* [PATCH v2 1/2] pwm: pwm-tiecap: PWM driver support for ECAP APWM
2012-07-25 11:28 [PATCH v2 0/2] PWM driver support for EHRPWM & ECAP Philip, Avinash
@ 2012-07-25 11:28 ` Philip, Avinash
2012-07-26 7:18 ` Thierry Reding
2012-07-25 11:28 ` [PATCH v2 2/2] pwm: pwm-tiehrpwm: PWM driver support for EHRPWM Philip, Avinash
1 sibling, 1 reply; 5+ messages in thread
From: Philip, Avinash @ 2012-07-25 11:28 UTC (permalink / raw)
To: thierry.reding
Cc: linux-kernel, nsekhar, vaibhav.bedia, gururaja.hebbar,
Philip, Avinash
ECAP hardware on AM33XX SOC supports auxiliary PWM (APWM) feature. This
commit adds PWM driver support for ECAP hardware on AM33XX SOC.
In the ECAP hardware, each PWM pin can also be configured to be in
capture mode. Current implementation only supports PWM mode of
operation. Also, hardware supports sync between multiple PWM pins but
the driver supports simple independent PWM functionality.
Reviewed-by: Vaibhav Bedia <vaibhav.bedia@ti.com>
Signed-off-by: Philip, Avinash <avinashphilip@ti.com>
---
:100644 100644 94e176e... 2840747... M drivers/pwm/Kconfig
:100644 100644 5459702... 35fee43... M drivers/pwm/Makefile
:000000 100644 0000000... 3c2ad28... A drivers/pwm/pwm-tiecap.c
drivers/pwm/Kconfig | 11 ++
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-tiecap.c | 232 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 244 insertions(+), 0 deletions(-)
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 94e176e..2840747 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -76,6 +76,17 @@ config PWM_TEGRA
To compile this driver as a module, choose M here: the module
will be called pwm-tegra.
+config PWM_TIECAP
+ tristate "ECAP PWM support"
+ depends on SOC_AM33XX
+
+ help
+ PWM driver support for the ECAP APWM controller found on AM33XX
+ TI SOC
+
+ To compile this driver as a module, choose M here: the module
+ will be called pwm-tiecap.
+
config PWM_VT8500
tristate "vt8500 pwm support"
depends on ARCH_VT8500
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index 5459702..35fee43 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -6,4 +6,5 @@ obj-$(CONFIG_PWM_MXS) += pwm-mxs.o
obj-$(CONFIG_PWM_PXA) += pwm-pxa.o
obj-$(CONFIG_PWM_SAMSUNG) += pwm-samsung.o
obj-$(CONFIG_PWM_TEGRA) += pwm-tegra.o
+obj-$(CONFIG_PWM_TIECAP) += pwm-tiecap.o
obj-$(CONFIG_PWM_VT8500) += pwm-vt8500.o
diff --git a/drivers/pwm/pwm-tiecap.c b/drivers/pwm/pwm-tiecap.c
new file mode 100644
index 0000000..3c2ad28
--- /dev/null
+++ b/drivers/pwm/pwm-tiecap.c
@@ -0,0 +1,232 @@
+/*
+ * ECAP PWM driver
+ *
+ * Copyright (C) 2012 Texas Instruments, Inc. - http://www.ti.com/
+ *
+ * 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.
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/pm_runtime.h>
+#include <linux/pwm.h>
+
+/* ECAP registers and bits definitions */
+#define CAP1 0x08
+#define CAP2 0x0C
+#define CAP3 0x10
+#define CAP4 0x14
+#define ECCTL2 0x2A
+#define ECCTL2_APWM_MODE BIT(9)
+#define ECCTL2_SYNC_SEL_DISA (BIT(7) | BIT(6))
+#define ECCTL2_TSCTR_FREERUN BIT(4)
+
+struct ecap_pwm_chip {
+ struct pwm_chip chip;
+ unsigned int clk_rate;
+ void __iomem *mmio_base;
+};
+
+static inline struct ecap_pwm_chip *to_ecap_pwm_chip(struct pwm_chip *chip)
+{
+ return container_of(chip, struct ecap_pwm_chip, chip);
+}
+
+/*
+ * period_ns = 10^9 * period_cycles / PWM_CLK_RATE
+ * duty_ns = 10^9 * duty_cycles / PWM_CLK_RATE
+ */
+static int ecap_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+ int duty_ns, int period_ns)
+{
+ struct ecap_pwm_chip *pc = to_ecap_pwm_chip(chip);
+ unsigned long long c;
+ unsigned long period_cycles, duty_cycles;
+ unsigned int reg_val;
+
+ if (period_ns < 0 || duty_ns < 0 || period_ns > NSEC_PER_SEC)
+ return -ERANGE;
+
+ c = pc->clk_rate;
+ c = c * period_ns;
+ do_div(c, NSEC_PER_SEC);
+ period_cycles = (unsigned long)c;
+
+ if (period_cycles < 1) {
+ period_cycles = 1;
+ duty_cycles = 1;
+ } else {
+ c = pc->clk_rate;
+ c = c * duty_ns;
+ do_div(c, NSEC_PER_SEC);
+ duty_cycles = (unsigned long)c;
+ }
+
+ pm_runtime_get_sync(pc->chip.dev);
+
+ reg_val = readw(pc->mmio_base + ECCTL2);
+
+ /* Configure APWM mode & disable sync option */
+ reg_val |= ECCTL2_APWM_MODE | ECCTL2_SYNC_SEL_DISA;
+
+ writew(reg_val, pc->mmio_base + ECCTL2);
+
+ if (!test_bit(PWMF_ENABLED, &pwm->flags)) {
+ /* Update active registers if not running */
+ writel(duty_cycles, pc->mmio_base + CAP2);
+ writel(period_cycles, pc->mmio_base + CAP1);
+ } else {
+ /*
+ * Update shadow registers to configure period and
+ * compare values. This helps current PWM period to
+ * complete on reconfiguring
+ */
+ writel(duty_cycles, pc->mmio_base + CAP4);
+ writel(period_cycles, pc->mmio_base + CAP3);
+ }
+
+ pm_runtime_put_sync(pc->chip.dev);
+ return 0;
+}
+
+static int ecap_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct ecap_pwm_chip *pc = to_ecap_pwm_chip(chip);
+ unsigned int reg_val;
+
+ /* Leave clock enabled on enabling PWM */
+ pm_runtime_get_sync(pc->chip.dev);
+
+ /*
+ * Enable 'Free run Time stamp counter mode' to start counter
+ * and 'APWM mode' to enable APWM output
+ */
+ reg_val = readw(pc->mmio_base + ECCTL2);
+ reg_val |= ECCTL2_TSCTR_FREERUN | ECCTL2_APWM_MODE;
+ writew(reg_val, pc->mmio_base + ECCTL2);
+ return 0;
+}
+
+static void ecap_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct ecap_pwm_chip *pc = to_ecap_pwm_chip(chip);
+ unsigned int reg_val;
+
+ /*
+ * Disable 'Free run Time stamp counter mode' to stop counter
+ * and 'APWM mode' to put APWM output to low
+ */
+ reg_val = readw(pc->mmio_base + ECCTL2);
+ reg_val &= ~(ECCTL2_TSCTR_FREERUN | ECCTL2_APWM_MODE);
+ writew(reg_val, pc->mmio_base + ECCTL2);
+
+ /* Disable clock on PWM disable */
+ pm_runtime_put_sync(pc->chip.dev);
+}
+
+static void ecap_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ if (test_bit(PWMF_ENABLED, &pwm->flags)) {
+ dev_warn(chip->dev, "Removing PWM device without disabling\n");
+ pm_runtime_put_sync(chip->dev);
+ }
+}
+
+static const struct pwm_ops ecap_pwm_ops = {
+ .free = ecap_pwm_free,
+ .config = ecap_pwm_config,
+ .enable = ecap_pwm_enable,
+ .disable = ecap_pwm_disable,
+ .owner = THIS_MODULE,
+};
+
+static int __devinit ecap_pwm_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct resource *r;
+ struct clk *clk;
+ struct ecap_pwm_chip *pc;
+
+ pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
+ if (!pc) {
+ dev_err(&pdev->dev, "failed to allocate memory\n");
+ return -ENOMEM;
+ }
+
+ clk = devm_clk_get(&pdev->dev, "fck");
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "failed to get clock\n");
+ return PTR_ERR(clk);
+ }
+
+ pc->clk_rate = clk_get_rate(clk);
+ if (!pc->clk_rate) {
+ dev_err(&pdev->dev, "failed to get clock rate\n");
+ return -EINVAL;
+ }
+
+ pc->chip.dev = &pdev->dev;
+ pc->chip.ops = &ecap_pwm_ops;
+ pc->chip.base = -1;
+ pc->chip.npwm = 1;
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!r) {
+ dev_err(&pdev->dev, "no memory resource defined\n");
+ return -ENODEV;
+ }
+
+ pc->mmio_base = devm_request_and_ioremap(&pdev->dev, r);
+ if (!pc->mmio_base) {
+ dev_err(&pdev->dev, "failed to ioremap() registers\n");
+ return -EADDRNOTAVAIL;
+ }
+
+ ret = pwmchip_add(&pc->chip);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
+ return ret;
+ }
+
+ pm_runtime_enable(&pdev->dev);
+ platform_set_drvdata(pdev, pc);
+ return 0;
+}
+
+static int __devexit ecap_pwm_remove(struct platform_device *pdev)
+{
+ struct ecap_pwm_chip *pc = platform_get_drvdata(pdev);
+
+ pm_runtime_put_sync(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+ return pwmchip_remove(&pc->chip);
+}
+
+static struct platform_driver ecap_pwm_driver = {
+ .driver = {
+ .name = "ecap",
+ },
+ .probe = ecap_pwm_probe,
+ .remove = __devexit_p(ecap_pwm_remove),
+};
+
+module_platform_driver(ecap_pwm_driver);
+
+MODULE_DESCRIPTION("ECAP PWM driver");
+MODULE_AUTHOR("Texas Instruments");
+MODULE_LICENSE("GPL");
--
1.7.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH v2 2/2] pwm: pwm-tiehrpwm: PWM driver support for EHRPWM
2012-07-25 11:28 [PATCH v2 0/2] PWM driver support for EHRPWM & ECAP Philip, Avinash
2012-07-25 11:28 ` [PATCH v2 1/2] pwm: pwm-tiecap: PWM driver support for ECAP APWM Philip, Avinash
@ 2012-07-25 11:28 ` Philip, Avinash
2012-07-26 7:19 ` Thierry Reding
1 sibling, 1 reply; 5+ messages in thread
From: Philip, Avinash @ 2012-07-25 11:28 UTC (permalink / raw)
To: thierry.reding
Cc: linux-kernel, nsekhar, vaibhav.bedia, gururaja.hebbar,
Philip, Avinash
Enhanced high resolution PWM module (EHRPWM) hardware can be used to
generate PWM output over 2 channels. This commit adds PWM driver support
for EHRPWM device present on AM33XX SOC. Current implementation supports
simple PWM functionality.
Reviewed-by: Vaibhav Bedia <vaibhav.bedia@ti.com>
Signed-off-by: Philip, Avinash <avinashphilip@ti.com>
---
:100644 100644 2840747... 371a36c... M drivers/pwm/Kconfig
:100644 100644 35fee43... e4b2c89... M drivers/pwm/Makefile
:000000 100644 0000000... 010d232... A drivers/pwm/pwm-tiehrpwm.c
drivers/pwm/Kconfig | 11 ++
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-tiehrpwm.c | 411 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 423 insertions(+), 0 deletions(-)
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 2840747..371a36c 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -87,6 +87,17 @@ config PWM_TIECAP
To compile this driver as a module, choose M here: the module
will be called pwm-tiecap.
+config PWM_TIEHRPWM
+ tristate "EHRPWM PWM support"
+ depends on SOC_AM33XX
+
+ help
+ PWM driver support for the EHRPWM controller found on AM33XX
+ TI SOC
+
+ To compile this driver as a module, choose M here: the module
+ will be called pwm-tiehrpwm.
+
config PWM_VT8500
tristate "vt8500 pwm support"
depends on ARCH_VT8500
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index 35fee43..e4b2c89 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -7,4 +7,5 @@ obj-$(CONFIG_PWM_PXA) += pwm-pxa.o
obj-$(CONFIG_PWM_SAMSUNG) += pwm-samsung.o
obj-$(CONFIG_PWM_TEGRA) += pwm-tegra.o
obj-$(CONFIG_PWM_TIECAP) += pwm-tiecap.o
+obj-$(CONFIG_PWM_TIEHRPWM) += pwm-tiehrpwm.o
obj-$(CONFIG_PWM_VT8500) += pwm-vt8500.o
diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c
new file mode 100644
index 0000000..010d232
--- /dev/null
+++ b/drivers/pwm/pwm-tiehrpwm.c
@@ -0,0 +1,411 @@
+/*
+ * EHRPWM PWM driver
+ *
+ * Copyright (C) 2012 Texas Instruments, Inc. - http://www.ti.com/
+ *
+ * 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.
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/pm_runtime.h>
+
+/* EHRPWM registers and bits definitions */
+
+/* Time base module registers */
+#define TBCTL 0x00
+#define TBPRD 0x0A
+
+#define TBCTL_RUN_MASK (BIT(15) | BIT(14))
+#define TBCTL_STOP_NEXT 0
+#define TBCTL_STOP_ON_CYCLE BIT(14)
+#define TBCTL_FREE_RUN (BIT(15) | BIT(14))
+#define TBCTL_PRDLD_MASK BIT(3)
+#define TBCTL_PRDLD_SHDW 0
+#define TBCTL_PRDLD_IMDT BIT(3)
+#define TBCTL_CLKDIV_MASK (BIT(12) | BIT(11) | BIT(10) | BIT(9) | \
+ BIT(8) | BIT(7))
+#define TBCTL_CTRMODE_MASK (BIT(1) | BIT(0))
+#define TBCTL_CTRMODE_UP 0
+#define TBCTL_CTRMODE_DOWN BIT(0)
+#define TBCTL_CTRMODE_UPDOWN BIT(1)
+#define TBCTL_CTRMODE_FREEZE (BIT(1) | BIT(0))
+
+#define TBCTL_HSPCLKDIV_SHIFT 7
+#define TBCTL_CLKDIV_SHIFT 10
+
+#define CLKDIV_MAX 7
+#define HSPCLKDIV_MAX 7
+#define PERIOD_MAX 0xFFFF
+
+/* compare module registers */
+#define CMPA 0x12
+#define CMPB 0x14
+
+/* Action qualifier module registers */
+#define AQCTLA 0x16
+#define AQCTLB 0x18
+#define AQSFRC 0x1A
+#define AQCSFRC 0x1C
+
+#define AQCTL_CBU_MASK (BIT(9) | BIT(8))
+#define AQCTL_CBU_FRCLOW BIT(8)
+#define AQCTL_CBU_FRCHIGH BIT(9)
+#define AQCTL_CBU_FRCTOGGLE (BIT(9) | BIT(8))
+#define AQCTL_CAU_MASK (BIT(5) | BIT(4))
+#define AQCTL_CAU_FRCLOW BIT(4)
+#define AQCTL_CAU_FRCHIGH BIT(5)
+#define AQCTL_CAU_FRCTOGGLE (BIT(5) | BIT(4))
+#define AQCTL_PRD_MASK (BIT(3) | BIT(2))
+#define AQCTL_PRD_FRCLOW BIT(2)
+#define AQCTL_PRD_FRCHIGH BIT(3)
+#define AQCTL_PRD_FRCTOGGLE (BIT(3) | BIT(2))
+#define AQCTL_ZRO_MASK (BIT(1) | BIT(0))
+#define AQCTL_ZRO_FRCLOW BIT(0)
+#define AQCTL_ZRO_FRCHIGH BIT(1)
+#define AQCTL_ZRO_FRCTOGGLE (BIT(1) | BIT(0))
+
+#define AQSFRC_RLDCSF_MASK (BIT(7) | BIT(6))
+#define AQSFRC_RLDCSF_ZRO 0
+#define AQSFRC_RLDCSF_PRD BIT(6)
+#define AQSFRC_RLDCSF_ZROPRD BIT(7)
+#define AQSFRC_RLDCSF_IMDT (BIT(7) | BIT(6))
+
+#define AQCSFRC_CSFB_MASK (BIT(3) | BIT(2))
+#define AQCSFRC_CSFB_FRCDIS 0
+#define AQCSFRC_CSFB_FRCLOW BIT(2)
+#define AQCSFRC_CSFB_FRCHIGH BIT(3)
+#define AQCSFRC_CSFB_DISSWFRC (BIT(3) | BIT(2))
+#define AQCSFRC_CSFA_MASK (BIT(1) | BIT(0))
+#define AQCSFRC_CSFA_FRCDIS 0
+#define AQCSFRC_CSFA_FRCLOW BIT(0)
+#define AQCSFRC_CSFA_FRCHIGH BIT(1)
+#define AQCSFRC_CSFA_DISSWFRC (BIT(1) | BIT(0))
+
+#define NUM_PWM_CHANNEL 2 /* EHRPWM channels */
+
+struct ehrpwm_pwm_chip {
+ struct pwm_chip chip;
+ unsigned int clk_rate;
+ void __iomem *mmio_base;
+};
+
+static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
+{
+ return container_of(chip, struct ehrpwm_pwm_chip, chip);
+}
+
+static void ehrpwm_write(void *base, int offset, unsigned int val)
+{
+ writew(val & 0xFFFF, base + offset);
+}
+
+static void ehrpwm_modify(void *base, int offset,
+ unsigned short mask, unsigned short val)
+{
+ unsigned short regval;
+
+ regval = readw(base + offset);
+ regval &= ~mask;
+ regval |= val & mask;
+ writew(regval, base + offset);
+}
+
+/**
+ * set_prescale_div - Set up the prescaler divider function
+ * @rqst_prescaler: prescaler value min
+ * @prescale_div: prescaler value set
+ * @tb_clk_div: Time Base Control prescaler bits
+ */
+static int set_prescale_div(unsigned long rqst_prescaler,
+ unsigned short *prescale_div, unsigned short *tb_clk_div)
+{
+ unsigned int clkdiv, hspclkdiv;
+
+ for (clkdiv = 0; clkdiv <= CLKDIV_MAX; clkdiv++) {
+ for (hspclkdiv = 0; hspclkdiv <= HSPCLKDIV_MAX; hspclkdiv++) {
+
+ /*
+ * calculations for prescaler value :
+ * prescale_div = HSPCLKDIVIDER * CLKDIVIDER.
+ * HSPCLKDIVIDER = 2 ** hspclkdiv
+ * CLKDIVIDER = (1), if clkdiv == 0 *OR*
+ * (2 * clkdiv), if clkdiv != 0
+ *
+ * Configure prescale_div value such that period
+ * register value is less than 65535.
+ */
+
+ *prescale_div = (1 << clkdiv) *
+ (hspclkdiv ? (hspclkdiv * 2) : 1);
+ if (*prescale_div > rqst_prescaler) {
+ *tb_clk_div = (clkdiv << TBCTL_CLKDIV_SHIFT) |
+ (hspclkdiv << TBCTL_HSPCLKDIV_SHIFT);
+ return 0;
+ }
+ }
+ }
+ return 1;
+}
+
+static void configure_chans(struct ehrpwm_pwm_chip *pc, int chan,
+ unsigned long duty_cycles)
+{
+ int cmp_reg, aqctl_reg;
+ unsigned short aqctl_val, aqctl_mask;
+
+ /*
+ * Channels can be configured from action qualifier module.
+ * Channel 0 configured with compare A register and for
+ * up-counter mode.
+ * Channel 1 configured with compare B register and for
+ * up-counter mode.
+ */
+ if (chan == 1) {
+ aqctl_reg = AQCTLB;
+ cmp_reg = CMPB;
+ /* Configure PWM Low from compare B value */
+ aqctl_val = AQCTL_CBU_FRCLOW;
+ aqctl_mask = AQCTL_CBU_MASK;
+ } else {
+ cmp_reg = CMPA;
+ aqctl_reg = AQCTLA;
+ /* Configure PWM Low from compare A value*/
+ aqctl_val = AQCTL_CAU_FRCLOW;
+ aqctl_mask = AQCTL_CAU_MASK;
+ }
+
+ /* Configure PWM High from period value and zero value */
+ aqctl_val |= AQCTL_PRD_FRCHIGH | AQCTL_ZRO_FRCHIGH;
+ aqctl_mask |= AQCTL_PRD_MASK | AQCTL_ZRO_MASK;
+ ehrpwm_modify(pc->mmio_base, aqctl_reg, aqctl_mask, aqctl_val);
+
+ ehrpwm_write(pc->mmio_base, cmp_reg, duty_cycles);
+}
+
+/*
+ * period_ns = 10^9 * (ps_divval * period_cycles) / PWM_CLK_RATE
+ * duty_ns = 10^9 * (ps_divval * duty_cycles) / PWM_CLK_RATE
+ */
+static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+ int duty_ns, int period_ns)
+{
+ struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
+ unsigned long long c;
+ unsigned long period_cycles, duty_cycles;
+ unsigned short ps_divval, tb_divval;
+
+ if (period_ns < 0 || duty_ns < 0 || period_ns > NSEC_PER_SEC)
+ return -ERANGE;
+
+ c = pc->clk_rate;
+ c = c * period_ns;
+ do_div(c, NSEC_PER_SEC);
+ period_cycles = (unsigned long)c;
+
+ if (period_cycles < 1) {
+ period_cycles = 1;
+ duty_cycles = 1;
+ } else {
+ c = pc->clk_rate;
+ c = c * duty_ns;
+ do_div(c, NSEC_PER_SEC);
+ duty_cycles = (unsigned long)c;
+ }
+
+ /* Configure clock prescaler to support Low frequency PWM wave */
+ if (set_prescale_div(period_cycles/PERIOD_MAX, &ps_divval,
+ &tb_divval)) {
+ dev_err(chip->dev, "Unsupported values\n");
+ return -EINVAL;
+ }
+
+ pm_runtime_get_sync(chip->dev);
+
+ /* Update clock prescaler values */
+ ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CLKDIV_MASK, tb_divval);
+
+ /* Update period & duty cycle with presacler division */
+ period_cycles = period_cycles / ps_divval;
+ duty_cycles = duty_cycles / ps_divval;
+
+ /* Configure shadow loading on Period register */
+ ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_PRDLD_MASK, TBCTL_PRDLD_SHDW);
+
+ ehrpwm_write(pc->mmio_base, TBPRD, period_cycles);
+
+ /* Configure ehrpwm counter for up-count mode */
+ ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CTRMODE_MASK,
+ TBCTL_CTRMODE_UP);
+
+ /* Configure the channel for duty cycle */
+ configure_chans(pc, pwm->hwpwm, duty_cycles);
+ pm_runtime_put_sync(chip->dev);
+ return 0;
+}
+
+static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
+ unsigned short aqcsfrc_val, aqcsfrc_mask;
+
+ /* Leave clock enabled on enabling PWM */
+ pm_runtime_get_sync(chip->dev);
+
+ /* Disabling Action Qualifier on PWM output */
+ if (pwm->hwpwm) {
+ aqcsfrc_val = AQCSFRC_CSFB_FRCDIS;
+ aqcsfrc_mask = AQCSFRC_CSFB_MASK;
+ } else {
+ aqcsfrc_val = AQCSFRC_CSFA_FRCDIS;
+ aqcsfrc_mask = AQCSFRC_CSFA_MASK;
+ }
+
+ /* Changes to shadow mode */
+ ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
+ AQSFRC_RLDCSF_ZRO);
+
+ ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
+
+ /* Enable time counter for free_run */
+ ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_RUN_MASK, TBCTL_FREE_RUN);
+ return 0;
+}
+
+static void ehrpwm_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
+ unsigned short aqcsfrc_val, aqcsfrc_mask;
+
+ /* Action Qualifier puts PWM output low forcefully */
+ if (pwm->hwpwm) {
+ aqcsfrc_val = AQCSFRC_CSFB_FRCLOW;
+ aqcsfrc_mask = AQCSFRC_CSFB_MASK;
+ } else {
+ aqcsfrc_val = AQCSFRC_CSFA_FRCLOW;
+ aqcsfrc_mask = AQCSFRC_CSFA_MASK;
+ }
+
+ /*
+ * Changes to immediate action on Action Qualifier. This puts
+ * Action Qualifier control on PWM output from next TBCLK
+ */
+ ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
+ AQSFRC_RLDCSF_IMDT);
+
+ ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
+
+ /* Stop Time base counter */
+ ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_RUN_MASK, TBCTL_STOP_NEXT);
+
+ /* Disable clock on PWM disable */
+ pm_runtime_put_sync(chip->dev);
+}
+
+static void ehrpwm_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ if (test_bit(PWMF_ENABLED, &pwm->flags)) {
+ dev_warn(chip->dev, "Removing PWM device without disabling\n");
+ pm_runtime_put_sync(chip->dev);
+ }
+}
+
+static const struct pwm_ops ehrpwm_pwm_ops = {
+ .free = ehrpwm_pwm_free,
+ .config = ehrpwm_pwm_config,
+ .enable = ehrpwm_pwm_enable,
+ .disable = ehrpwm_pwm_disable,
+ .owner = THIS_MODULE,
+};
+
+static int __devinit ehrpwm_pwm_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct resource *r;
+ struct clk *clk;
+ struct ehrpwm_pwm_chip *pc;
+
+ pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
+ if (!pc) {
+ dev_err(&pdev->dev, "failed to allocate memory\n");
+ return -ENOMEM;
+ }
+
+ clk = devm_clk_get(&pdev->dev, "fck");
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "failed to get clock\n");
+ return PTR_ERR(clk);
+ }
+
+ pc->clk_rate = clk_get_rate(clk);
+ if (!pc->clk_rate) {
+ dev_err(&pdev->dev, "failed to get clock rate\n");
+ return -EINVAL;
+ }
+
+ pc->chip.dev = &pdev->dev;
+ pc->chip.ops = &ehrpwm_pwm_ops;
+ pc->chip.base = -1;
+ pc->chip.npwm = NUM_PWM_CHANNEL;
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!r) {
+ dev_err(&pdev->dev, "no memory resource defined\n");
+ return -ENODEV;
+ }
+
+ pc->mmio_base = devm_request_and_ioremap(&pdev->dev, r);
+ if (!pc->mmio_base) {
+ dev_err(&pdev->dev, "failed to ioremap() registers\n");
+ return -EADDRNOTAVAIL;
+ }
+
+ ret = pwmchip_add(&pc->chip);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
+ return ret;
+ }
+
+ pm_runtime_enable(&pdev->dev);
+ platform_set_drvdata(pdev, pc);
+ return 0;
+}
+
+static int __devexit ehrpwm_pwm_remove(struct platform_device *pdev)
+{
+ struct ehrpwm_pwm_chip *pc = platform_get_drvdata(pdev);
+
+ pm_runtime_put_sync(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+ return pwmchip_remove(&pc->chip);
+}
+
+static struct platform_driver ehrpwm_pwm_driver = {
+ .driver = {
+ .name = "ehrpwm",
+ },
+ .probe = ehrpwm_pwm_probe,
+ .remove = __devexit_p(ehrpwm_pwm_remove),
+};
+
+module_platform_driver(ehrpwm_pwm_driver);
+
+MODULE_DESCRIPTION("EHRPWM PWM driver");
+MODULE_AUTHOR("Texas Instruments");
+MODULE_LICENSE("GPL");
--
1.7.1
^ permalink raw reply related [flat|nested] 5+ messages in thread