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path: root/drivers/spi/spi-pl022.c
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Diffstat (limited to 'drivers/spi/spi-pl022.c')
-rw-r--r--drivers/spi/spi-pl022.c58
1 files changed, 34 insertions, 24 deletions
diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
index 09c925aaf320..400ae2121a2a 100644
--- a/drivers/spi/spi-pl022.c
+++ b/drivers/spi/spi-pl022.c
@@ -1667,9 +1667,15 @@ static int calculate_effective_freq(struct pl022 *pl022, int freq, struct
1667 /* cpsdvsr = 254 & scr = 255 */ 1667 /* cpsdvsr = 254 & scr = 255 */
1668 min_tclk = spi_rate(rate, CPSDVR_MAX, SCR_MAX); 1668 min_tclk = spi_rate(rate, CPSDVR_MAX, SCR_MAX);
1669 1669
1670 if (!((freq <= max_tclk) && (freq >= min_tclk))) { 1670 if (freq > max_tclk)
1671 dev_warn(&pl022->adev->dev,
1672 "Max speed that can be programmed is %d Hz, you requested %d\n",
1673 max_tclk, freq);
1674
1675 if (freq < min_tclk) {
1671 dev_err(&pl022->adev->dev, 1676 dev_err(&pl022->adev->dev,
1672 "controller data is incorrect: out of range frequency"); 1677 "Requested frequency: %d Hz is less than minimum possible %d Hz\n",
1678 freq, min_tclk);
1673 return -EINVAL; 1679 return -EINVAL;
1674 } 1680 }
1675 1681
@@ -1681,26 +1687,37 @@ static int calculate_effective_freq(struct pl022 *pl022, int freq, struct
1681 while (scr <= SCR_MAX) { 1687 while (scr <= SCR_MAX) {
1682 tmp = spi_rate(rate, cpsdvsr, scr); 1688 tmp = spi_rate(rate, cpsdvsr, scr);
1683 1689
1684 if (tmp > freq) 1690 if (tmp > freq) {
1691 /* we need lower freq */
1685 scr++; 1692 scr++;
1693 continue;
1694 }
1695
1686 /* 1696 /*
1687 * If found exact value, update and break. 1697 * If found exact value, mark found and break.
1688 * If found more closer value, update and continue. 1698 * If found more closer value, update and break.
1689 */ 1699 */
1690 else if ((tmp == freq) || (tmp > best_freq)) { 1700 if (tmp > best_freq) {
1691 best_freq = tmp; 1701 best_freq = tmp;
1692 best_cpsdvsr = cpsdvsr; 1702 best_cpsdvsr = cpsdvsr;
1693 best_scr = scr; 1703 best_scr = scr;
1694 1704
1695 if (tmp == freq) 1705 if (tmp == freq)
1696 break; 1706 found = 1;
1697 } 1707 }
1698 scr++; 1708 /*
1709 * increased scr will give lower rates, which are not
1710 * required
1711 */
1712 break;
1699 } 1713 }
1700 cpsdvsr += 2; 1714 cpsdvsr += 2;
1701 scr = SCR_MIN; 1715 scr = SCR_MIN;
1702 } 1716 }
1703 1717
1718 WARN(!best_freq, "pl022: Matching cpsdvsr and scr not found for %d Hz rate \n",
1719 freq);
1720
1704 clk_freq->cpsdvsr = (u8) (best_cpsdvsr & 0xFF); 1721 clk_freq->cpsdvsr = (u8) (best_cpsdvsr & 0xFF);
1705 clk_freq->scr = (u8) (best_scr & 0xFF); 1722 clk_freq->scr = (u8) (best_scr & 0xFF);
1706 dev_dbg(&pl022->adev->dev, 1723 dev_dbg(&pl022->adev->dev,
@@ -1823,9 +1840,12 @@ static int pl022_setup(struct spi_device *spi)
1823 } else 1840 } else
1824 chip->cs_control = chip_info->cs_control; 1841 chip->cs_control = chip_info->cs_control;
1825 1842
1826 if (bits <= 3) { 1843 /* Check bits per word with vendor specific range */
1827 /* PL022 doesn't support less than 4-bits */ 1844 if ((bits <= 3) || (bits > pl022->vendor->max_bpw)) {
1828 status = -ENOTSUPP; 1845 status = -ENOTSUPP;
1846 dev_err(&spi->dev, "illegal data size for this controller!\n");
1847 dev_err(&spi->dev, "This controller can only handle 4 <= n <= %d bit words\n",
1848 pl022->vendor->max_bpw);
1829 goto err_config_params; 1849 goto err_config_params;
1830 } else if (bits <= 8) { 1850 } else if (bits <= 8) {
1831 dev_dbg(&spi->dev, "4 <= n <=8 bits per word\n"); 1851 dev_dbg(&spi->dev, "4 <= n <=8 bits per word\n");
@@ -1838,20 +1858,10 @@ static int pl022_setup(struct spi_device *spi)
1838 chip->read = READING_U16; 1858 chip->read = READING_U16;
1839 chip->write = WRITING_U16; 1859 chip->write = WRITING_U16;
1840 } else { 1860 } else {
1841 if (pl022->vendor->max_bpw >= 32) { 1861 dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n");
1842 dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n"); 1862 chip->n_bytes = 4;
1843 chip->n_bytes = 4; 1863 chip->read = READING_U32;
1844 chip->read = READING_U32; 1864 chip->write = WRITING_U32;
1845 chip->write = WRITING_U32;
1846 } else {
1847 dev_err(&spi->dev,
1848 "illegal data size for this controller!\n");
1849 dev_err(&spi->dev,
1850 "a standard pl022 can only handle "
1851 "1 <= n <= 16 bit words\n");
1852 status = -ENOTSUPP;
1853 goto err_config_params;
1854 }
1855 } 1865 }
1856 1866
1857 /* Now Initialize all register settings required for this chip */ 1867 /* Now Initialize all register settings required for this chip */