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[90.5.10.86]) by smtp.gmail.com with ESMTPSA id n11-20020a5d4c4b000000b0031fbbe347ebsm1901426wrt.22.2023.09.21.07.22.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 21 Sep 2023 07:22:47 -0700 (PDT) From: David Lechner To: linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-staging@lists.linux.dev Cc: linux-kernel@vger.kernel.org, Jonathan Cameron , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Michael Hennerich , =?utf-8?q?Nuno_S=C3=A1?= , Axel Haslam , Philip Molloy , David Lechner Subject: [v2 17/19] staging: iio: resolver: ad2s1210: convert resolution to devicetree property Date: Thu, 21 Sep 2023 09:19:45 -0500 Message-Id: <20230921141947.57784-20-dlechner@baylibre.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230921141947.57784-1-dlechner@baylibre.com> References: <20230921141947.57784-1-dlechner@baylibre.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org 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 --- 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 14bec2b20939..71f0913b7e2e 100644 --- a/drivers/staging/iio/resolver/ad2s1210.c +++ b/drivers/staging/iio/resolver/ad2s1210.c @@ -65,6 +65,13 @@ 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; @@ -72,13 +79,12 @@ 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 fclkin; - u8 resolution; + /** The selected resolution */ + enum ad2s1210_resolution resolution; u8 rx[2] __aligned(IIO_DMA_MINALIGN); u8 tx[2]; }; @@ -205,18 +211,6 @@ static int ad2s1210_set_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 excitation_frequency_show(struct device *dev, struct device_attribute *attr, char *buf) @@ -265,50 +259,6 @@ static ssize_t excitation_frequency_store(struct device *dev, return ret; } -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) @@ -556,8 +506,6 @@ static int ad2s1210_write_raw(struct iio_dev *indio_dev, } static IIO_DEVICE_ATTR_RW(excitation_frequency, 0); -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); @@ -604,7 +552,6 @@ static const struct iio_chan_spec ad2s1210_channels[] = { static struct attribute *ad2s1210_attributes[] = { &iio_dev_attr_excitation_frequency.dev_attr.attr, - &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, @@ -626,12 +573,10 @@ 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; data = AD2S1210_DEF_CONTROL & ~AD2S1210_SET_RES; - data |= (st->resolution - 10) >> 1; + data |= st->resolution; + ret = regmap_write(st->regmap, AD2S1210_REG_CONTROL, data); if (ret < 0) goto error_ret; @@ -670,6 +615,26 @@ 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; @@ -691,6 +656,9 @@ 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); @@ -708,16 +676,31 @@ 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; } @@ -782,7 +765,10 @@ 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)