/** * struct stm32_adc_common_regs - stm32 common registers * @csr: common status register offset * @ccr: common control register offset * @eoc_msk: array of eoc (end of conversion flag) masks in csr for adc1..n * @ovr_msk: array of ovr (overrun flag) masks in csr for adc1..n * @ier: interrupt enable register offset for each adc * @eocie_msk: end of conversion interrupt enable mask in @ier
*/ struct stm32_adc_common_regs {
u32 csr;
u32 ccr;
u32 eoc_msk[STM32_ADC_MAX_ADCS];
u32 ovr_msk[STM32_ADC_MAX_ADCS];
u32 ier;
u32 eocie_msk;
};
struct stm32_adc_priv;
/** * struct stm32_adc_priv_cfg - stm32 core compatible configuration data * @regs: common registers for all instances * @clk_sel: clock selection routine * @max_clk_rate_hz: maximum analog clock rate (Hz, from datasheet) * @ipid: adc identification number * @has_syscfg: SYSCFG capability flags * @num_irqs: number of interrupt lines * @num_adcs: maximum number of ADC instances in the common registers
*/ struct stm32_adc_priv_cfg { conststruct stm32_adc_common_regs *regs; int (*clk_sel)(struct platform_device *, struct stm32_adc_priv *);
u32 max_clk_rate_hz;
u32 ipid; unsignedint has_syscfg; unsignedint num_irqs; unsignedint num_adcs;
};
/** * struct stm32_adc_priv - stm32 ADC core private data * @irq: irq(s) for ADC block * @nb_adc_max: actual maximum number of instance per ADC block * @domain: irq domain reference * @aclk: clock reference for the analog circuitry * @bclk: bus clock common for all ADCs, depends on part used * @max_clk_rate: desired maximum clock rate * @booster: booster supply reference * @vdd: vdd supply reference * @vdda: vdda analog supply reference * @vref: regulator reference * @vdd_uv: vdd supply voltage (microvolts) * @vdda_uv: vdda supply voltage (microvolts) * @cfg: compatible configuration data * @common: common data for all ADC instances * @ccr_bak: backup CCR in low power mode * @syscfg: reference to syscon, system control registers
*/ struct stm32_adc_priv { int irq[STM32_ADC_MAX_ADCS]; unsignedint nb_adc_max; struct irq_domain *domain; struct clk *aclk; struct clk *bclk;
u32 max_clk_rate; struct regulator *booster; struct regulator *vdd; struct regulator *vdda; struct regulator *vref; int vdd_uv; int vdda_uv; conststruct stm32_adc_priv_cfg *cfg; struct stm32_adc_common common;
u32 ccr_bak; struct regmap *syscfg;
};
/** * stm32f4_adc_clk_sel() - Select stm32f4 ADC common clock prescaler * @pdev: platform device * @priv: stm32 ADC core private data * Select clock prescaler used for analog conversions, before using ADC.
*/ staticint stm32f4_adc_clk_sel(struct platform_device *pdev, struct stm32_adc_priv *priv)
{ unsignedlong rate;
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;
}
for (i = 0; i < ARRAY_SIZE(stm32f4_pclk_div); i++) { if ((rate / stm32f4_pclk_div[i]) <= priv->max_clk_rate) break;
} if (i >= ARRAY_SIZE(stm32f4_pclk_div)) {
dev_err(&pdev->dev, "adc clk selection failed\n"); return -EINVAL;
}
priv->common.rate = rate / stm32f4_pclk_div[i];
val = readl_relaxed(priv->common.base + STM32F4_ADC_CCR);
val &= ~STM32F4_ADC_ADCPRE_MASK;
val |= i << STM32F4_ADC_ADCPRE_SHIFT;
writel_relaxed(val, priv->common.base + STM32F4_ADC_CCR);
dev_dbg(&pdev->dev, "Using analog clock source at %ld kHz\n",
priv->common.rate / 1000);
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;
};
staticint stm32h7_adc_clk_sel(struct platform_device *pdev, struct stm32_adc_priv *priv)
{
u32 ckmode, presc, val; unsignedlong rate; int i, div, duty;
/* 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); if (!rate) {
dev_err(&pdev->dev, "Invalid adc clock rate: 0\n"); return -EINVAL;
}
/* If duty is an error, kindly use at least /2 divider */
duty = clk_get_scaled_duty_cycle(priv->aclk, 100); if (duty < 0)
dev_warn(&pdev->dev, "adc clock duty: %d\n", duty);
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;
/* * For proper operation, clock duty cycle range is 49% * to 51%. Apply at least /2 prescaler otherwise.
*/ if (div == 1 && (duty < 49 || duty > 51)) continue;
if ((rate / div) <= priv->max_clk_rate) goto out;
}
}
/* Synchronous clock modes (e.g. ckmode is 1, 2 or 3) */
rate = clk_get_rate(priv->bclk); if (!rate) {
dev_err(&pdev->dev, "Invalid bus clock rate: 0\n"); return -EINVAL;
}
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;
out: /* rate used later by each ADC instance to control BOOST mode */
priv->common.rate = rate / div;
/* 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);
/* ADC common interrupt for all instances */ staticvoid stm32_adc_irq_handler(struct irq_desc *desc)
{ struct stm32_adc_priv *priv = irq_desc_get_handler_data(desc); struct irq_chip *chip = irq_desc_get_chip(desc); int i;
u32 status;
chained_irq_enter(chip, desc);
status = readl_relaxed(priv->common.base + priv->cfg->regs->csr);
/* * End of conversion may be handled by using IRQ or DMA. There may be a * race here when two conversions complete at the same time on several * ADCs. EOC may be read 'set' for several ADCs, with: * - an ADC configured to use DMA (EOC triggers the DMA request, and * is then automatically cleared by DR read in hardware) * - an ADC configured to use IRQs (EOCIE bit is set. The handler must * be called in this case) * So both EOC status bit in CSR and EOCIE control bit must be checked * before invoking the interrupt handler (e.g. call ISR only for * IRQ-enabled ADCs).
*/ for (i = 0; i < priv->nb_adc_max; i++) { if ((status & priv->cfg->regs->eoc_msk[i] &&
stm32_adc_eoc_enabled(priv, i)) ||
(status & priv->cfg->regs->ovr_msk[i]))
generic_handle_domain_irq(priv->domain, i);
}
/* * Interrupt(s) must be provided, depending on the compatible: * - stm32f4/h7 shares a common interrupt line. * - stm32mp1, has one line per ADC
*/ for (i = 0; i < priv->cfg->num_irqs; i++) {
priv->irq[i] = platform_get_irq(pdev, i); if (priv->irq[i] < 0) return priv->irq[i];
}
priv->domain = irq_domain_create_simple(dev_fwnode(&pdev->dev),
STM32_ADC_MAX_ADCS, 0,
&stm32_adc_domain_ops,
priv); if (!priv->domain) {
dev_err(&pdev->dev, "Failed to add irq domain\n"); return -ENOMEM;
}
for (i = 0; i < priv->cfg->num_irqs; i++)
irq_set_chained_handler_and_data(priv->irq[i],
stm32_adc_irq_handler, priv);
for (i = 0; i < priv->cfg->num_irqs; i++)
irq_set_chained_handler(priv->irq[i], NULL);
}
staticint stm32_adc_core_switches_supply_en(struct stm32_adc_priv *priv, struct device *dev)
{ int ret;
/* * On STM32H7 and STM32MP1, the ADC inputs are multiplexed with analog * switches (via PCSEL) which have reduced performances when their * supply is below 2.7V (vdda by default): * - Voltage booster can be used, to get full ADC performances * (increases power consumption). * - Vdd can be used to supply them, if above 2.7V (STM32MP1 only). * * Recommended settings for ANASWVDD and EN_BOOSTER: * - vdda < 2.7V but vdd > 2.7V: ANASWVDD = 1, EN_BOOSTER = 0 (stm32mp1) * - vdda < 2.7V and vdd < 2.7V: ANASWVDD = 0, EN_BOOSTER = 1 * - vdda >= 2.7V: ANASWVDD = 0, EN_BOOSTER = 0 (default)
*/ if (priv->vdda_uv < 2700000) { if (priv->syscfg && priv->vdd_uv > 2700000) {
ret = regulator_enable(priv->vdd); if (ret < 0) {
dev_err(dev, "vdd enable failed %d\n", ret); return ret;
}
ret = regmap_write(priv->syscfg,
STM32MP1_SYSCFG_PMCSETR,
STM32MP1_SYSCFG_ANASWVDD_MASK); if (ret < 0) {
regulator_disable(priv->vdd);
dev_err(dev, "vdd select failed, %d\n", ret); return ret;
}
dev_dbg(dev, "analog switches supplied by vdd\n");
return 0;
}
if (priv->booster) { /* * This is optional, as this is a trade-off between * analog performance and power consumption.
*/
ret = regulator_enable(priv->booster); if (ret < 0) {
dev_err(dev, "booster enable failed %d\n", ret); return ret;
}
dev_dbg(dev, "analog switches supplied by booster\n");
return 0;
}
}
/* Fallback using vdda (default), nothing to do */
dev_dbg(dev, "analog switches supplied by vdda (%d uV)\n",
priv->vdda_uv);
return 0;
}
staticvoid stm32_adc_core_switches_supply_dis(struct stm32_adc_priv *priv)
{ if (priv->vdda_uv < 2700000) { if (priv->syscfg && priv->vdd_uv > 2700000) {
regmap_write(priv->syscfg, STM32MP1_SYSCFG_PMCCLRR,
STM32MP1_SYSCFG_ANASWVDD_MASK);
regulator_disable(priv->vdd); return;
} if (priv->booster)
regulator_disable(priv->booster);
}
}
/* Backup CCR that may be lost (depends on power state to achieve) */
priv->ccr_bak = readl_relaxed(priv->common.base + priv->cfg->regs->ccr);
clk_disable_unprepare(priv->aclk);
clk_disable_unprepare(priv->bclk);
regulator_disable(priv->vref);
stm32_adc_core_switches_supply_dis(priv);
regulator_disable(priv->vdda);
}
/* Analog switches supply can be controlled by syscfg (optional) */
priv->syscfg = syscon_regmap_lookup_by_phandle(np, "st,syscfg"); if (IS_ERR(priv->syscfg)) {
ret = PTR_ERR(priv->syscfg); if (ret != -ENODEV) return dev_err_probe(dev, ret, "Can't probe syscfg\n");
priv->syscfg = NULL;
}
/* Booster can be used to supply analog switches (optional) */ if (priv->cfg->has_syscfg & HAS_VBOOSTER) {
priv->booster = devm_regulator_get_optional(dev, "booster"); if (IS_ERR(priv->booster)) {
ret = PTR_ERR(priv->booster); if (ret != -ENODEV) return dev_err_probe(dev, ret, "can't get booster\n");
priv->booster = NULL;
}
}
/* Vdd can be used to supply analog switches (optional) */ if (priv->cfg->has_syscfg & HAS_ANASWVDD) {
priv->vdd = devm_regulator_get_optional(dev, "vdd"); if (IS_ERR(priv->vdd)) {
ret = PTR_ERR(priv->vdd); if (ret != -ENODEV) return dev_err_probe(dev, ret, "can't get vdd\n");
priv->vdd = NULL;
}
}
if (priv->vdd) {
ret = regulator_enable(priv->vdd); if (ret < 0) {
dev_err(dev, "vdd enable failed %d\n", ret); return ret;
}
ret = regulator_get_voltage(priv->vdd); if (ret < 0) {
dev_err(dev, "vdd get voltage failed %d\n", ret);
regulator_disable(priv->vdd); return ret;
}
priv->vdd_uv = ret;
id = FIELD_GET(STM32MP1_IPIDR_MASK,
readl_relaxed(priv->common.base + STM32MP1_ADC_IPDR)); if (id != priv->cfg->ipid) {
dev_err(&pdev->dev, "Unexpected IP version: 0x%x", id); return -EINVAL;
}
for_each_child_of_node(np, child) {
ret = of_property_read_string(child, "compatible", &compat); if (ret) continue; /* Count child nodes with stm32 adc compatible */ if (strstr(compat, "st,stm32") && strstr(compat, "adc"))
count++;
}
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