From: Fenglin Wu <fengl...@codeaurora.org>

Add pwm_chip to support QTI LPG module and export LPG channels as
PWM devices for consumer drivers' usage.

Signed-off-by: Fenglin Wu <fengl...@codeaurora.org>
---
 .../devicetree/bindings/pwm/pwm-qti-lpg.txt        |  39 ++
 drivers/pwm/Kconfig                                |  10 +
 drivers/pwm/Makefile                               |   1 +
 drivers/pwm/pwm-qti-lpg.c                          | 578 +++++++++++++++++++++
 4 files changed, 628 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/pwm-qti-lpg.txt
 create mode 100644 drivers/pwm/pwm-qti-lpg.c

diff --git a/Documentation/devicetree/bindings/pwm/pwm-qti-lpg.txt 
b/Documentation/devicetree/bindings/pwm/pwm-qti-lpg.txt
new file mode 100644
index 0000000..df81f5f
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/pwm-qti-lpg.txt
@@ -0,0 +1,39 @@
+Qualcomm Technologies, Inc. LPG driver specific bindings
+
+This binding document describes the properties of LPG (Light Pulse Generator)
+device module in Qualcomm Technologies, Inc. PMIC chips.
+
+- compatible:
+       Usage: required
+       Value type: <string>
+       Definition: Must be "qcom,pwm-lpg".
+
+- reg:
+       Usage: required
+       Value type: <prop-encoded-array>
+       Definition: Register base and length for LPG modules. The length
+                     varies based on the number of channels available in
+                     the PMIC chips.
+
+- reg-names:
+       Usage: required
+       Value type: <string>
+       Definition: The name of the register defined in the reg property.
+                     It must be "lpg-base".
+
+- #pwm-cells:
+       Usage: required
+       Value type: <u32>
+       Definition: The number of cells in "pwms" property specified in
+                     PWM user nodes. It should be 2. The first cell is
+                     the PWM channel ID indexed from 0, and the second
+                     cell is the PWM default period in nanoseconds.
+
+Example:
+
+       pmi8998_lpg: lpg@b100 {
+               compatible = "qcom,pwm-lpg";
+               reg = <0xb100 0x600>;
+               reg-names = "lpg-base";
+               #pwm-cells = <2>;
+       };
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 313c107..711104f 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -349,6 +349,16 @@ config PWM_PXA
          To compile this driver as a module, choose M here: the module
          will be called pwm-pxa.
 
+config PWM_QTI_LPG
+       tristate "Qualcomm Technologies, Inc. LPG driver"
+       depends on  MFD_SPMI_PMIC && OF
+       help
+         This driver supports the LPG (Light Pulse Generator) module found in
+         Qualcomm Technologies, Inc. PMIC chips. Each LPG channel can be
+         configured to operate in PWM mode to output a fixed amplitude with
+         variable duty cycle or in LUT (Look up table) mode to output PWM
+         signal with a modulated amplitude.
+
 config PWM_RCAR
        tristate "Renesas R-Car PWM support"
        depends on ARCH_RENESAS || COMPILE_TEST
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index 93da1f7..16958be 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -33,6 +33,7 @@ obj-$(CONFIG_PWM_OMAP_DMTIMER)        += pwm-omap-dmtimer.o
 obj-$(CONFIG_PWM_PCA9685)      += pwm-pca9685.o
 obj-$(CONFIG_PWM_PUV3)         += pwm-puv3.o
 obj-$(CONFIG_PWM_PXA)          += pwm-pxa.o
+obj-$(CONFIG_PWM_QTI_LPG)      += pwm-qti-lpg.o
 obj-$(CONFIG_PWM_RCAR)         += pwm-rcar.o
 obj-$(CONFIG_PWM_RENESAS_TPU)  += pwm-renesas-tpu.o
 obj-$(CONFIG_PWM_ROCKCHIP)     += pwm-rockchip.o
diff --git a/drivers/pwm/pwm-qti-lpg.c b/drivers/pwm/pwm-qti-lpg.c
new file mode 100644
index 0000000..929b6a4
--- /dev/null
+++ b/drivers/pwm/pwm-qti-lpg.c
@@ -0,0 +1,578 @@
+/* Copyright (c) 2017, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+#define REG_SIZE_PER_LPG       0x100
+
+#define REG_LPG_PWM_SIZE_CLK           0x41
+#define REG_LPG_PWM_FREQ_PREDIV_CLK    0x42
+#define REG_LPG_PWM_TYPE_CONFIG                0x43
+#define REG_LPG_PWM_VALUE_LSB          0x44
+#define REG_LPG_PWM_VALUE_MSB          0x45
+#define REG_LPG_ENABLE_CONTROL         0x46
+#define REG_LPG_PWM_SYNC               0x47
+
+/* REG_LPG_PWM_SIZE_CLK */
+#define LPG_PWM_SIZE_MASK              BIT(4)
+#define LPG_PWM_SIZE_SHIFT             4
+#define LPG_PWM_CLK_FREQ_SEL_MASK      GENMASK(1, 0)
+
+/* REG_LPG_PWM_FREQ_PREDIV_CLK */
+#define LPG_PWM_FREQ_PREDIV_MASK       GENMASK(6, 5)
+#define LPG_PWM_FREQ_PREDIV_SHIFT      5
+#define LPG_PWM_FREQ_EXPONENT_MASK     GENMASK(2, 0)
+
+/* REG_LPG_PWM_TYPE_CONFIG */
+#define LPG_PWM_EN_GLITCH_REMOVAL_MASK BIT(5)
+
+/* REG_LPG_PWM_VALUE_LSB */
+#define LPG_PWM_VALUE_LSB_MASK         GENMASK(7, 0)
+
+/* REG_LPG_PWM_VALUE_MSB */
+#define LPG_PWM_VALUE_MSB_MASK         BIT(0)
+
+/* REG_LPG_ENABLE_CONTROL */
+#define LPG_EN_LPG_OUT_BIT             BIT(7)
+#define LPG_PWM_SRC_SELECT_MASK                BIT(2)
+#define LPG_PWM_SRC_SELECT_SHIFT       2
+#define LPG_EN_RAMP_GEN_MASK           BIT(1)
+#define LPG_EN_RAMP_GEN_SHIFT          1
+
+/* REG_LPG_PWM_SYNC */
+#define LPG_PWM_VALUE_SYNC             BIT(0)
+
+#define NUM_PWM_SIZE                   2
+#define NUM_PWM_CLK                    3
+#define NUM_CLK_PREDIV                 4
+#define NUM_PWM_EXP                    8
+
+enum {
+       LUT_PATTERN = 0,
+       PWM_OUTPUT,
+};
+
+static const int pwm_size[NUM_PWM_SIZE] = {6, 9};
+static const int clk_freq_hz[NUM_PWM_CLK] = {1024, 32768, 19200000};
+static const int clk_prediv[NUM_CLK_PREDIV] = {1, 3, 5, 6};
+static const int pwm_exponent[NUM_PWM_EXP] = {0, 1, 2, 3, 4, 5, 6, 7};
+
+struct lpg_pwm_config {
+       u32     pwm_size;
+       u32     pwm_clk;
+       u32     prediv;
+       u32     clk_exp;
+       u16     pwm_value;
+       u32     best_period_ns;
+};
+
+struct qti_lpg_channel {
+       struct qti_lpg_chip             *chip;
+       struct lpg_pwm_config           pwm_config;
+       u32                             lpg_idx;
+       u32                             reg_base;
+       u8                              src_sel;
+       int                             current_period_ns;
+       int                             current_duty_ns;
+};
+
+struct qti_lpg_chip {
+       struct pwm_chip         pwm_chip;
+       struct regmap           *regmap;
+       struct device           *dev;
+       struct qti_lpg_channel  *lpgs;
+       struct mutex            bus_lock;
+       u32                     lpg_nums;
+};
+
+static int qti_lpg_write(struct qti_lpg_channel *lpg, u16 addr, u8 val)
+{
+       int rc;
+
+       mutex_lock(&lpg->chip->bus_lock);
+       rc = regmap_write(lpg->chip->regmap, lpg->reg_base + addr, val);
+       if (rc < 0)
+               dev_err(lpg->chip->dev, "Write addr 0x%x with value %d failed, 
rc=%d\n",
+                               lpg->reg_base + addr, val, rc);
+       mutex_unlock(&lpg->chip->bus_lock);
+
+       return rc;
+}
+
+static int qti_lpg_masked_write(struct qti_lpg_channel *lpg,
+                               u16 addr, u8 mask, u8 val)
+{
+       int rc;
+
+       mutex_lock(&lpg->chip->bus_lock);
+       rc = regmap_update_bits(lpg->chip->regmap, lpg->reg_base + addr,
+                                                       mask, val);
+       if (rc < 0)
+               dev_err(lpg->chip->dev, "Update addr 0x%x to val 0x%x with mask 
0x%x failed, rc=%d\n",
+                               lpg->reg_base + addr, val, mask, rc);
+       mutex_unlock(&lpg->chip->bus_lock);
+
+       return rc;
+}
+
+static struct qti_lpg_channel *pwm_dev_to_qti_lpg(struct pwm_chip *pwm_chip,
+                               struct pwm_device *pwm) {
+
+       struct qti_lpg_chip *chip = container_of(pwm_chip,
+                       struct qti_lpg_chip, pwm_chip);
+       u32 hw_idx = pwm->hwpwm;
+
+       if (hw_idx >= chip->lpg_nums) {
+               dev_err(chip->dev, "hw index %d out of range [0-%d]\n",
+                               hw_idx, chip->lpg_nums - 1);
+               return NULL;
+       }
+
+       return &chip->lpgs[hw_idx];
+}
+
+static int __find_index_in_array(int member, const int array[], int length)
+{
+       int i;
+
+       for (i = 0; i < length; i++) {
+               if (member == array[i])
+                       return i;
+       }
+
+       return -EINVAL;
+}
+
+static int qti_lpg_set_pwm_config(struct qti_lpg_channel *lpg)
+{
+       int rc;
+       u8 val, mask;
+       int pwm_size_idx, pwm_clk_idx, prediv_idx, clk_exp_idx;
+
+       pwm_size_idx = __find_index_in_array(lpg->pwm_config.pwm_size,
+                       pwm_size, ARRAY_SIZE(pwm_size));
+       pwm_clk_idx = __find_index_in_array(lpg->pwm_config.pwm_clk,
+                       clk_freq_hz, ARRAY_SIZE(clk_freq_hz));
+       prediv_idx = __find_index_in_array(lpg->pwm_config.prediv,
+                       clk_prediv, ARRAY_SIZE(clk_prediv));
+       clk_exp_idx = __find_index_in_array(lpg->pwm_config.clk_exp,
+                       pwm_exponent, ARRAY_SIZE(pwm_exponent));
+
+       if (pwm_size_idx < 0 || pwm_clk_idx < 0
+                       || prediv_idx < 0 || clk_exp_idx < 0)
+               return -EINVAL;
+
+       pwm_clk_idx += 1;
+       val = pwm_size_idx << LPG_PWM_SIZE_SHIFT | pwm_clk_idx;
+       mask = LPG_PWM_SIZE_MASK | LPG_PWM_CLK_FREQ_SEL_MASK;
+       rc = qti_lpg_masked_write(lpg, REG_LPG_PWM_SIZE_CLK, mask, val);
+       if (rc < 0) {
+               dev_err(lpg->chip->dev, "Write LPG_PWM_SIZE_CLK failed, 
rc=%d\n",
+                                                       rc);
+               return rc;
+       }
+
+       val = prediv_idx << LPG_PWM_FREQ_PREDIV_SHIFT | clk_exp_idx;
+       mask = LPG_PWM_FREQ_PREDIV_MASK | LPG_PWM_FREQ_EXPONENT_MASK;
+       rc = qti_lpg_masked_write(lpg, REG_LPG_PWM_FREQ_PREDIV_CLK, mask, val);
+       if (rc < 0) {
+               dev_err(lpg->chip->dev, "Write LPG_PWM_FREQ_PREDIV_CLK failed, 
rc=%d\n",
+                                                       rc);
+               return rc;
+       }
+
+       val = lpg->pwm_config.pwm_value & LPG_PWM_VALUE_LSB_MASK;
+       rc = qti_lpg_write(lpg, REG_LPG_PWM_VALUE_LSB, val);
+       if (rc < 0) {
+               dev_err(lpg->chip->dev, "Write LPG_PWM_VALUE_LSB failed, 
rc=%d\n",
+                                                       rc);
+               return rc;
+       }
+
+       val = lpg->pwm_config.pwm_value >> 8;
+       mask = LPG_PWM_VALUE_MSB_MASK;
+       rc = qti_lpg_masked_write(lpg, REG_LPG_PWM_VALUE_MSB, mask, val);
+       if (rc < 0) {
+               dev_err(lpg->chip->dev, "Write LPG_PWM_VALUE_MSB failed, 
rc=%d\n",
+                                                       rc);
+               return rc;
+       }
+
+       val = LPG_PWM_VALUE_SYNC;
+       rc = qti_lpg_write(lpg, REG_LPG_PWM_SYNC, val);
+       if (rc < 0) {
+               dev_err(lpg->chip->dev, "Write LPG_PWM_SYNC failed, rc=%d\n",
+                                                       rc);
+               return rc;
+       }
+
+       return rc;
+}
+
+static void __qti_lpg_calc_pwm_period(int period_ns,
+                       struct lpg_pwm_config *pwm_config)
+{
+       struct lpg_pwm_config configs[NUM_PWM_SIZE];
+       int i, j, m, n;
+       int tmp1, tmp2;
+       int clk_period_ns = 0, pwm_clk_period_ns;
+       int clk_delta_ns = INT_MAX, min_clk_delta_ns = INT_MAX;
+       int pwm_period_delta = INT_MAX, min_pwm_period_delta = INT_MAX;
+       int pwm_size_step;
+
+       /*
+        *              (2^pwm_size) * (2^pwm_exp) * prediv * NSEC_PER_SEC
+        * pwm_period = ---------------------------------------------------
+        *                               clk_freq_hz
+        *
+        * Searching the closest settings for the requested PWM period.
+        */
+       for (n = 0; n < ARRAY_SIZE(pwm_size); n++) {
+               pwm_clk_period_ns = period_ns >> pwm_size[n];
+               for (i = ARRAY_SIZE(clk_freq_hz) - 1; i >= 0; i--) {
+                       for (j = 0; j < ARRAY_SIZE(clk_prediv); j++) {
+                               for (m = 0; m < ARRAY_SIZE(pwm_exponent); m++) {
+                                       tmp1 = 1 << pwm_exponent[m];
+                                       tmp1 *= clk_prediv[j];
+                                       tmp2 = NSEC_PER_SEC / clk_freq_hz[i];
+
+                                       clk_period_ns = tmp1 * tmp2;
+
+                                       clk_delta_ns = abs(pwm_clk_period_ns
+                                               - clk_period_ns);
+                                       /*
+                                        * Find the closet setting for
+                                        * PWM frequency predivide value
+                                        */
+                                       if (clk_delta_ns < min_clk_delta_ns) {
+                                               min_clk_delta_ns
+                                                       = clk_delta_ns;
+                                               configs[n].pwm_clk
+                                                       = clk_freq_hz[i];
+                                               configs[n].prediv
+                                                       = clk_prediv[j];
+                                               configs[n].clk_exp
+                                                       = pwm_exponent[m];
+                                               configs[n].pwm_size
+                                                       = pwm_size[n];
+                                               configs[n].best_period_ns
+                                                       = clk_period_ns;
+                                       }
+                               }
+                       }
+               }
+               configs[n].best_period_ns *= 1 << pwm_size[n];
+               /* Find the closet setting for PWM period */
+               pwm_period_delta = min_clk_delta_ns << pwm_size[n];
+               if (pwm_period_delta < min_pwm_period_delta) {
+                       min_pwm_period_delta = pwm_period_delta;
+                       memcpy(pwm_config, &configs[n],
+                                       sizeof(struct lpg_pwm_config));
+               }
+       }
+
+       /* Larger PWM size can achieve better resolution for PWM duty */
+       for (n = ARRAY_SIZE(pwm_size) - 1; n > 0; n--) {
+               if (pwm_config->pwm_size >= pwm_size[n])
+                       break;
+               pwm_size_step = pwm_size[n] - pwm_config->pwm_size;
+               if (pwm_config->clk_exp >= pwm_size_step) {
+                       pwm_config->pwm_size = pwm_size[n];
+                       pwm_config->clk_exp -= pwm_size_step;
+               }
+       }
+       pr_debug("PWM setting for period_ns %d: pwm_clk = %dHZ, prediv = %d, 
exponent = %d, pwm_size = %d\n",
+                       period_ns, pwm_config->pwm_clk, pwm_config->prediv,
+                       pwm_config->clk_exp, pwm_config->pwm_size);
+       pr_debug("Actual period: %dns\n", pwm_config->best_period_ns);
+}
+
+static void __qti_lpg_calc_pwm_duty(int period_ns, int duty_ns,
+                       struct lpg_pwm_config *pwm_config)
+{
+       u16 pwm_value, max_pwm_value;
+
+       if ((1 << pwm_config->pwm_size) > (INT_MAX / duty_ns))
+               pwm_value = duty_ns / (period_ns >> pwm_config->pwm_size);
+       else
+               pwm_value = (duty_ns << pwm_config->pwm_size) / period_ns;
+
+       max_pwm_value = (1 << pwm_config->pwm_size) - 1;
+       if (pwm_value > max_pwm_value)
+               pwm_value = max_pwm_value;
+       pwm_config->pwm_value = pwm_value;
+}
+
+static int qti_lpg_pwm_config(struct pwm_chip *pwm_chip,
+               struct pwm_device *pwm, int duty_ns, int period_ns)
+{
+       struct qti_lpg_channel *lpg;
+       int rc = 0;
+
+       lpg = pwm_dev_to_qti_lpg(pwm_chip, pwm);
+       if (lpg == NULL) {
+               dev_err(pwm_chip->dev, "lpg not found\n");
+               return -ENODEV;
+       }
+
+       if (duty_ns > period_ns) {
+               dev_err(pwm_chip->dev, "Duty %dns is larger than period %dns\n",
+                                               duty_ns, period_ns);
+               return -EINVAL;
+       }
+
+       if (period_ns != lpg->current_period_ns)
+               __qti_lpg_calc_pwm_period(period_ns, &lpg->pwm_config);
+
+       if (period_ns != lpg->current_period_ns ||
+                       duty_ns != lpg->current_duty_ns)
+               __qti_lpg_calc_pwm_duty(period_ns, duty_ns, &lpg->pwm_config);
+
+       rc = qti_lpg_set_pwm_config(lpg);
+       if (rc < 0)
+               dev_err(pwm_chip->dev, "Config PWM failed for channel %d, 
rc=%d\n",
+                                               lpg->lpg_idx, rc);
+
+       return rc;
+}
+
+static int qti_lpg_pwm_enable(struct pwm_chip *pwm_chip,
+                               struct pwm_device *pwm)
+{
+       struct qti_lpg_channel *lpg;
+       int rc = 0;
+       u8 mask, val;
+
+       lpg = pwm_dev_to_qti_lpg(pwm_chip, pwm);
+       if (lpg == NULL) {
+               dev_err(pwm_chip->dev, "lpg not found\n");
+               return -ENODEV;
+       }
+
+       mask = LPG_PWM_SRC_SELECT_MASK | LPG_EN_LPG_OUT_BIT;
+
+       val = lpg->src_sel << LPG_PWM_SRC_SELECT_SHIFT | LPG_EN_LPG_OUT_BIT;
+
+       rc = qti_lpg_masked_write(lpg, REG_LPG_ENABLE_CONTROL, mask, val);
+       if (rc < 0)
+               dev_err(pwm_chip->dev, "Enable PWM output failed for channel 
%d, rc=%d\n",
+                                               lpg->lpg_idx, rc);
+
+       return rc;
+}
+
+static void qti_lpg_pwm_disable(struct pwm_chip *pwm_chip,
+                               struct pwm_device *pwm)
+{
+       struct qti_lpg_channel *lpg;
+       int rc;
+       u8 mask, val;
+
+       lpg = pwm_dev_to_qti_lpg(pwm_chip, pwm);
+       if (lpg == NULL) {
+               dev_err(pwm_chip->dev, "lpg not found\n");
+               return;
+       }
+
+       mask = LPG_PWM_SRC_SELECT_MASK | LPG_EN_LPG_OUT_BIT;
+
+       val = lpg->src_sel << LPG_PWM_SRC_SELECT_SHIFT;
+
+       rc = qti_lpg_masked_write(lpg, REG_LPG_ENABLE_CONTROL, mask, val);
+       if (rc < 0)
+               dev_err(pwm_chip->dev, "Disable PWM output failed for channel 
%d, rc=%d\n",
+                                               lpg->lpg_idx, rc);
+}
+
+#ifdef CONFIG_DEBUG_FS
+static void qti_lpg_pwm_dbg_show(struct pwm_chip *pwm_chip, struct seq_file *s)
+{
+       struct qti_lpg_channel *lpg;
+       struct lpg_pwm_config *cfg;
+       struct pwm_device *pwm;
+       int i;
+
+       for (i = 0; i < pwm_chip->npwm; i++) {
+               pwm = &pwm_chip->pwms[i];
+
+               lpg = pwm_dev_to_qti_lpg(pwm_chip, pwm);
+               if (lpg == NULL) {
+                       dev_err(pwm_chip->dev, "lpg not found\n");
+                       return;
+               }
+
+               if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
+                       seq_printf(s, "LPG %d is requested by %s\n",
+                                       lpg->lpg_idx + 1, pwm->label);
+               } else {
+                       seq_printf(s, "LPG %d is free\n",
+                                       lpg->lpg_idx + 1);
+                       continue;
+               }
+
+               if (pwm_is_enabled(pwm)) {
+                       seq_puts(s, "  enabled\n");
+               } else {
+                       seq_puts(s, "  disabled\n");
+                       continue;
+               }
+
+               cfg = &lpg->pwm_config;
+               seq_printf(s, "     clk = %dHz\n", cfg->pwm_clk);
+               seq_printf(s, "     pwm_size = %d\n", cfg->pwm_size);
+               seq_printf(s, "     prediv = %d\n", cfg->prediv);
+               seq_printf(s, "     exponent = %d\n", cfg->clk_exp);
+               seq_printf(s, "     pwm_value = %d\n", cfg->pwm_value);
+               seq_printf(s, "  Requested period: %dns, best period = %dns\n",
+                               pwm_get_period(pwm), cfg->best_period_ns);
+       }
+}
+#endif
+
+static const struct pwm_ops qti_lpg_pwm_ops = {
+       .config = qti_lpg_pwm_config,
+       .enable = qti_lpg_pwm_enable,
+       .disable = qti_lpg_pwm_disable,
+#ifdef CONFIG_DEBUG_FS
+       .dbg_show = qti_lpg_pwm_dbg_show,
+#endif
+       .owner = THIS_MODULE,
+};
+
+static int qti_lpg_add_pwmchip(struct qti_lpg_chip *chip)
+{
+       int rc;
+
+       chip->pwm_chip.dev = chip->dev;
+       chip->pwm_chip.base = -1;
+       chip->pwm_chip.npwm = chip->lpg_nums;
+       chip->pwm_chip.ops = &qti_lpg_pwm_ops;
+
+       rc = pwmchip_add(&chip->pwm_chip);
+       if (rc < 0)
+               dev_err(chip->dev, "Add pwmchip failed, rc=%d\n", rc);
+
+       return rc;
+}
+
+static int qti_lpg_parse_dt(struct qti_lpg_chip *chip)
+{
+       int rc = 0, i;
+       u64 base, length;
+       const __be32 *addr;
+
+       addr = of_get_address(chip->dev->of_node, 0, NULL, NULL);
+       if (!addr) {
+               dev_err(chip->dev, "Getting address failed\n");
+               return -EINVAL;
+       }
+       base = be32_to_cpu(addr[0]);
+       length = be32_to_cpu(addr[1]);
+
+       chip->lpg_nums = length / REG_SIZE_PER_LPG;
+       chip->lpgs = devm_kcalloc(chip->dev, chip->lpg_nums,
+                       sizeof(*chip->lpgs), GFP_KERNEL);
+       if (!chip->lpgs)
+               return -ENOMEM;
+
+       for (i = 0; i < chip->lpg_nums; i++) {
+               chip->lpgs[i].chip = chip;
+               chip->lpgs[i].lpg_idx = i;
+               chip->lpgs[i].reg_base = base + i * REG_SIZE_PER_LPG;
+               chip->lpgs[i].src_sel = PWM_OUTPUT;
+       }
+
+       return rc;
+}
+
+static int qti_lpg_probe(struct platform_device *pdev)
+{
+       int rc;
+       struct qti_lpg_chip *chip;
+
+       chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
+       if (!chip)
+               return -ENOMEM;
+
+       chip->dev = &pdev->dev;
+       chip->regmap = dev_get_regmap(chip->dev->parent, NULL);
+       if (!chip->regmap) {
+               dev_err(chip->dev, "Getting regmap failed\n");
+               return -EINVAL;
+       }
+
+       rc = qti_lpg_parse_dt(chip);
+       if (rc < 0) {
+               dev_err(chip->dev, "Devicetree properties parsing failed, 
rc=%d\n",
+                               rc);
+               return rc;
+       }
+
+       dev_set_drvdata(chip->dev, chip);
+
+       mutex_init(&chip->bus_lock);
+       rc = qti_lpg_add_pwmchip(chip);
+       if (rc < 0) {
+               dev_err(chip->dev, "Add pwmchip failed, rc=%d\n", rc);
+               mutex_destroy(&chip->bus_lock);
+       }
+
+       return rc;
+}
+
+static int qti_lpg_remove(struct platform_device *pdev)
+{
+       struct qti_lpg_chip *chip = dev_get_drvdata(&pdev->dev);
+       int rc = 0;
+
+       rc = pwmchip_remove(&chip->pwm_chip);
+       if (rc < 0)
+               dev_err(chip->dev, "Remove pwmchip failed, rc=%d\n", rc);
+
+       mutex_destroy(&chip->bus_lock);
+       dev_set_drvdata(chip->dev, NULL);
+
+       return rc;
+}
+
+static const struct of_device_id qti_lpg_of_match[] = {
+       { .compatible = "qcom,pwm-lpg",},
+       { },
+};
+
+static struct platform_driver qti_lpg_driver = {
+       .driver         = {
+               .name           = "qcom,pwm-lpg",
+               .of_match_table = qti_lpg_of_match,
+       },
+       .probe          = qti_lpg_probe,
+       .remove         = qti_lpg_remove,
+};
+module_platform_driver(qti_lpg_driver);
+
+MODULE_DESCRIPTION("QTI LPG driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("pwm:pwm-lpg");
-- 
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.

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