Re: [PATCH v2 02/11] mfd: wcd934x: add support to wcd9340/wcd9341 codec

From: Lee Jones
Date: Mon Oct 21 2019 - 06:46:19 EST


On Fri, 18 Oct 2019, Srinivas Kandagatla wrote:

> Qualcomm WCD9340/WCD9341 Codec is a standalone Hi-Fi audio codec IC.
>
> This codec has integrated SoundWire controller, pin controller and
> interrupt controller.
>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> ---
> drivers/mfd/Kconfig | 8 +
> drivers/mfd/Makefile | 1 +
> drivers/mfd/wcd934x.c | 330 ++++++++++++++++
> include/linux/mfd/wcd934x/registers.h | 529 ++++++++++++++++++++++++++
> include/linux/mfd/wcd934x/wcd934x.h | 24 ++
> 5 files changed, 892 insertions(+)
> create mode 100644 drivers/mfd/wcd934x.c
> create mode 100644 include/linux/mfd/wcd934x/registers.h
> create mode 100644 include/linux/mfd/wcd934x/wcd934x.h
>
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index ae24d3ea68ea..ab09862b5996 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -1967,6 +1967,14 @@ config MFD_STMFX
> additional drivers must be enabled in order to use the functionality
> of the device.
>
> +config MFD_WCD934X
> + tristate "Support for WCD9340/WCD9341 Codec"
> + depends on SLIMBUS
> + select REGMAP
> + select REGMAP_SLIMBUS
> + select REGMAP_IRQ
> + select MFD_CORE
> +

No help?

> menu "Multimedia Capabilities Port drivers"
> depends on ARCH_SA1100
>
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index c1067ea46204..8059a9c36188 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -58,6 +58,7 @@ endif
> ifeq ($(CONFIG_MFD_CS47L24),y)
> obj-$(CONFIG_MFD_ARIZONA) += cs47l24-tables.o
> endif
> +obj-$(CONFIG_MFD_WCD934X) += wcd934x.o
> obj-$(CONFIG_MFD_WM8400) += wm8400-core.o
> wm831x-objs := wm831x-core.o wm831x-irq.o wm831x-otp.o
> wm831x-objs += wm831x-auxadc.o
> diff --git a/drivers/mfd/wcd934x.c b/drivers/mfd/wcd934x.c
> new file mode 100644
> index 000000000000..bb4d2a6c89bc
> --- /dev/null
> +++ b/drivers/mfd/wcd934x.c
> @@ -0,0 +1,330 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (c) 2019, Linaro Limited
> +
> +#include <linux/clk.h>
> +#include <linux/gpio.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/wcd934x/registers.h>
> +#include <linux/mfd/wcd934x/wcd934x.h>
> +#include <linux/module.h>
> +#include <linux/of_gpio.h>
> +#include <linux/of.h>
> +#include <linux/of_irq.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/slimbus.h>
> +
> +static const struct mfd_cell wcd934x_devices[] = {
> + { /* Audio Codec */

These comments aren't required. The .names are good enough.

> + .name = "wcd934x-codec",
> + }, { /* Pin controller */
> + .name = "wcd934x-pinctrl",
> + .of_compatible = "qcom,wcd9340-pinctrl",
> + }, { /* Soundwire Controller */
> + .name = "wcd934x-soundwire",
> + .of_compatible = "qcom,soundwire-v1.3.0",
> + },
> +};
> +
> +static const struct regmap_irq wcd934x_irqs[] = {
> + /* INTR_REG 0 */

Again, doesn't really add or explain anything additional.

> + [WCD934X_IRQ_SLIMBUS] = {
> + .reg_offset = 0,
> + .mask = BIT(0),
> + .type = {
> + .type_reg_offset = 0,
> + .types_supported = IRQ_TYPE_EDGE_BOTH,
> + .type_reg_mask = BIT(0),
> + .type_level_low_val = BIT(0),
> + .type_level_high_val = BIT(0),
> + .type_falling_val = 0,
> + .type_rising_val = 0,
> + },
> + },
> + [WCD934X_IRQ_SOUNDWIRE] = {
> + .reg_offset = 2,
> + .mask = BIT(4),
> + .type = {
> + .type_reg_offset = 2,
> + .types_supported = IRQ_TYPE_EDGE_BOTH,
> + .type_reg_mask = BIT(4),
> + .type_level_low_val = BIT(4),
> + .type_level_high_val = BIT(4),
> + .type_falling_val = 0,
> + .type_rising_val = 0,
> + },
> + },
> +};
> +
> +static const struct regmap_irq_chip wcd934x_regmap_irq_chip = {
> + .name = "wcd934x_irq",
> + .status_base = WCD934X_INTR_PIN1_STATUS0,
> + .mask_base = WCD934X_INTR_PIN1_MASK0,
> + .ack_base = WCD934X_INTR_PIN1_CLEAR0,
> + .type_base = WCD934X_INTR_LEVEL0,
> + .num_type_reg = 4,
> + .type_in_mask = false,
> + .num_regs = 4,
> + .irqs = wcd934x_irqs,
> + .num_irqs = ARRAY_SIZE(wcd934x_irqs),
> +};
> +
> +static bool wcd934x_is_volatile_register(struct device *dev, unsigned int reg)
> +{
> + switch (reg) {
> + case WCD934X_INTR_PIN1_STATUS0...WCD934X_INTR_PIN2_CLEAR3:
> + case WCD934X_SWR_AHB_BRIDGE_RD_DATA_0:
> + case WCD934X_SWR_AHB_BRIDGE_RD_DATA_1:
> + case WCD934X_SWR_AHB_BRIDGE_RD_DATA_2:
> + case WCD934X_SWR_AHB_BRIDGE_RD_DATA_3:
> + case WCD934X_SWR_AHB_BRIDGE_ACCESS_STATUS:
> + case WCD934X_ANA_MBHC_RESULT_3:
> + case WCD934X_ANA_MBHC_RESULT_2:
> + case WCD934X_ANA_MBHC_RESULT_1:
> + case WCD934X_ANA_MBHC_MECH:
> + case WCD934X_ANA_MBHC_ELECT:
> + case WCD934X_ANA_MBHC_ZDET:
> + case WCD934X_ANA_MICB2:
> + case WCD934X_ANA_RCO:
> + case WCD934X_ANA_BIAS:
> + return true;
> + default:
> + return false;
> + }
> +
> +};
> +
> +static const struct regmap_range_cfg wcd934x_ranges[] = {
> + { .name = "WCD934X",
> + .range_min = 0x0,
> + .range_max = WCD934X_MAX_REGISTER,
> + .selector_reg = WCD934X_SEL_REGISTER,
> + .selector_mask = WCD934X_SEL_MASK,
> + .selector_shift = WCD934X_SEL_SHIFT,
> + .window_start = WCD934X_WINDOW_START,
> + .window_len = WCD934X_WINDOW_LENGTH,
> + },
> +};
> +
> +static struct regmap_config wcd934x_regmap_config = {
> + .reg_bits = 16,
> + .val_bits = 8,
> + .cache_type = REGCACHE_RBTREE,
> + .max_register = 0xffff,
> + .can_multi_write = true,
> + .ranges = wcd934x_ranges,
> + .num_ranges = ARRAY_SIZE(wcd934x_ranges),
> + .volatile_reg = wcd934x_is_volatile_register,
> +};
> +
> +static int wcd934x_parse_resources(struct wcd934x_data *wcd)
> +{
> + struct device *dev = wcd->dev;

Since most things stem from the device, it's more common to pass that
instead. You can then use dev_get_drvdata() to obtain the device
data.

> + struct device_node *np = dev->of_node;
> + int ret;
> +
> + wcd->irq = of_irq_get(wcd->dev->of_node, 0);
> + if (wcd->irq < 0) {
> + if (wcd->irq != -EPROBE_DEFER)
> + dev_err(wcd->dev, "Failed to get IRQ: err = %d\n",
> + wcd->irq);
> + return wcd->irq;
> + }
> +
> + wcd->reset_gpio = of_get_named_gpio(np, "reset-gpios", 0);
> + if (wcd->reset_gpio < 0) {
> + dev_err(dev, "Failed to get reset gpio: err = %d\n",
> + wcd->reset_gpio);
> + return wcd->reset_gpio;
> + }
> +
> + wcd->extclk = devm_clk_get(dev, "extclk");
> + if (IS_ERR(wcd->extclk)) {
> + dev_err(dev, "Failed to get extclk");
> + return PTR_ERR(wcd->extclk);
> + }
> +
> + wcd->supplies[0].supply = "vdd-buck";
> + wcd->supplies[1].supply = "vdd-buck-sido";
> + wcd->supplies[2].supply = "vdd-tx";
> + wcd->supplies[3].supply = "vdd-rx";
> + wcd->supplies[4].supply = "vdd-io";
> +
> + ret = regulator_bulk_get(dev, WCD934X_MAX_SUPPLY, wcd->supplies);
> + if (ret != 0) {
> + dev_err(dev, "Failed to get supplies: err = %d\n", ret);
> + return ret;
> + }

More of a nit-pick really, but I don't see any reason for all of this
not to be in probe.

> + return 0;
> +}
> +
> +static int wcd934x_power_on_reset(struct wcd934x_data *wcd)
> +{
> + int ret;
> +
> + ret = regulator_bulk_enable(WCD934X_MAX_SUPPLY, wcd->supplies);
> + if (ret != 0) {
> + dev_err(wcd->dev, "Failed to get supplies: err = %d\n", ret);
> + return ret;
> + }

By doing regulator_bulk_{get,enable}() in separate functions, you put
an unnecessary burden on 'struct wcd934x_data'. Unless of course
you're using 'supplies' to disable and put as well. Where does that
happen? Surely you should do that in .remove()?

> + /*
> + * For WCD934X, it takes about 600us for the Vout_A and
> + * Vout_D to be ready after BUCK_SIDO is powered up.
> + * SYS_RST_N shouldn't be pulled high during this time
> + */
> + usleep_range(600, 650);
> + gpio_direction_output(wcd->reset_gpio, 0);
> + msleep(20);
> + gpio_set_value(wcd->reset_gpio, 1);
> + msleep(20);
> +
> + return 0;
> +}
> +
> +static int wcd934x_slim_probe(struct slim_device *sdev)

I'd expect to find the .probe() closer to the bottom of the file.

> +{
> + struct device *dev = &sdev->dev;
> + struct wcd934x_data *wcd;

This is actually "ddata". It's more common to do:

struct wcd934x_ddata *ddata;

> + int ret = 0;

Why does this need pre-initialisation?

> + wcd = devm_kzalloc(dev, sizeof(*wcd), GFP_KERNEL);
> + if (!wcd)
> + return -ENOMEM;
> +
> + wcd->dev = dev;

'\n' here.

> + ret = wcd934x_parse_resources(wcd);
> + if (ret) {
> + dev_err(dev, "Error parsing DT: err = %d\n", ret);

You've already printed an error at this point. No need for another.

> + return ret;
> + }
> +
> + ret = wcd934x_power_on_reset(wcd);
> + if (ret) {
> + dev_err(dev, "Error Power resetting device: err = %d\n", ret);

You've already printed an error at this point. No need for another.

> + return ret;
> + }
> +
> + wcd->sdev = sdev;
> + dev_set_drvdata(dev, wcd);

Do this first, then you can use dev_get_drvdata() above.

> + return 0;
> +}
> +
> +static int wcd934x_bring_up(struct wcd934x_data *wcd)
> +{
> + struct regmap *rm = wcd->regmap;

It's much more common to use 'regmap' or 'map'.

> + u16 id_minor, id_major;
> + int ret;
> +
> + ret = regmap_bulk_read(rm, WCD934X_CHIP_TIER_CTRL_CHIP_ID_BYTE0,
> + (u8 *)&id_minor, sizeof(u16));
> + if (ret)
> + return -EINVAL;
> +
> + ret = regmap_bulk_read(rm, WCD934X_CHIP_TIER_CTRL_CHIP_ID_BYTE2,
> + (u8 *)&id_major, sizeof(u16));
> + if (ret)
> + return -EINVAL;
> +
> + dev_info(wcd->dev, "wcd934x chip id major 0x%x, minor 0x%x\n",
> + id_major, id_minor);
> +
> + regmap_write(rm, WCD934X_CODEC_RPM_RST_CTL, 0x01);
> + regmap_write(rm, WCD934X_SIDO_NEW_VOUT_A_STARTUP, 0x19);
> + regmap_write(rm, WCD934X_SIDO_NEW_VOUT_D_STARTUP, 0x15);
> + /* Add 1msec delay for VOUT to settle */
> + usleep_range(1000, 1100);
> + regmap_write(rm, WCD934X_CODEC_RPM_PWR_CDC_DIG_HM_CTL, 0x5);
> + regmap_write(rm, WCD934X_CODEC_RPM_PWR_CDC_DIG_HM_CTL, 0x7);
> + regmap_write(rm, WCD934X_CODEC_RPM_RST_CTL, 0x3);
> + regmap_write(rm, WCD934X_CODEC_RPM_RST_CTL, 0x7);
> + regmap_write(rm, WCD934X_CODEC_RPM_PWR_CDC_DIG_HM_CTL, 0x3);
> +
> + return 0;
> +

Superfluous '\n'.

> +}
> +
> +static int wcd934x_slim_status(struct slim_device *sdev,
> + enum slim_device_status status)
> +{
> + struct device *dev = &sdev->dev;
> + struct wcd934x_data *wcd;
> + int ret;

This is semantically odd! Why are you doing most of the
initialisation and bring-up in 'status' and not 'probe'. Seems
broken to me.

> + wcd = dev_get_drvdata(dev);
> +
> + switch (status) {
> + case SLIM_DEVICE_STATUS_UP:
> + wcd->regmap = regmap_init_slimbus(sdev, &wcd934x_regmap_config);
> + if (IS_ERR(wcd->regmap)) {
> + dev_err(dev, "Error allocating slim regmap\n");
> + return PTR_ERR(wcd->regmap);
> + }
> +
> + ret = wcd934x_bring_up(wcd);
> + if (ret) {
> + dev_err(dev, "Error WCD934X bringup: err = %d\n", ret);

Please use well formed English.

"Failed to bring up WCD934X".

> + return ret;
> + }
> +
> + ret = devm_regmap_add_irq_chip(wcd->dev, wcd->regmap, wcd->irq,
> + IRQF_TRIGGER_HIGH, 0,
> + &wcd934x_regmap_irq_chip,
> + &wcd->irq_data);
> + if (ret) {
> + dev_err(wcd->dev, "Error adding irq_chip: err = %d\n",

"Failed to add IRQ chip".

> + ret);
> + return ret;
> + }
> +
> + ret = mfd_add_devices(wcd->dev, 0, wcd934x_devices,

What do you mean by 0 here?

> + ARRAY_SIZE(wcd934x_devices),
> + NULL, 0, NULL);
> + if (ret) {
> + dev_err(wcd->dev, "Error add mfd devices: err = %d\n",

"Failed to add child devices".

> + ret);
> + return ret;
> + }
> + break;
> + case SLIM_DEVICE_STATUS_DOWN:
> + mfd_remove_devices(wcd->dev);
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static void wcd934x_slim_remove(struct slim_device *sdev)
> +{
> + struct wcd934x_data *wcd = dev_get_drvdata(&sdev->dev);

No more clean-up? Aren't the regulators still enabled?

> + mfd_remove_devices(&sdev->dev);
> + kfree(wcd);
> +}
> +
> +static const struct slim_device_id wcd934x_slim_id[] = {
> + {SLIM_MANF_ID_QCOM, SLIM_PROD_CODE_WCD9340, 0x1, 0x0},

' 's before and after first and last chars please.

> + {}
> +};
> +
> +static struct slim_driver wcd934x_slim_driver = {
> + .driver = {
> + .name = "wcd934x-slim",
> + },
> + .probe = wcd934x_slim_probe,
> + .remove = wcd934x_slim_remove,
> + .device_status = wcd934x_slim_status,
> + .id_table = wcd934x_slim_id,
> +};
> +
> +module_slim_driver(wcd934x_slim_driver);
> +MODULE_DESCRIPTION("WCD934X slim driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("slim:217:250:*");

MODULE_AUTHOR?

[...]

> +#endif
> diff --git a/include/linux/mfd/wcd934x/wcd934x.h b/include/linux/mfd/wcd934x/wcd934x.h
> new file mode 100644
> index 000000000000..d102e211948c
> --- /dev/null
> +++ b/include/linux/mfd/wcd934x/wcd934x.h
> @@ -0,0 +1,24 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +#ifndef __WCD934X_H__
> +#define __WCD934X_H__
> +#include <linux/clk.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/regmap.h>
> +#include <linux/slimbus.h>
> +
> +#define WCD934X_MAX_SUPPLY 5

Kernel doc?

> +struct wcd934x_data {
> + int reset_gpio;
> + int irq;

I'd prefer to see the more complex 'struct's at the top.

> + struct device *dev;
> + struct clk *extclk;
> + struct regmap *regmap;
> + struct slim_device *sdev;

You don't need 'sdev' and 'dev'.

> + struct regmap_irq_chip_data *irq_data;
> + struct regulator_bulk_data supplies[WCD934X_MAX_SUPPLY];
> +};
> +
> +#endif /* __WCD934X_H__ */
> +

--
Lee Jones [æçæ]
Linaro Services Technical Lead
Linaro.org â Open source software for ARM SoCs
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