9: -None Changes in V8: -None Changes in V7: -Removed calibration default value update from this patch. Changes in V6: -None Changes in V5: -None Changes in V4: -Updated MIN and MAX calibration values. Changes in V3: -Calculated tick_mult using crystal frequency. -Calibration register updating based on crystal frequency in probe. -Supressed MIN an MAX calibration values,Will send separate patch in future. Changes in V2: -Removed unused macro. -Updated code with review comments. --- drivers/rtc/rtc-zynqmp.c | 113 ++++++++++++++++++++++++++++++++------- 1 file changed, 94 insertions(+), 19 deletions(-) diff --git a/drivers/rtc/rtc-zynqmp.c b/drivers/rtc/rtc-zynqmp.c index 5da33d760419..1dd389b891fe 100644 --- a/drivers/rtc/rtc-zynqmp.c +++ b/drivers/rtc/rtc-zynqmp.c @@ -6,6 +6,7 @@ * */ +#include <linux/clk.h> #include <linux/delay.h> #include <linux/init.h> #include <linux/io.h> @@ -40,13 +41,19 @@ #define RTC_CALIB_MASK 0x1FFFFF #define RTC_ALRM_MASK BIT(1) #define RTC_MSEC 1000 +#define RTC_FR_MASK 0xF0000 +#define RTC_FR_MAX_TICKS 16 +#define RTC_PPB 1000000000LL +#define RTC_MIN_OFFSET -32768000 +#define RTC_MAX_OFFSET 32767000 struct xlnx_rtc_dev { struct rtc_device *rtc; void __iomem *reg_base; int alarm_irq; int sec_irq; - unsigned int calibval; + struct clk *rtc_clk; + unsigned int freq; }; static int xlnx_rtc_set_time(struct device *dev, struct rtc_time *tm) @@ -61,13 +68,6 @@ static int xlnx_rtc_set_time(struct device *dev, struct rtc_time *tm) */ new_time = rtc_tm_to_time64(tm) + 1; - /* - * Writing into calibration register will clear the Tick Counter and - * force the next second to be signaled exactly in 1 second period - */ - xrtcdev->calibval &= RTC_CALIB_MASK; - writel(xrtcdev->calibval, (xrtcdev->reg_base + RTC_CALIB_WR)); - writel(new_time, xrtcdev->reg_base + RTC_SET_TM_WR); /* @@ -173,15 +173,76 @@ static void xlnx_init_rtc(struct xlnx_rtc_dev *xrtcdev) rtc_ctrl = readl(xrtcdev->reg_base + RTC_CTRL); rtc_ctrl |= RTC_BATT_EN; writel(rtc_ctrl, xrtcdev->reg_base + RTC_CTRL); +} - /* - * Based on crystal freq of 33.330 KHz - * set the seconds counter and enable, set fractions counter - * to default value suggested as per design spec - * to correct RTC delay in frequency over period of time. +static int xlnx_rtc_read_offset(struct device *dev, long *offset) +{ + struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev); + unsigned long long rtc_ppb = RTC_PPB; + unsigned int tick_mult = do_div(rtc_ppb, xrtcdev->freq); + unsigned int calibval; + long offset_val; + + calibval = readl(xrtcdev->reg_base + RTC_CALIB_RD); + /* Offset with seconds ticks */ + offset_val = calibval & RTC_TICK_MASK; + offset_val = offset_val - RTC_CALIB_DEF; + offset_val = offset_val * tick_mult; + + /* Offset with fractional ticks */ + if (calibval & RTC_FR_EN) + offset_val += ((calibval & RTC_FR_MASK) >> RTC_FR_DATSHIFT) + * (tick_mult / RTC_FR_MAX_TICKS); + *offset = offset_val; + + return 0; +} + +static int xlnx_rtc_set_offset(struct device *dev, long offset) +{ + struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev); + unsigned long long rtc_ppb = RTC_PPB; + unsigned int tick_mult = do_div(rtc_ppb, xrtcdev->freq); + unsigned char fract_tick; + unsigned int calibval; + short int max_tick; + int fract_offset; + + if (offset < RTC_MIN_OFFSET || offset > RTC_MAX_OFFSET) + return -ERANGE; + + /* Number ticks for given offset */ + max_tick = div_s64_rem(offset, tick_mult, &fract_offset); + + /* Number fractional ticks for given offset */ + if (fract_offset) { + if (fract_offset < 0) { + fract_offset = fract_offset + tick_mult; + max_tick--; + } + if (fract_offset > (tick_mult / RTC_FR_MAX_TICKS)) { + for (fract_tick = 1; fract_tick < 16; fract_tick++) { + if (fract_offset <= + (fract_tick * + (tick_mult / RTC_FR_MAX_TICKS))) + break; + } + } + } + + /* Zynqmp RTC uses second and fractional tick + * counters for compensation */ - xrtcdev->calibval &= RTC_CALIB_MASK; - writel(xrtcdev->calibval, (xrtcdev->reg_base + RTC_CALIB_WR)); + calibval = max_tick + RTC_CALIB_DEF; + + if (fract_tick) + calibval |= RTC_FR_EN; + + calibval |= (fract_tick << RTC_FR_DATSHIFT); + + writel(calibval, (xrtcdev->reg_base + RTC_CALIB_WR)); + + return 0; } static const struct rtc_class_ops xlnx_rtc_ops = { @@ -190,6 +251,8 @@ static const struct rtc_class_ops xlnx_rtc_ops = { .read_alarm = xlnx_rtc_read_alarm, .set_alarm = xlnx_rtc_set_alarm, .alarm_irq_enable = xlnx_rtc_alarm_irq_enable, + .read_offset = xlnx_rtc_read_offset, + .set_offset = xlnx_rtc_set_offset, }; static irqreturn_t xlnx_rtc_interrupt(int irq, void *id) @@ -255,10 +318,22 @@ static int xlnx_rtc_probe(struct platform_device *pdev) return ret; } - ret = of_property_read_u32(pdev->dev.of_node, "calibration", - &xrtcdev->calibval); - if (ret) - xrtcdev->calibval = RTC_CALIB_DEF; + /* Getting the rtc_clk info */ + xrtcdev->rtc_clk = devm_clk_get_optional(&pdev->dev, "rtc_clk"); + if (IS_ERR(xrtcdev->rtc_clk)) { + if (PTR_ERR(xrtcdev->rtc_clk) != -EPROBE_DEFER) + dev_warn(&pdev->dev, "Device clock not found.\n"); + } + xrtcdev->freq = clk_get_rate(xrtcdev->rtc_clk); + if (!xrtcdev->freq) { + ret = of_property_read_u32(pdev->dev.of_node, "calibration", + &xrtcdev->freq); + if (ret) + xrtcdev->freq = RTC_CALIB_DEF; + } + ret = readl(xrtcdev->reg_base + RTC_CALIB_RD); + if (!ret) + writel(xrtcdev->freq, (xrtcdev->reg_base + RTC_CALIB_WR)); xlnx_init_rtc(xrtcdev); -- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-06-26 7:09 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-06-26 7:08 [PATCH V10 1/3] dt-bindings: rtc: zynqmp: Add clock information Srinivas Neeli 2022-06-26 7:08 ` Srinivas Neeli 2022-06-26 7:08 ` [PATCH V10 2/3] rtc: zynqmp: Updated calibration value Srinivas Neeli 2022-06-26 7:08 ` Srinivas Neeli 2022-06-26 7:08 ` Srinivas Neeli [this message] 2022-06-26 7:08 ` [PATCH V10 3/3] rtc: zynqmp: Add calibration set and get support Srinivas Neeli 2022-07-22 15:23 ` Neeli, Srinivas 2022-07-22 15:23 ` Neeli, Srinivas 2022-06-26 10:36 ` [PATCH V10 1/3] dt-bindings: rtc: zynqmp: Add clock information Krzysztof Kozlowski 2022-06-26 10:36 ` Krzysztof Kozlowski 2022-07-26 9:22 ` Alexandre Belloni 2022-07-26 9:22 ` Alexandre Belloni
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