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[98.183.112.25]) by smtp.gmail.com with ESMTPSA id f128-20020a4a5886000000b0057bb326cad4sm2272915oob.33.2023.09.29.10.26.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 29 Sep 2023 10:26:02 -0700 (PDT) From: David Lechner To: linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-staging@lists.linux.dev Cc: David Lechner , Jonathan Cameron , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Michael Hennerich , =?utf-8?q?Nuno_S=C3=A1?= , Axel Haslam , Philip Molloy , linux-kernel@vger.kernel.org, David Lechner Subject: [PATCH v3 18/27] staging: iio: resolver: ad2s1210: convert resolution to devicetree property Date: Fri, 29 Sep 2023 12:23:23 -0500 Message-ID: <20230929-ad2s1210-mainline-v3-18-fa4364281745@baylibre.com> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230929-ad2s1210-mainline-v3-0-fa4364281745@baylibre.com> References: <20230929-ad2s1210-mainline-v3-0-fa4364281745@baylibre.com> MIME-Version: 1.0 X-Mailer: b4 0.12.3 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org From: David Lechner From: David Lechner Selecting the resolution was implemented as the `bits` sysfs attribute. However, the selection of the resolution depends on how the hardware is wired and the specific application, so this is rather a job for devicetree to describe. A new devicetree property `adi,resolution` to specify the resolution required for each chip is added and the `bits` sysfs attribute is removed. Since the resolution is now supplied by a devicetree property, the resolution-gpios are now optional and we can allow for the case where the resolution pins on the AD2S1210 are hard-wired instead of requiring them to be connected to gpios. Signed-off-by: David Lechner --- v3 changes: * Fixed multiline comment style. drivers/staging/iio/resolver/ad2s1210.c | 136 ++++++++++++++------------------ 1 file changed, 61 insertions(+), 75 deletions(-) diff --git a/drivers/staging/iio/resolver/ad2s1210.c b/drivers/staging/iio/resolver/ad2s1210.c index 6accb9e3db46..a0a426d0af19 100644 --- a/drivers/staging/iio/resolver/ad2s1210.c +++ b/drivers/staging/iio/resolver/ad2s1210.c @@ -63,6 +63,13 @@ enum ad2s1210_mode { MOD_CONFIG = 0b11, }; +enum ad2s1210_resolution { + AD2S1210_RES_10 = 0b00, + AD2S1210_RES_12 = 0b01, + AD2S1210_RES_14 = 0b10, + AD2S1210_RES_16 = 0b11, +}; + struct ad2s1210_state { struct mutex lock; struct spi_device *sdev; @@ -70,13 +77,12 @@ struct ad2s1210_state { struct gpio_desc *sample_gpio; /** GPIO pins connected to A0 and A1 lines. */ struct gpio_descs *mode_gpios; - /** GPIO pins connected to RES0 and RES1 lines. */ - struct gpio_descs *resolution_gpios; /** Used to access config registers. */ struct regmap *regmap; /** The external oscillator frequency in Hz. */ unsigned long clkin_hz; - u8 resolution; + /** The selected resolution */ + enum ad2s1210_resolution resolution; /** For reading raw sample value via SPI. */ __be16 sample __aligned(IIO_DMA_MINALIGN); /** SPI transmit buffer. */ @@ -212,62 +218,6 @@ static int ad2s1210_reinit_excitation_frequency(struct ad2s1210_state *st, return regmap_write(st->regmap, AD2S1210_REG_SOFT_RESET, 0); } -static int ad2s1210_set_resolution_gpios(struct ad2s1210_state *st, - u8 resolution) -{ - struct gpio_descs *gpios = st->resolution_gpios; - DECLARE_BITMAP(bitmap, 2); - - bitmap[0] = (resolution - 10) >> 1; - - return gpiod_set_array_value(gpios->ndescs, gpios->desc, gpios->info, - bitmap); -} - -static ssize_t ad2s1210_show_resolution(struct device *dev, - struct device_attribute *attr, - char *buf) -{ - struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev)); - - return sprintf(buf, "%d\n", st->resolution); -} - -static ssize_t ad2s1210_store_resolution(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t len) -{ - struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev)); - unsigned char data; - unsigned char udata; - int ret; - - ret = kstrtou8(buf, 10, &udata); - if (ret || udata < 10 || udata > 16) { - dev_err(dev, "ad2s1210: resolution out of range\n"); - return -EINVAL; - } - - data = (udata - 10) >> 1; - - mutex_lock(&st->lock); - ret = regmap_update_bits(st->regmap, AD2S1210_REG_CONTROL, - AD2S1210_SET_RES, data); - if (ret < 0) - goto error_ret; - - ret = ad2s1210_set_resolution_gpios(st, udata); - if (ret < 0) - goto error_ret; - - st->resolution = udata; - ret = len; - -error_ret: - mutex_unlock(&st->lock); - return ret; -} - /* read the fault register since last sample */ static ssize_t ad2s1210_show_fault(struct device *dev, struct device_attribute *attr, char *buf) @@ -572,8 +522,6 @@ static int ad2s1210_write_raw(struct iio_dev *indio_dev, } } -static IIO_DEVICE_ATTR(bits, 0644, - ad2s1210_show_resolution, ad2s1210_store_resolution, 0); static IIO_DEVICE_ATTR(fault, 0644, ad2s1210_show_fault, ad2s1210_clear_fault, 0); @@ -628,7 +576,6 @@ static const struct iio_chan_spec ad2s1210_channels[] = { }; static struct attribute *ad2s1210_attributes[] = { - &iio_dev_attr_bits.dev_attr.attr, &iio_dev_attr_fault.dev_attr.attr, &iio_dev_attr_los_thrd.dev_attr.attr, &iio_dev_attr_dos_ovr_thrd.dev_attr.attr, @@ -650,15 +597,12 @@ static int ad2s1210_initial(struct ad2s1210_state *st) int ret; mutex_lock(&st->lock); - ret = ad2s1210_set_resolution_gpios(st, st->resolution); - if (ret < 0) - return ret; /* Use default config register value plus resolution from devicetree. */ data = FIELD_PREP(AD2S1210_PHASE_LOCK_RANGE_44, 1); data |= FIELD_PREP(AD2S1210_ENABLE_HYSTERESIS, 1); data |= FIELD_PREP(AD2S1210_SET_ENRES, 0x3); - data |= FIELD_PREP(AD2S1210_SET_RES, (st->resolution - 10) >> 1); + data |= FIELD_PREP(AD2S1210_SET_RES, st->resolution); ret = regmap_write(st->regmap, AD2S1210_REG_CONTROL, data); if (ret < 0) @@ -698,6 +642,26 @@ static const struct iio_info ad2s1210_info = { .debugfs_reg_access = &ad2s1210_debugfs_reg_access, }; +static int ad2s1210_setup_properties(struct ad2s1210_state *st) +{ + struct device *dev = &st->sdev->dev; + u32 val; + int ret; + + ret = device_property_read_u32(dev, "assigned-resolution-bits", &val); + if (ret < 0) + return dev_err_probe(dev, ret, + "failed to read assigned-resolution-bits property\n"); + + if (val < 10 || val > 16) + return dev_err_probe(dev, -EINVAL, + "resolution out of range: %u\n", val); + + st->resolution = (val - 10) >> 1; + + return 0; +} + static int ad2s1210_setup_clocks(struct ad2s1210_state *st) { struct device *dev = &st->sdev->dev; @@ -719,6 +683,9 @@ static int ad2s1210_setup_clocks(struct ad2s1210_state *st) static int ad2s1210_setup_gpios(struct ad2s1210_state *st) { struct device *dev = &st->sdev->dev; + struct gpio_descs *resolution_gpios; + DECLARE_BITMAP(bitmap, 2); + int ret; /* should not be sampling on startup */ st->sample_gpio = devm_gpiod_get(dev, "sample", GPIOD_OUT_LOW); @@ -736,16 +703,32 @@ static int ad2s1210_setup_gpios(struct ad2s1210_state *st) return dev_err_probe(dev, -EINVAL, "requires exactly 2 mode-gpios\n"); - /* both pins high means that we start with 16-bit resolution */ - st->resolution_gpios = devm_gpiod_get_array(dev, "resolution", - GPIOD_OUT_HIGH); - if (IS_ERR(st->resolution_gpios)) - return dev_err_probe(dev, PTR_ERR(st->resolution_gpios), + /* + * If resolution gpios are provided, they get set to the required + * resolution, otherwise it is assumed the RES0 and RES1 pins are + * hard-wired to match the resolution indicated in the devicetree. + */ + resolution_gpios = devm_gpiod_get_array_optional(dev, "resolution", + GPIOD_ASIS); + if (IS_ERR(resolution_gpios)) + return dev_err_probe(dev, PTR_ERR(resolution_gpios), "failed to request resolution GPIOs\n"); - if (st->resolution_gpios->ndescs != 2) - return dev_err_probe(dev, -EINVAL, - "requires exactly 2 resolution-gpios\n"); + if (resolution_gpios) { + if (resolution_gpios->ndescs != 2) + return dev_err_probe(dev, -EINVAL, + "requires exactly 2 resolution-gpios\n"); + + bitmap[0] = st->resolution; + + ret = gpiod_set_array_value(resolution_gpios->ndescs, + resolution_gpios->desc, + resolution_gpios->info, + bitmap); + if (ret < 0) + return dev_err_probe(dev, ret, + "failed to set resolution gpios\n"); + } return 0; } @@ -809,7 +792,10 @@ static int ad2s1210_probe(struct spi_device *spi) mutex_init(&st->lock); st->sdev = spi; - st->resolution = 12; + + ret = ad2s1210_setup_properties(st); + if (ret < 0) + return ret; ret = ad2s1210_setup_clocks(st); if (ret < 0)