bananarchy/src/leds-msm8905-torch/leds-msm8905-torch.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Qualcomm MSM8905 / Nokia 8110 4G (nokia-argon) SY7807 Rear Flashlight Driver
 *
 * Drives the SY7807 boost LED controller on TLMM GPIO_32 (cci_timer1) using
 * GCC camss_gp1_clk_src at 150 kHz (50% duty cycle in continuous Torch mode),
 * matching the hardware sequence from the stock Nokia 8110 4G kernel.
 */

#include <linux/delay.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/regmap.h>
#include <linux/spinlock.h>

#define MSM8905_TLMM_GPIO32_PHYS  0x01020000UL
#define MSM8905_TLMM_GPIO32_SIZE  0x1000UL
#define GPIO32_CFG_REG            0x0000U
#define GPIO32_CFG_CCI_TIMER1     0x0008U /* 2mA, no pull, func=2 (cci_timer1) */
#define GPIO32_CFG_GPIO_OFF       0x0001U /* 2mA, pull-down, func=0 (gpio in) */

#define MSM8905_GCC_CAMSS_PHYS    0x01850000UL
#define MSM8905_GCC_CAMSS_SIZE    0x6000UL
#define GCC_CAMSS_GP1_CBCR_STOCK  0x0004U /* Stock MSM8909 gcc_camss_gp1_clk CBCR */
#define GCC_CAMSS_GP1_CMD_RCGR    0x5000U /* camss_gp1_clk_src CMD_RCGR */
#define GCC_CAMSS_GP1_CFG_RCGR    0x5004U /* camss_gp1_clk_src CFG_RCGR */
#define GCC_CAMSS_GP1_M_REG       0x5008U /* M = 1 */
#define GCC_CAMSS_GP1_N_REG       0x500cU /* ~(128 - 1) = 0xff80 (19.2MHz / 128 = 150kHz) */
#define GCC_CAMSS_GP1_D_REG       0x5010U /* ~128 = 0xff7f (50% duty cycle) */
#define GCC_CAMSS_GP1_CBCR_MAIN   0x5018U /* Mainline gcc_camss_gp1_clk CBCR */

#define RCGR_CFG_150KHZ_XO        0x2001U /* Dual-edge M/N:D (mode=2), XO (src=0), div=1 */
#define RCGR_M_150KHZ             0x0001U
#define RCGR_N_150KHZ             0xff80U
#define RCGR_D_TORCH_50PCT        0xff7fU
#define RCGR_CMD_ENABLE_UPDATE    0x0003U /* ROOT_EN | CMD_UPDATE */

/* PM8909 PON registers for PS_HOLD shutdown vs warm reset configuration */
#define QPNP_PON_PS_HOLD_RST_CTL   0x085aU
#define QPNP_PON_PS_HOLD_RST_CTL2  0x085bU
#define QPNP_PON_S2_CNTL_EN        0x80U
#define QPNP_PON_RST_TYPE_MASK     0x0fU
#define PON_POWER_OFF_WARM_RESET   0x01U
#define PON_POWER_OFF_SHUTDOWN     0x04U
#define PON_POWER_OFF_HARD_RESET   0x07U

static void __iomem *tlmm_gpio32_base;
static void __iomem *gcc_camss_base;
static struct regmap *pon_regmap;
static DEFINE_SPINLOCK(torch_lock);
static enum led_brightness current_brightness = LED_OFF;

static void msm8905_torch_hw_enable(enum led_brightness value)
{
  unsigned long flags;
  u32 d_count;
  u32 d_reg;

  /*
   * Scale PWM duty cycle up to 50% (d_count = 64 of N = 128) at max brightness
   * so the SY7807 remains in continuous Torch mode without triggering its
   * high-current Flash Strobe safety timeout.
   */
  d_count = (u32)value * 64U / 255U;
  if (d_count < 8U)
    d_count = 8U;
  if (d_count > 64U)
    d_count = 64U;
  d_reg = (~(2U * d_count)) & 0xffffU;

  spin_lock_irqsave(&torch_lock, flags);

  writel_relaxed(RCGR_CFG_150KHZ_XO, gcc_camss_base + GCC_CAMSS_GP1_CFG_RCGR);
  writel_relaxed(RCGR_M_150KHZ, gcc_camss_base + GCC_CAMSS_GP1_M_REG);
  writel_relaxed(RCGR_N_150KHZ, gcc_camss_base + GCC_CAMSS_GP1_N_REG);
  writel_relaxed(d_reg, gcc_camss_base + GCC_CAMSS_GP1_D_REG);
  writel_relaxed(RCGR_CMD_ENABLE_UPDATE, gcc_camss_base + GCC_CAMSS_GP1_CMD_RCGR);
  wmb();

  writel_relaxed(0x1U, gcc_camss_base + GCC_CAMSS_GP1_CBCR_STOCK);
  writel_relaxed(0x1U, gcc_camss_base + GCC_CAMSS_GP1_CBCR_MAIN);
  writel_relaxed(GPIO32_CFG_CCI_TIMER1, tlmm_gpio32_base + GPIO32_CFG_REG);
  wmb();

  current_brightness = value;
  spin_unlock_irqrestore(&torch_lock, flags);
}

static void msm8905_torch_hw_disable(void)
{
  unsigned long flags;

  spin_lock_irqsave(&torch_lock, flags);

  writel_relaxed(GPIO32_CFG_GPIO_OFF, tlmm_gpio32_base + GPIO32_CFG_REG);
  writel_relaxed(0x0U, gcc_camss_base + GCC_CAMSS_GP1_CBCR_STOCK);
  writel_relaxed(0x0U, gcc_camss_base + GCC_CAMSS_GP1_CBCR_MAIN);
  writel_relaxed(0x0U, gcc_camss_base + GCC_CAMSS_GP1_CMD_RCGR);
  wmb();

  current_brightness = LED_OFF;
  spin_unlock_irqrestore(&torch_lock, flags);
}

static void msm8905_torch_brightness_set(struct led_classdev *led_cdev,
                                         enum led_brightness value)
{
  if (value == LED_OFF)
    msm8905_torch_hw_disable();
  else
    msm8905_torch_hw_enable(value);
}

static enum led_brightness msm8905_torch_brightness_get(struct led_classdev *led_cdev)
{
  return current_brightness;
}

static struct led_classdev msm8905_torch_led = {
  .name = "white:torch",
  .max_brightness = LED_FULL,
  .brightness_set = msm8905_torch_brightness_set,
  .brightness_get = msm8905_torch_brightness_get,
  .flags = LED_CORE_SUSPENDRESUME,
};

static int msm8905_pon_reboot_notify(struct notifier_block *nb,
                                     unsigned long action, void *data)
{
  unsigned int ctl1 = 0;
  unsigned int ctl2 = 0;
  unsigned int rst_type;

  msm8905_torch_hw_disable();

  if (!pon_regmap)
    return NOTIFY_DONE;

  if (action == SYS_POWER_OFF || action == SYS_HALT)
    rst_type = PON_POWER_OFF_SHUTDOWN;
  else
    rst_type = PON_POWER_OFF_WARM_RESET;

  /*
   * Match Qualcomm qpnp_pon_system_pwr_off():
   * 1. Disable S2_CNTL_EN (bit 7 of 0x085b)
   * 2. Wait >10 sleep clock cycles (~500 us)
   * 3. Program PS_HOLD_RST_CTL (0x085a) to SHUTDOWN (0x04) or WARM_RESET (0x01)
   * 4. Re-enable S2_CNTL_EN (bit 7 of 0x085b) and wait ~500 us
   */
  if (regmap_read(pon_regmap, QPNP_PON_PS_HOLD_RST_CTL2, &ctl2) == 0)
    regmap_write(pon_regmap, QPNP_PON_PS_HOLD_RST_CTL2, ctl2 & ~QPNP_PON_S2_CNTL_EN);
  else
    regmap_write(pon_regmap, QPNP_PON_PS_HOLD_RST_CTL2, 0x00U);

  udelay(500);

  if (regmap_read(pon_regmap, QPNP_PON_PS_HOLD_RST_CTL, &ctl1) == 0)
    ctl1 = (ctl1 & ~QPNP_PON_RST_TYPE_MASK) | rst_type;
  else
    ctl1 = rst_type;
  regmap_write(pon_regmap, QPNP_PON_PS_HOLD_RST_CTL, ctl1);

  udelay(500);

  regmap_write(pon_regmap, QPNP_PON_PS_HOLD_RST_CTL2,
               (ctl2 & ~QPNP_PON_S2_CNTL_EN) | QPNP_PON_S2_CNTL_EN);
  udelay(500);

  pr_info("leds-msm8905-torch: configured PM8909 PON PS_HOLD_RST_CTL=0x%02x for %s\n",
          ctl1, (rst_type == PON_POWER_OFF_SHUTDOWN) ? "shutdown" : "reboot");
  return NOTIFY_OK;
}

static struct notifier_block msm8905_pon_reboot_nb = {
  .notifier_call = msm8905_pon_reboot_notify,
  .priority = 128,
};

static void msm8905_pon_lookup_regmap(void)
{
  struct device_node *np;
  struct platform_device *pon_pdev;

  np = of_find_compatible_node(NULL, NULL, "qcom,pm8916-pon");
  if (!np)
    return;

  pon_pdev = of_find_device_by_node(np);
  of_node_put(np);
  if (!pon_pdev)
    return;

  if (pon_pdev->dev.parent)
    pon_regmap = dev_get_regmap(pon_pdev->dev.parent, NULL);

  put_device(&pon_pdev->dev);
}

static int __init msm8905_torch_init(void)
{
  int ret;

  if (!of_machine_is_compatible("qcom,msm8905") &&
      !of_machine_is_compatible("qcom,msm8909") &&
      !of_machine_is_compatible("nokia,argon")) {
    return -ENODEV;
  }

  tlmm_gpio32_base = ioremap(MSM8905_TLMM_GPIO32_PHYS, MSM8905_TLMM_GPIO32_SIZE);
  if (!tlmm_gpio32_base)
    return -ENOMEM;

  gcc_camss_base = ioremap(MSM8905_GCC_CAMSS_PHYS, MSM8905_GCC_CAMSS_SIZE);
  if (!gcc_camss_base) {
    iounmap(tlmm_gpio32_base);
    return -ENOMEM;
  }

  msm8905_torch_hw_disable();

  ret = led_classdev_register(NULL, &msm8905_torch_led);
  if (ret) {
    iounmap(gcc_camss_base);
    iounmap(tlmm_gpio32_base);
    return ret;
  }

  msm8905_pon_lookup_regmap();
  register_reboot_notifier(&msm8905_pon_reboot_nb);

  pr_info("leds-msm8905-torch: registered white:torch on GPIO_32 (cci_timer1 150kHz PWM), pon_regmap=%s\n",
          pon_regmap ? "ready" : "none");
  return 0;
}

static void __exit msm8905_torch_exit(void)
{
  unregister_reboot_notifier(&msm8905_pon_reboot_nb);
  led_classdev_unregister(&msm8905_torch_led);
  msm8905_torch_hw_disable();
  iounmap(gcc_camss_base);
  iounmap(tlmm_gpio32_base);
}

module_init(msm8905_torch_init);
module_exit(msm8905_torch_exit);

MODULE_DESCRIPTION("Qualcomm MSM8905 / Nokia 8110 4G SY7807 Torch LED & PM8909 PON Shutdown driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:leds-msm8905-torch");