Re: [PATCH v2 02/10] mfd: wcd9335: add support to wcd9335 core

Lee Jones
2018-08-02T08:33:59Z

On Fri, 27 Jul 2018, Srinivas Kandagatla wrote:

> Qualcomm WCD9335 Codec is a standalone Hi-Fi audio codec IC,
> It has mulitple blocks like Soundwire controller, codec,
> Codec processing engine, ClassH controller, interrupt mux.
> It supports both I2S/I2C and SLIMbus audio interfaces.
>
> This patch adds support to SLIMbus audio interface.
>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> ---
> drivers/mfd/Kconfig | 18 ++
> drivers/mfd/Makefile | 4 +
> drivers/mfd/wcd9335-core.c | 268 ++++++++++++++++
> include/linux/mfd/wcd9335/registers.h | 580 ++++++++++++++++++++++++++++++++++
> include/linux/mfd/wcd9335/wcd9335.h | 42 +++
> 5 files changed, 912 insertions(+)
> create mode 100644 drivers/mfd/wcd9335-core.c
> create mode 100644 include/linux/mfd/wcd9335/registers.h
> create mode 100644 include/linux/mfd/wcd9335/wcd9335.h
>
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index f3fa516011ec..6e5b5f3cfe20 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -1807,6 +1807,24 @@ config MFD_WM97xx
> support for the WM97xx, in order to use the actual functionaltiy of
> the device other drivers must be enabled.
>
> +config MFD_WCD9335
> + tristate
> + select MFD_CORE
> + select REGMAP
> + select REGMAP_IRQ
> +
> +config MFD_WCD9335_SLIM
> + tristate "Qualcomm WCD9335 with SLIMbus"
> + select MFD_WCD9335
> + select REGMAP_SLIMBUS
> + depends on SLIMBUS
> + help
> + The WCD9335 is a standalone Hi-Fi audio codec IC, supports

s/codec/CODEC/

> + Qualcomm Technologies, Inc. (QTI) multimedia solutions, including
> + the MSM8996, MSM8976, and MSM8956 chipsets. It has inbuild

s/inbuild/in-built/

> + Soundwire controller, interrupt mux. It supports both I2S/I2C and
> + SLIMbus audio interfaces. This option selects SLIMbus audio interface.

The help should be indented.

> config MFD_STW481X
> tristate "Support for ST Microelectronics STw481x"
> depends on I2C && (ARCH_NOMADIK || COMPILE_TEST)
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 2852a6042ecf..a4697370640b 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -56,6 +56,10 @@ endif
> ifeq ($(CONFIG_MFD_CS47L24),y)
> obj-$(CONFIG_MFD_ARIZONA) += cs47l24-tables.o
> endif
> +
> +obj-$(CONFIG_MFD_WCD9335) += wcd9335.o
> +wcd9335-objs := wcd9335-core.o
> +
> obj-$(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/wcd9335-core.c b/drivers/mfd/wcd9335-core.c
> new file mode 100644
> index 000000000000..8f746901f4e9
> --- /dev/null
> +++ b/drivers/mfd/wcd9335-core.c
> @@ -0,0 +1,268 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (c) 2018, Linaro Limited
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/slimbus.h>
> +#include <linux/regmap.h>
> +#include <linux/of.h>
> +#include <linux/of_gpio.h>
> +#include <linux/clk.h>
> +#include <linux/gpio.h>
> +#include <linux/mfd/core.h>
> +#include <linux/platform_device.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/mfd/wcd9335/wcd9335.h>
> +#include <linux/mfd/wcd9335/registers.h>

Alphabetical.

> +static const struct regmap_range_cfg wcd9335_ranges[] = {
> + { .name = "WCD9335",

What is that? New line please.

> + .range_min = 0x0,
> + .range_max = WCD9335_MAX_REGISTER,
> + .selector_reg = WCD9335_REG(0x0, 0),
> + .selector_mask = 0xff,
> + .selector_shift = 0,
> + .window_start = 0x0,
> + .window_len = 0x1000,
> + },
> +};
> +
> +static struct regmap_config wcd9335_regmap_config = {
> + .reg_bits = 16,
> + .val_bits = 8,
> + .cache_type = REGCACHE_RBTREE,
> + .max_register = WCD9335_MAX_REGISTER,
> + .can_multi_write = true,
> + .ranges = wcd9335_ranges,
> + .num_ranges = ARRAY_SIZE(wcd9335_ranges),
> +};
> +
> +static const struct regmap_range_cfg wcd9335_ifd_ranges[] = {
> + { .name = "WCD9335-IFD",

As above.

> + .range_min = 0x0,
> + .range_max = WCD9335_REG(0, 0x7ff),
> + .selector_reg = WCD9335_REG(0, 0x0),
> + .selector_mask = 0xff,
> + .selector_shift = 0,
> + .window_start = 0x0,
> + .window_len = 0x1000,
> + },
> +};
> +
> +static struct regmap_config wcd9335_ifd_regmap_config = {
> + .reg_bits = 16,
> + .val_bits = 8,
> + .can_multi_write = true,
> + .max_register = WCD9335_REG(0, 0x7FF),
> + .ranges = wcd9335_ifd_ranges,
> + .num_ranges = ARRAY_SIZE(wcd9335_ifd_ranges),
> +};
> +
> +static int wcd9335_parse_dt(struct wcd9335 *wcd)
> +{
> + struct device *dev = wcd->dev;
> + struct device_node *np = dev->of_node;
> + int ret;
> +
> + wcd->reset_gpio = of_get_named_gpio(np, "reset-gpio", 0);
> + if (wcd->reset_gpio < 0) {
> + dev_err(dev, "Reset gpio missing in DT\n");

s/gpio/GPIO/

s/missing in DT/missing from DT/

> + return wcd->reset_gpio;
> + }
> +
> + wcd->mclk = devm_clk_get(dev, "mclk");
> + if (IS_ERR(wcd->mclk)) {
> + dev_err(dev, "mclk not found\n");
> + return PTR_ERR(wcd->mclk);
> + }
> +
> + wcd->native_clk = devm_clk_get(dev, "slimbus");
> + if (IS_ERR(wcd->native_clk)) {
> + dev_err(dev, "slimbus clk not found\n");

Any reason for abbreviating 'clock' in the error message?

> + return PTR_ERR(wcd->native_clk);
> + }
> +
> + 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, WCD9335_MAX_SUPPLY, wcd->supplies);
> + if (ret != 0) {

"if (ret)"

Same for all. I won't comment on the others.

> + dev_err(dev, "Failed to get supplies: err = %d\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int wcd9335_power_on_reset(struct wcd9335 *wcd)
> +{
> + struct device *dev = wcd->dev;
> + int ret;
> +
> + ret = regulator_bulk_enable(WCD9335_MAX_SUPPLY, wcd->supplies);
> + if (ret != 0) {
> + dev_err(dev, "Failed to get supplies: err = %d\n", ret);
> + return ret;
> + }
> +
> + /*
> + * For WCD9335, 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);

What's this for? Why can't you just:

gpio_direction_output(wcd->reset_gpio, 1);

... and drop the next 2 lines?

> + gpio_set_value(wcd->reset_gpio, 1);
> + msleep(20);
> +
> + return 0;
> +}
> +
> +static int wcd9335_bring_up(struct wcd9335 *wcd)
> +{
> + struct regmap *rm = wcd->regmap;
> + int val, byte0;
> + int ret = 0;
> +
> + regmap_read(rm, WCD9335_CHIP_TIER_CTRL_EFUSE_VAL_OUT0, &val);
> + regmap_read(rm, WCD9335_CHIP_TIER_CTRL_CHIP_ID_BYTE0, &byte0);
> +
> + if ((val < 0) || (byte0 < 0)) {
> + dev_err(wcd->dev, "wcd9335 codec version detection fail!\n");

s/wcd9335 codec/WCD9335 CODEC/ ?

> + return -EINVAL;
> + }
> +
> + if (byte0 == 0x1) {
> + dev_info(wcd->dev, "wcd9335 codec version is v2.0\n");
> + wcd->version = WCD9335_VERSION_2_0;
> + regmap_write(rm, WCD9335_CODEC_RPM_RST_CTL, 0x01);
> + regmap_write(rm, WCD9335_SIDO_SIDO_TEST_2, 0x00);
> + regmap_write(rm, WCD9335_SIDO_SIDO_CCL_8, 0x6F);
> + regmap_write(rm, WCD9335_BIAS_VBG_FINE_ADJ, 0x65);
> + regmap_write(rm, WCD9335_CODEC_RPM_PWR_CDC_DIG_HM_CTL, 0x5);
> + regmap_write(rm, WCD9335_CODEC_RPM_PWR_CDC_DIG_HM_CTL, 0x7);
> + regmap_write(rm, WCD9335_CODEC_RPM_PWR_CDC_DIG_HM_CTL, 0x3);
> + regmap_write(rm, WCD9335_CODEC_RPM_RST_CTL, 0x3);
> + } else {
> + dev_err(wcd->dev, "wcd9335 codec version not supported\n");

As above.

> + ret = -EINVAL;

Why not just

return -EINVAL;

Then you can just return 0 and avoid pre-initialising ret.

> + }
> +
> + return ret;
> +}
> +
> +static int wcd9335_slim_probe(struct slim_device *slim)
> +{
> + struct device *dev = &slim->dev;
> + struct wcd9335 *wcd;
> + int ret = 0;

Why pre-initialise?

> + /* Interface device */
> + if (slim->e_addr.dev_index == 0)

Is 0 the parent? I think 0 needs defining for clarity.

> + return 0;
> +
> + wcd = devm_kzalloc(dev, sizeof(*wcd), GFP_KERNEL);
> + if (!wcd)
> + return -ENOMEM;
> +
> + wcd->dev = dev;

'\n' here.

> + ret = wcd9335_parse_dt(wcd);
> + if (ret) {
> + dev_err(dev, "Error parsing DT (%d)\n", ret);

This format changes from message to message.

Please pick one and stick with it.

I personally like: "<MESSAGE>: %d", ret

> + return ret;
> + }
> +
> + ret = wcd9335_power_on_reset(wcd);
> + if (ret) {
> + dev_err(dev, "Error Powering\n");

I think this is superflouous since you already printed a message.

> + return ret;
> + }
> +
> + wcd->regmap = regmap_init_slimbus(slim, &wcd9335_regmap_config);
> + if (IS_ERR(wcd->regmap)) {
> + ret = PTR_ERR(wcd->regmap);
> + dev_err(dev, "Failed to allocate register map:%d\n", ret);

A different format again. Ensure there is a ' ' after the ':'.

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

Probably nicer to do this at the very end - after a '\n'.

> + wcd->slim = slim;
> + wcd->intf_type = WCD9335_INTERFACE_TYPE_SLIMBUS;
> +
> + return 0;
> +}
> +
> +static const struct mfd_cell wcd9335_devices[] = {
> + {
> + .name = "wcd9335-codec",
> + },
> +};

When are you going to add the other devices?

By the way, one line entries should be placed on one line.

> + { .name = "wcd9335-codec" },

> +static int wcd9335_slim_status(struct slim_device *sdev,
> + enum slim_device_status s)

's' is not a good variable name. Suggest 'status'.

> +{
> + struct device_node *ifd_np;

What's 'ifd'?

> + struct wcd9335 *wcd;
> + struct device *dev;
> + int ret;
> +
> + /* Interface device */

As previously suggested just define the device ID and drop the
comment.

> + if (sdev->e_addr.dev_index == 0)
> + return 0;
> +
> + wcd = dev_get_drvdata(&sdev->dev);
> + dev = wcd->dev;

Odd. You do to the effort of assigning this and use 'wcd->dev' at
most call sites anyway. I'd drop 'dev' and just use it from 'wcd'
everywhere.

> + ifd_np = of_parse_phandle(wcd->dev->of_node, "qcom,ifd", 0);
> + if (!ifd_np) {
> + dev_err(wcd->dev, "No Interface device found\n");
> + return -EINVAL;
> + }
> +
> + wcd->slim_ifd = of_slim_get_device(sdev->ctrl, ifd_np);
> + if (!wcd->slim_ifd) {
> + dev_err(wcd->dev, "Unable to get SLIM Interface device\n");
> + return -EINVAL;
> + }
> +
> + wcd->ifd_regmap = regmap_init_slimbus(wcd->slim_ifd,
> + &wcd9335_ifd_regmap_config);
> + if (IS_ERR(wcd->ifd_regmap)) {
> + dev_err(dev, "Failed to allocate register map\n");
> + return PTR_ERR(wcd->ifd_regmap);
> + }
> +
> + ret = wcd9335_bring_up(wcd);
> + if (ret) {
> + dev_err(dev, "Failed to bringup WCD9335\n");
> + return ret;
> + }
> +
> + wcd->slim_ifd = wcd->slim_ifd;

Am I missing something?

> + return mfd_add_devices(wcd->dev, 0, wcd9335_devices,
> + ARRAY_SIZE(wcd9335_devices), NULL, 0, NULL);

No error message if it were to fail?

> +}
> +
> +static const struct slim_device_id wcd9335_slim_id[] = {
> + {0x217, 0x1a0, 0x1, 0x0},

Well that's just horrific. Can't these be defined?

> + {}
> +};
> +
> +static struct slim_driver wcd9335_slim_driver = {
> + .driver = {
> + .name = "wcd9335-slim",
> + },
> + .probe = wcd9335_slim_probe,
> + .device_status = wcd9335_slim_status,
> + .id_table = wcd9335_slim_id,
> +};
> +
> +module_slim_driver(wcd9335_slim_driver);
> +MODULE_DESCRIPTION("WCD9335 slim driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/mfd/wcd9335/registers.h b/include/linux/mfd/wcd9335/registers.h

--
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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