#include <linux/init.h>
#include <linux/io.h>
#include <linux/module.h>
+#include <linux/of_address.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
-/* Clock registers */
-#define BCM2835_CLK_PCMCTL_REG 0x00
-#define BCM2835_CLK_PCMDIV_REG 0x04
-
-/* Clock register settings */
-#define BCM2835_CLK_PASSWD (0x5a000000)
-#define BCM2835_CLK_PASSWD_MASK (0xff000000)
-#define BCM2835_CLK_MASH(v) ((v) << 9)
-#define BCM2835_CLK_FLIP BIT(8)
-#define BCM2835_CLK_BUSY BIT(7)
-#define BCM2835_CLK_KILL BIT(5)
-#define BCM2835_CLK_ENAB BIT(4)
-#define BCM2835_CLK_SRC(v) (v)
-
-#define BCM2835_CLK_SHIFT (12)
-#define BCM2835_CLK_DIVI(v) ((v) << BCM2835_CLK_SHIFT)
-#define BCM2835_CLK_DIVF(v) (v)
-#define BCM2835_CLK_DIVF_MASK (0xFFF)
-
-enum {
- BCM2835_CLK_MASH_0 = 0,
- BCM2835_CLK_MASH_1,
- BCM2835_CLK_MASH_2,
- BCM2835_CLK_MASH_3,
-};
-
-enum {
- BCM2835_CLK_SRC_GND = 0,
- BCM2835_CLK_SRC_OSC,
- BCM2835_CLK_SRC_DBG0,
- BCM2835_CLK_SRC_DBG1,
- BCM2835_CLK_SRC_PLLA,
- BCM2835_CLK_SRC_PLLC,
- BCM2835_CLK_SRC_PLLD,
- BCM2835_CLK_SRC_HDMI,
-};
-
-/* Most clocks are not useable (freq = 0) */
-static const unsigned int bcm2835_clk_freq[BCM2835_CLK_SRC_HDMI+1] = {
- [BCM2835_CLK_SRC_GND] = 0,
- [BCM2835_CLK_SRC_OSC] = 19200000,
- [BCM2835_CLK_SRC_DBG0] = 0,
- [BCM2835_CLK_SRC_DBG1] = 0,
- [BCM2835_CLK_SRC_PLLA] = 0,
- [BCM2835_CLK_SRC_PLLC] = 0,
- [BCM2835_CLK_SRC_PLLD] = 500000000,
- [BCM2835_CLK_SRC_HDMI] = 0,
-};
-
/* I2S registers */
#define BCM2835_I2S_CS_A_REG 0x00
#define BCM2835_I2S_FIFO_A_REG 0x04
#define BCM2835_I2S_INT_RXR BIT(1)
#define BCM2835_I2S_INT_TXW BIT(0)
-/* I2S DMA interface */
-/* FIXME: Needs IOMMU support */
-#define BCM2835_VCMMU_SHIFT (0x7E000000 - 0x20000000)
-
/* General device struct */
struct bcm2835_i2s_dev {
struct device *dev;
unsigned int fmt;
unsigned int bclk_ratio;
- struct regmap *i2s_regmap;
- struct regmap *clk_regmap;
+ struct regmap *i2s_regmap;
+ struct clk *clk;
+ bool clk_prepared;
};
static void bcm2835_i2s_start_clock(struct bcm2835_i2s_dev *dev)
{
- /* Start the clock if in master mode */
unsigned int master = dev->fmt & SND_SOC_DAIFMT_MASTER_MASK;
+ if (dev->clk_prepared)
+ return;
+
switch (master) {
case SND_SOC_DAIFMT_CBS_CFS:
case SND_SOC_DAIFMT_CBS_CFM:
- regmap_update_bits(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG,
- BCM2835_CLK_PASSWD_MASK | BCM2835_CLK_ENAB,
- BCM2835_CLK_PASSWD | BCM2835_CLK_ENAB);
+ clk_prepare_enable(dev->clk);
+ dev->clk_prepared = true;
break;
default:
break;
static void bcm2835_i2s_stop_clock(struct bcm2835_i2s_dev *dev)
{
- uint32_t clkreg;
- int timeout = 1000;
-
- /* Stop clock */
- regmap_update_bits(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG,
- BCM2835_CLK_PASSWD_MASK | BCM2835_CLK_ENAB,
- BCM2835_CLK_PASSWD);
-
- /* Wait for the BUSY flag going down */
- while (--timeout) {
- regmap_read(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG, &clkreg);
- if (!(clkreg & BCM2835_CLK_BUSY))
- break;
- }
-
- if (!timeout) {
- /* KILL the clock */
- dev_err(dev->dev, "I2S clock didn't stop. Kill the clock!\n");
- regmap_update_bits(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG,
- BCM2835_CLK_KILL | BCM2835_CLK_PASSWD_MASK,
- BCM2835_CLK_KILL | BCM2835_CLK_PASSWD);
- }
+ if (dev->clk_prepared)
+ clk_disable_unprepare(dev->clk);
+ dev->clk_prepared = false;
}
static void bcm2835_i2s_clear_fifos(struct bcm2835_i2s_dev *dev,
uint32_t syncval;
uint32_t csreg;
uint32_t i2s_active_state;
- uint32_t clkreg;
- uint32_t clk_active_state;
+ bool clk_was_prepared;
uint32_t off;
uint32_t clr;
regmap_read(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, &csreg);
i2s_active_state = csreg & (BCM2835_I2S_RXON | BCM2835_I2S_TXON);
- regmap_read(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG, &clkreg);
- clk_active_state = clkreg & BCM2835_CLK_ENAB;
-
/* Start clock if not running */
- if (!clk_active_state) {
- regmap_update_bits(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG,
- BCM2835_CLK_PASSWD_MASK | BCM2835_CLK_ENAB,
- BCM2835_CLK_PASSWD | BCM2835_CLK_ENAB);
- }
+ clk_was_prepared = dev->clk_prepared;
+ if (!clk_was_prepared)
+ bcm2835_i2s_start_clock(dev);
/* Stop I2S module */
regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, off, 0);
dev_err(dev->dev, "I2S SYNC error!\n");
/* Stop clock if it was not running before */
- if (!clk_active_state)
+ if (!clk_was_prepared)
bcm2835_i2s_stop_clock(dev);
/* Restore I2S state */
struct snd_soc_dai *dai)
{
struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
-
unsigned int sampling_rate = params_rate(params);
unsigned int data_length, data_delay, bclk_ratio;
unsigned int ch1pos, ch2pos, mode, format;
- unsigned int mash = BCM2835_CLK_MASH_1;
- unsigned int divi, divf, target_frequency;
- int clk_src = -1;
- unsigned int master = dev->fmt & SND_SOC_DAIFMT_MASTER_MASK;
- bool bit_master = (master == SND_SOC_DAIFMT_CBS_CFS
- || master == SND_SOC_DAIFMT_CBS_CFM);
-
- bool frame_master = (master == SND_SOC_DAIFMT_CBS_CFS
- || master == SND_SOC_DAIFMT_CBM_CFS);
uint32_t csreg;
/*
switch (params_format(params)) {
case SNDRV_PCM_FORMAT_S16_LE:
data_length = 16;
- bclk_ratio = 40;
break;
case SNDRV_PCM_FORMAT_S32_LE:
data_length = 32;
- bclk_ratio = 80;
break;
default:
return -EINVAL;
/* If bclk_ratio already set, use that one. */
if (dev->bclk_ratio)
bclk_ratio = dev->bclk_ratio;
+ else
+ /* otherwise calculate a fitting block ratio */
+ bclk_ratio = 2 * data_length;
- /*
- * Clock Settings
- *
- * The target frequency of the bit clock is
- * sampling rate * frame length
- *
- * Integer mode:
- * Sampling rates that are multiples of 8000 kHz
- * can be driven by the oscillator of 19.2 MHz
- * with an integer divider as long as the frame length
- * is an integer divider of 19200000/8000=2400 as set up above.
- * This is no longer possible if the sampling rate
- * is too high (e.g. 192 kHz), because the oscillator is too slow.
- *
- * MASH mode:
- * For all other sampling rates, it is not possible to
- * have an integer divider. Approximate the clock
- * with the MASH module that induces a slight frequency
- * variance. To minimize that it is best to have the fastest
- * clock here. That is PLLD with 500 MHz.
- */
- target_frequency = sampling_rate * bclk_ratio;
- clk_src = BCM2835_CLK_SRC_OSC;
- mash = BCM2835_CLK_MASH_0;
-
- if (bcm2835_clk_freq[clk_src] % target_frequency == 0
- && bit_master && frame_master) {
- divi = bcm2835_clk_freq[clk_src] / target_frequency;
- divf = 0;
- } else {
- uint64_t dividend;
-
- if (!dev->bclk_ratio) {
- /*
- * Overwrite bclk_ratio, because the
- * above trick is not needed or can
- * not be used.
- */
- bclk_ratio = 2 * data_length;
- }
-
- target_frequency = sampling_rate * bclk_ratio;
-
- clk_src = BCM2835_CLK_SRC_PLLD;
- mash = BCM2835_CLK_MASH_1;
-
- dividend = bcm2835_clk_freq[clk_src];
- dividend <<= BCM2835_CLK_SHIFT;
- do_div(dividend, target_frequency);
- divi = dividend >> BCM2835_CLK_SHIFT;
- divf = dividend & BCM2835_CLK_DIVF_MASK;
- }
-
- /* Set clock divider */
- regmap_write(dev->clk_regmap, BCM2835_CLK_PCMDIV_REG, BCM2835_CLK_PASSWD
- | BCM2835_CLK_DIVI(divi)
- | BCM2835_CLK_DIVF(divf));
-
- /* Setup clock, but don't start it yet */
- regmap_write(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG, BCM2835_CLK_PASSWD
- | BCM2835_CLK_MASH(mash)
- | BCM2835_CLK_SRC(clk_src));
+ /* set target clock rate*/
+ clk_set_rate(dev->clk, sampling_rate * bclk_ratio);
/* Setup the frame format */
format = BCM2835_I2S_CHEN;
.trigger = bcm2835_i2s_trigger,
.hw_params = bcm2835_i2s_hw_params,
.set_fmt = bcm2835_i2s_set_dai_fmt,
- .set_bclk_ratio = bcm2835_i2s_set_dai_bclk_ratio
+ .set_bclk_ratio = bcm2835_i2s_set_dai_bclk_ratio,
};
static int bcm2835_i2s_dai_probe(struct snd_soc_dai *dai)
};
}
-static bool bcm2835_clk_volatile_reg(struct device *dev, unsigned int reg)
-{
- switch (reg) {
- case BCM2835_CLK_PCMCTL_REG:
- return true;
- default:
- return false;
- };
-}
-
-static const struct regmap_config bcm2835_regmap_config[] = {
- {
- .reg_bits = 32,
- .reg_stride = 4,
- .val_bits = 32,
- .max_register = BCM2835_I2S_GRAY_REG,
- .precious_reg = bcm2835_i2s_precious_reg,
- .volatile_reg = bcm2835_i2s_volatile_reg,
- .cache_type = REGCACHE_RBTREE,
- },
- {
- .reg_bits = 32,
- .reg_stride = 4,
- .val_bits = 32,
- .max_register = BCM2835_CLK_PCMDIV_REG,
- .volatile_reg = bcm2835_clk_volatile_reg,
- .cache_type = REGCACHE_RBTREE,
- },
+static const struct regmap_config bcm2835_regmap_config = {
+ .reg_bits = 32,
+ .reg_stride = 4,
+ .val_bits = 32,
+ .max_register = BCM2835_I2S_GRAY_REG,
+ .precious_reg = bcm2835_i2s_precious_reg,
+ .volatile_reg = bcm2835_i2s_volatile_reg,
+ .cache_type = REGCACHE_RBTREE,
};
static const struct snd_soc_component_driver bcm2835_i2s_component = {
static int bcm2835_i2s_probe(struct platform_device *pdev)
{
struct bcm2835_i2s_dev *dev;
- int i;
int ret;
- struct regmap *regmap[2];
- struct resource *mem[2];
-
- /* Request both ioareas */
- for (i = 0; i <= 1; i++) {
- void __iomem *base;
-
- mem[i] = platform_get_resource(pdev, IORESOURCE_MEM, i);
- base = devm_ioremap_resource(&pdev->dev, mem[i]);
- if (IS_ERR(base))
- return PTR_ERR(base);
-
- regmap[i] = devm_regmap_init_mmio(&pdev->dev, base,
- &bcm2835_regmap_config[i]);
- if (IS_ERR(regmap[i]))
- return PTR_ERR(regmap[i]);
- }
+ struct resource *mem;
+ void __iomem *base;
+ const __be32 *addr;
+ dma_addr_t dma_base;
dev = devm_kzalloc(&pdev->dev, sizeof(*dev),
GFP_KERNEL);
if (!dev)
return -ENOMEM;
- dev->i2s_regmap = regmap[0];
- dev->clk_regmap = regmap[1];
+ /* get the clock */
+ dev->clk_prepared = false;
+ dev->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(dev->clk)) {
+ dev_err(&pdev->dev, "could not get clk: %ld\n",
+ PTR_ERR(dev->clk));
+ return PTR_ERR(dev->clk);
+ }
+
+ /* Request ioarea */
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ base = devm_ioremap_resource(&pdev->dev, mem);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ dev->i2s_regmap = devm_regmap_init_mmio(&pdev->dev, base,
+ &bcm2835_regmap_config);
+ if (IS_ERR(dev->i2s_regmap))
+ return PTR_ERR(dev->i2s_regmap);
+
+ /* Set the DMA address - we have to parse DT ourselves */
+ addr = of_get_address(pdev->dev.of_node, 0, NULL, NULL);
+ if (!addr) {
+ dev_err(&pdev->dev, "could not get DMA-register address\n");
+ return -EINVAL;
+ }
+ dma_base = be32_to_cpup(addr);
- /* Set the DMA address */
dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK].addr =
- (dma_addr_t)mem[0]->start + BCM2835_I2S_FIFO_A_REG
- + BCM2835_VCMMU_SHIFT;
+ dma_base + BCM2835_I2S_FIFO_A_REG;
dev->dma_data[SNDRV_PCM_STREAM_CAPTURE].addr =
- (dma_addr_t)mem[0]->start + BCM2835_I2S_FIFO_A_REG
- + BCM2835_VCMMU_SHIFT;
+ dma_base + BCM2835_I2S_FIFO_A_REG;
/* Set the bus width */
dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK].addr_width =