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author | John Klug <john.klug@multitech.com> | 2020-02-25 17:55:49 -0600 |
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committer | John Klug <john.klug@multitech.com> | 2020-10-16 10:21:24 -0500 |
commit | d33777bacc8abe8530016ad0e4fe3a604c0a5a48 (patch) | |
tree | 71ef221c0b44e62d1ff42dbd0ca02ac7c9a7e5cb /io-module/adc.c | |
parent | aa3be1b385cc26566745207d7862fa9067dcdf3c (diff) | |
download | mts-io-d33777bacc8abe8530016ad0e4fe3a604c0a5a48.tar.gz mts-io-d33777bacc8abe8530016ad0e4fe3a604c0a5a48.tar.bz2 mts-io-d33777bacc8abe8530016ad0e4fe3a604c0a5a48.zip |
mts-io based on thud/4.19 kernel for mt100eocg
Diffstat (limited to 'io-module/adc.c')
-rw-r--r-- | io-module/adc.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/io-module/adc.c b/io-module/adc.c new file mode 100644 index 0000000..3d5f3d0 --- /dev/null +++ b/io-module/adc.c @@ -0,0 +1,126 @@ +#define AT91SAM9X5_BASE_ADC 0xf804c000 +#define AT91SAM9260_BASE_ADC 0xfffe0000 + +#define ADC_SHTIME_DEFAULT 0x05 +#define ADC_STARTUP_DEFAULT 0x04 +#define ADC_PRESCALE_DEFAULT 0x3F +#define ADC_MODE_DEFAULT \ + ((ADC_SHTIME_DEFAULT & 0x0F) << 24) | \ + ((ADC_STARTUP_DEFAULT & 0x1F) << 16) | \ + ((ADC_PRESCALE_DEFAULT & 0x3F) << 8) + +#define ADC_CR_OFFSET 0x00 +#define ADC_MR_OFFSET 0x04 +#define ADC_CHER_OFFSET 0x10 +#define ADC_CHDR_OFFSET 0x14 +#define ADC_CHSR_OFFSET 0x18 +#define ADC_SR_OFFSET 0x1C +#define ADC_LDCR_OFFSET 0x20 +#define ADC_IER_OFFSET 0x14 +#define ADC_IDR_OFFSET 0x28 +#define ADC_IMR_OFFSET 0x2C +#define ADC_CDR0_OFFSET 0x30 +#define ADC_CDR1_OFFSET 0x34 +#define ADC_CDR2_OFFSET 0x38 +#define ADC_CDR3_OFFSET 0x3C + +void __iomem *adc_base; +struct clk *adc_clk; + +#define ADC_CONVERT_RESET(base) writel(0x01, (base) + ADC_CR_OFFSET) +#define ADC_CONVERT_START(base) writel(0x02, (base) + ADC_CR_OFFSET) + +static ssize_t mts_attr_show_adc(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + int offset; + u32 value; + u32 chan_mask; + + if (!DEVICE_CAPA(id_eeprom.capa, CAPA_ADC)) { + log_debug("ADC not available"); + return -ENODEV; + } + + if (!strcmp(attr->attr.name, "adc0")) { + offset = ADC_CDR0_OFFSET; + chan_mask = 0x01; + } else if (!strcmp(attr->attr.name, "adc1")) { + offset = ADC_CDR1_OFFSET; + chan_mask = 0x02; + } else if (!strcmp(attr->attr.name, "adc2")) { + offset = ADC_CDR2_OFFSET; + chan_mask = 0x04; + } else if (!strcmp(attr->attr.name, "adc3")) { + offset = ADC_CDR3_OFFSET; + chan_mask = 0x08; + } else { + log_notice("adc attr does not exist"); + return -ENOENT; + } + + mutex_lock(&mts_io_mutex); + + // disable all channels and enable the one we want + writel(0x0F, adc_base + ADC_CHDR_OFFSET); + writel(chan_mask, adc_base + ADC_CHER_OFFSET); + + ADC_CONVERT_START(adc_base); + + // wait for conversion to complete (EOC bit set) + value = 0; + while (value != chan_mask) { + value = readl(adc_base + ADC_SR_OFFSET) & chan_mask; + log_debug("ADC_SR EOC [%X]", value); + } + + // read result + value = readl(adc_base + offset); + + mutex_unlock(&mts_io_mutex); + + return sprintf(buf, "%lu\n", (unsigned long) value); +} + +static DEVICE_ATTR_RO_MTS(dev_attr_adc0, "adc0", mts_attr_show_adc); +static DEVICE_ATTR_RO_MTS(dev_attr_adc1, "adc1", mts_attr_show_adc); +static DEVICE_ATTR_RO_MTS(dev_attr_adc2, "adc2", mts_attr_show_adc); +static DEVICE_ATTR_RO_MTS(dev_attr_adc3, "adc3", mts_attr_show_adc); + +static int mts_io_board_adc_probe(struct platform_device *pdev) +{ + int err; + adc_clk = clk_get(&pdev->dev, "adc_clk"); + if (adc_clk) { + err = clk_prepare_enable(adc_clk); + if (err) { + log_error("clock failed to prepare+enable: %d\n", err); + return err; + } + #ifdef CONFIG_SOC_AT91SAM9X5 + adc_base = ioremap(AT91SAM9X5_BASE_ADC, SZ_16K); + #else + adc_base = ioremap(AT91SAM9260_BASE_ADC, SZ_16K); + #endif + if (!adc_base) { + log_error("ioremap failed.\n"); + return -ENOMEM; + } + ADC_CONVERT_RESET(adc_base); + writel(ADC_MODE_DEFAULT, adc_base + ADC_MR_OFFSET); + writel(0x000F0F0F, adc_base + ADC_IDR_OFFSET); + writel(0x0F, adc_base + ADC_CHDR_OFFSET); + } + return 0; +} + +static int mts_io_board_adc_remove(struct platform_device *pdev) +{ + if (adc_clk) { + int ret; + clk_disable_unprepare(adc_clk); + } + return 0; +} + |