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authorLinus Torvalds <torvalds@linux-foundation.org>2017-07-04 05:57:30 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-07-04 05:57:30 +0300
commitcbcd4f08aa637b74f575268770da86a00fabde6d (patch)
tree449b5da5a05a8539b75640bcc4661147d840e053 /drivers/iio/adc/stm32-adc-core.c
parent362f6729cbb1d6bbab59e069f19441b0622ff7ec (diff)
parent9b326dfce12afb429915c63f5a3df4afa4bea957 (diff)
downloadlinux-cbcd4f08aa637b74f575268770da86a00fabde6d.tar.xz
Merge tag 'staging-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging/IIO updates from Greg KH: "Here's the large set of staging and iio driver patches for 4.13-rc1. After over 500 patches, we removed about 200 more lines of code than we added, not great, but we added some new IIO drivers for unsupported hardware, so it's an overall win. Also here are lots of small fixes, and some tty core api additions (with the tty maintainer's ack) for the speakup drivers, those are finally getting some much needed cleanups and are looking much better now than before. Full details in the shortlog. All of these have been in linux-next for a while with no reported issues" * tag 'staging-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (529 commits) staging: lustre: replace kmalloc with kmalloc_array Staging: ion: fix code style warning from NULL comparisons staging: fsl-mc: make dprc.h header private staging: fsl-mc: move mc-cmd.h contents in the public header staging: fsl-mc: move mc-sys.h contents in the public header staging: fsl-mc: fix a few implicit includes staging: fsl-mc: remove dpmng API files staging: fsl-mc: move rest of mc-bus.h to private header staging: fsl-mc: move couple of definitions to public header staging: fsl-mc: move irq domain creation prototype to public header staging: fsl-mc: turn several exported functions static staging: fsl-mc: delete prototype of unimplemented function staging: fsl-mc: delete duplicated function prototypes staging: fsl-mc: decouple the mc-bus public headers from dprc.h staging: fsl-mc: drop useless #includes staging: fsl-mc: be consistent when checking strcmp() return staging: fsl-mc: move comparison before strcmp() call staging: speakup: make function ser_to_dev static staging: ks7010: fix spelling mistake: "errror" -> "error" staging: rtl8192e: fix spelling mistake: "respose" -> "response" ...
Diffstat (limited to 'drivers/iio/adc/stm32-adc-core.c')
-rw-r--r--drivers/iio/adc/stm32-adc-core.c269
1 files changed, 248 insertions, 21 deletions
diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-core.c
index 22b7c9321e78..e09233b03c05 100644
--- a/drivers/iio/adc/stm32-adc-core.c
+++ b/drivers/iio/adc/stm32-adc-core.c
@@ -49,19 +49,66 @@
/* STM32 F4 maximum analog clock rate (from datasheet) */
#define STM32F4_ADC_MAX_CLK_RATE 36000000
+/* STM32H7 - common registers for all ADC instances */
+#define STM32H7_ADC_CSR (STM32_ADCX_COMN_OFFSET + 0x00)
+#define STM32H7_ADC_CCR (STM32_ADCX_COMN_OFFSET + 0x08)
+
+/* STM32H7_ADC_CSR - bit fields */
+#define STM32H7_EOC_SLV BIT(18)
+#define STM32H7_EOC_MST BIT(2)
+
+/* STM32H7_ADC_CCR - bit fields */
+#define STM32H7_PRESC_SHIFT 18
+#define STM32H7_PRESC_MASK GENMASK(21, 18)
+#define STM32H7_CKMODE_SHIFT 16
+#define STM32H7_CKMODE_MASK GENMASK(17, 16)
+
+/* STM32 H7 maximum analog clock rate (from datasheet) */
+#define STM32H7_ADC_MAX_CLK_RATE 72000000
+
+/**
+ * stm32_adc_common_regs - stm32 common registers, compatible dependent data
+ * @csr: common status register offset
+ * @eoc1: adc1 end of conversion flag in @csr
+ * @eoc2: adc2 end of conversion flag in @csr
+ * @eoc3: adc3 end of conversion flag in @csr
+ */
+struct stm32_adc_common_regs {
+ u32 csr;
+ u32 eoc1_msk;
+ u32 eoc2_msk;
+ u32 eoc3_msk;
+};
+
+struct stm32_adc_priv;
+
+/**
+ * stm32_adc_priv_cfg - stm32 core compatible configuration data
+ * @regs: common registers for all instances
+ * @clk_sel: clock selection routine
+ */
+struct stm32_adc_priv_cfg {
+ const struct stm32_adc_common_regs *regs;
+ int (*clk_sel)(struct platform_device *, struct stm32_adc_priv *);
+};
+
/**
* struct stm32_adc_priv - stm32 ADC core private data
* @irq: irq for ADC block
* @domain: irq domain reference
* @aclk: clock reference for the analog circuitry
+ * @bclk: bus clock common for all ADCs, depends on part used
* @vref: regulator reference
+ * @cfg: compatible configuration data
* @common: common data for all ADC instances
*/
struct stm32_adc_priv {
int irq;
struct irq_domain *domain;
struct clk *aclk;
+ struct clk *bclk;
struct regulator *vref;
+ const struct stm32_adc_priv_cfg *cfg;
struct stm32_adc_common common;
};
@@ -85,14 +132,23 @@ static int stm32f4_adc_clk_sel(struct platform_device *pdev,
u32 val;
int i;
+ /* stm32f4 has one clk input for analog (mandatory), enforce it here */
+ if (!priv->aclk) {
+ dev_err(&pdev->dev, "No 'adc' clock found\n");
+ return -ENOENT;
+ }
+
rate = clk_get_rate(priv->aclk);
for (i = 0; i < ARRAY_SIZE(stm32f4_pclk_div); i++) {
if ((rate / stm32f4_pclk_div[i]) <= STM32F4_ADC_MAX_CLK_RATE)
break;
}
- if (i >= ARRAY_SIZE(stm32f4_pclk_div))
+ if (i >= ARRAY_SIZE(stm32f4_pclk_div)) {
+ dev_err(&pdev->dev, "adc clk selection failed\n");
return -EINVAL;
+ }
+ priv->common.rate = rate;
val = readl_relaxed(priv->common.base + STM32F4_ADC_CCR);
val &= ~STM32F4_ADC_ADCPRE_MASK;
val |= i << STM32F4_ADC_ADCPRE_SHIFT;
@@ -104,6 +160,126 @@ static int stm32f4_adc_clk_sel(struct platform_device *pdev,
return 0;
}
+/**
+ * struct stm32h7_adc_ck_spec - specification for stm32h7 adc clock
+ * @ckmode: ADC clock mode, Async or sync with prescaler.
+ * @presc: prescaler bitfield for async clock mode
+ * @div: prescaler division ratio
+ */
+struct stm32h7_adc_ck_spec {
+ u32 ckmode;
+ u32 presc;
+ int div;
+};
+
+const struct stm32h7_adc_ck_spec stm32h7_adc_ckmodes_spec[] = {
+ /* 00: CK_ADC[1..3]: Asynchronous clock modes */
+ { 0, 0, 1 },
+ { 0, 1, 2 },
+ { 0, 2, 4 },
+ { 0, 3, 6 },
+ { 0, 4, 8 },
+ { 0, 5, 10 },
+ { 0, 6, 12 },
+ { 0, 7, 16 },
+ { 0, 8, 32 },
+ { 0, 9, 64 },
+ { 0, 10, 128 },
+ { 0, 11, 256 },
+ /* HCLK used: Synchronous clock modes (1, 2 or 4 prescaler) */
+ { 1, 0, 1 },
+ { 2, 0, 2 },
+ { 3, 0, 4 },
+};
+
+static int stm32h7_adc_clk_sel(struct platform_device *pdev,
+ struct stm32_adc_priv *priv)
+{
+ u32 ckmode, presc, val;
+ unsigned long rate;
+ int i, div;
+
+ /* stm32h7 bus clock is common for all ADC instances (mandatory) */
+ if (!priv->bclk) {
+ dev_err(&pdev->dev, "No 'bus' clock found\n");
+ return -ENOENT;
+ }
+
+ /*
+ * stm32h7 can use either 'bus' or 'adc' clock for analog circuitry.
+ * So, choice is to have bus clock mandatory and adc clock optional.
+ * If optional 'adc' clock has been found, then try to use it first.
+ */
+ if (priv->aclk) {
+ /*
+ * Asynchronous clock modes (e.g. ckmode == 0)
+ * From spec: PLL output musn't exceed max rate
+ */
+ rate = clk_get_rate(priv->aclk);
+
+ for (i = 0; i < ARRAY_SIZE(stm32h7_adc_ckmodes_spec); i++) {
+ ckmode = stm32h7_adc_ckmodes_spec[i].ckmode;
+ presc = stm32h7_adc_ckmodes_spec[i].presc;
+ div = stm32h7_adc_ckmodes_spec[i].div;
+
+ if (ckmode)
+ continue;
+
+ if ((rate / div) <= STM32H7_ADC_MAX_CLK_RATE)
+ goto out;
+ }
+ }
+
+ /* Synchronous clock modes (e.g. ckmode is 1, 2 or 3) */
+ rate = clk_get_rate(priv->bclk);
+
+ for (i = 0; i < ARRAY_SIZE(stm32h7_adc_ckmodes_spec); i++) {
+ ckmode = stm32h7_adc_ckmodes_spec[i].ckmode;
+ presc = stm32h7_adc_ckmodes_spec[i].presc;
+ div = stm32h7_adc_ckmodes_spec[i].div;
+
+ if (!ckmode)
+ continue;
+
+ if ((rate / div) <= STM32H7_ADC_MAX_CLK_RATE)
+ goto out;
+ }
+
+ dev_err(&pdev->dev, "adc clk selection failed\n");
+ return -EINVAL;
+
+out:
+ /* rate used later by each ADC instance to control BOOST mode */
+ priv->common.rate = rate;
+
+ /* Set common clock mode and prescaler */
+ val = readl_relaxed(priv->common.base + STM32H7_ADC_CCR);
+ val &= ~(STM32H7_CKMODE_MASK | STM32H7_PRESC_MASK);
+ val |= ckmode << STM32H7_CKMODE_SHIFT;
+ val |= presc << STM32H7_PRESC_SHIFT;
+ writel_relaxed(val, priv->common.base + STM32H7_ADC_CCR);
+
+ dev_dbg(&pdev->dev, "Using %s clock/%d source at %ld kHz\n",
+ ckmode ? "bus" : "adc", div, rate / (div * 1000));
+
+ return 0;
+}
+
+/* STM32F4 common registers definitions */
+static const struct stm32_adc_common_regs stm32f4_adc_common_regs = {
+ .csr = STM32F4_ADC_CSR,
+ .eoc1_msk = STM32F4_EOC1,
+ .eoc2_msk = STM32F4_EOC2,
+ .eoc3_msk = STM32F4_EOC3,
+};
+
+/* STM32H7 common registers definitions */
+static const struct stm32_adc_common_regs stm32h7_adc_common_regs = {
+ .csr = STM32H7_ADC_CSR,
+ .eoc1_msk = STM32H7_EOC_MST,
+ .eoc2_msk = STM32H7_EOC_SLV,
+};
+
/* ADC common interrupt for all instances */
static void stm32_adc_irq_handler(struct irq_desc *desc)
{
@@ -112,15 +288,15 @@ static void stm32_adc_irq_handler(struct irq_desc *desc)
u32 status;
chained_irq_enter(chip, desc);
- status = readl_relaxed(priv->common.base + STM32F4_ADC_CSR);
+ status = readl_relaxed(priv->common.base + priv->cfg->regs->csr);
- if (status & STM32F4_EOC1)
+ if (status & priv->cfg->regs->eoc1_msk)
generic_handle_irq(irq_find_mapping(priv->domain, 0));
- if (status & STM32F4_EOC2)
+ if (status & priv->cfg->regs->eoc2_msk)
generic_handle_irq(irq_find_mapping(priv->domain, 1));
- if (status & STM32F4_EOC3)
+ if (status & priv->cfg->regs->eoc3_msk)
generic_handle_irq(irq_find_mapping(priv->domain, 2));
chained_irq_exit(chip, desc);
@@ -186,6 +362,7 @@ static void stm32_adc_irq_remove(struct platform_device *pdev,
static int stm32_adc_probe(struct platform_device *pdev)
{
struct stm32_adc_priv *priv;
+ struct device *dev = &pdev->dev;
struct device_node *np = pdev->dev.of_node;
struct resource *res;
int ret;
@@ -197,6 +374,9 @@ static int stm32_adc_probe(struct platform_device *pdev)
if (!priv)
return -ENOMEM;
+ priv->cfg = (const struct stm32_adc_priv_cfg *)
+ of_match_device(dev->driver->of_match_table, dev)->data;
+
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
priv->common.base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(priv->common.base))
@@ -227,25 +407,48 @@ static int stm32_adc_probe(struct platform_device *pdev)
priv->aclk = devm_clk_get(&pdev->dev, "adc");
if (IS_ERR(priv->aclk)) {
ret = PTR_ERR(priv->aclk);
- dev_err(&pdev->dev, "Can't get 'adc' clock\n");
- goto err_regulator_disable;
+ if (ret == -ENOENT) {
+ priv->aclk = NULL;
+ } else {
+ dev_err(&pdev->dev, "Can't get 'adc' clock\n");
+ goto err_regulator_disable;
+ }
}
- ret = clk_prepare_enable(priv->aclk);
- if (ret < 0) {
- dev_err(&pdev->dev, "adc clk enable failed\n");
- goto err_regulator_disable;
+ if (priv->aclk) {
+ ret = clk_prepare_enable(priv->aclk);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "adc clk enable failed\n");
+ goto err_regulator_disable;
+ }
}
- ret = stm32f4_adc_clk_sel(pdev, priv);
- if (ret < 0) {
- dev_err(&pdev->dev, "adc clk selection failed\n");
- goto err_clk_disable;
+ priv->bclk = devm_clk_get(&pdev->dev, "bus");
+ if (IS_ERR(priv->bclk)) {
+ ret = PTR_ERR(priv->bclk);
+ if (ret == -ENOENT) {
+ priv->bclk = NULL;
+ } else {
+ dev_err(&pdev->dev, "Can't get 'bus' clock\n");
+ goto err_aclk_disable;
+ }
+ }
+
+ if (priv->bclk) {
+ ret = clk_prepare_enable(priv->bclk);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "adc clk enable failed\n");
+ goto err_aclk_disable;
+ }
}
+ ret = priv->cfg->clk_sel(pdev, priv);
+ if (ret < 0)
+ goto err_bclk_disable;
+
ret = stm32_adc_irq_probe(pdev, priv);
if (ret < 0)
- goto err_clk_disable;
+ goto err_bclk_disable;
platform_set_drvdata(pdev, &priv->common);
@@ -260,8 +463,13 @@ static int stm32_adc_probe(struct platform_device *pdev)
err_irq_remove:
stm32_adc_irq_remove(pdev, priv);
-err_clk_disable:
- clk_disable_unprepare(priv->aclk);
+err_bclk_disable:
+ if (priv->bclk)
+ clk_disable_unprepare(priv->bclk);
+
+err_aclk_disable:
+ if (priv->aclk)
+ clk_disable_unprepare(priv->aclk);
err_regulator_disable:
regulator_disable(priv->vref);
@@ -276,15 +484,34 @@ static int stm32_adc_remove(struct platform_device *pdev)
of_platform_depopulate(&pdev->dev);
stm32_adc_irq_remove(pdev, priv);
- clk_disable_unprepare(priv->aclk);
+ if (priv->bclk)
+ clk_disable_unprepare(priv->bclk);
+ if (priv->aclk)
+ clk_disable_unprepare(priv->aclk);
regulator_disable(priv->vref);
return 0;
}
+static const struct stm32_adc_priv_cfg stm32f4_adc_priv_cfg = {
+ .regs = &stm32f4_adc_common_regs,
+ .clk_sel = stm32f4_adc_clk_sel,
+};
+
+static const struct stm32_adc_priv_cfg stm32h7_adc_priv_cfg = {
+ .regs = &stm32h7_adc_common_regs,
+ .clk_sel = stm32h7_adc_clk_sel,
+};
+
static const struct of_device_id stm32_adc_of_match[] = {
- { .compatible = "st,stm32f4-adc-core" },
- {},
+ {
+ .compatible = "st,stm32f4-adc-core",
+ .data = (void *)&stm32f4_adc_priv_cfg
+ }, {
+ .compatible = "st,stm32h7-adc-core",
+ .data = (void *)&stm32h7_adc_priv_cfg
+ }, {
+ },
};
MODULE_DEVICE_TABLE(of, stm32_adc_of_match);