--- /dev/null
+/*
+ * drivers/media/video/smiapp-pll.c
+ *
+ * Generic driver for SMIA/SMIA++ compliant camera modules
+ *
+ * Copyright (C) 2011--2012 Nokia Corporation
+ * Contact: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#include <linux/gcd.h>
+#include <linux/lcm.h>
+#include <linux/module.h>
+
+#include "smiapp-pll.h"
+
+/* Return an even number or one. */
+static inline uint32_t clk_div_even(uint32_t a)
+{
+ return max_t(uint32_t, 1, a & ~1);
+}
+
+/* Return an even number or one. */
+static inline uint32_t clk_div_even_up(uint32_t a)
+{
+ if (a == 1)
+ return 1;
+ return (a + 1) & ~1;
+}
+
+static inline uint32_t is_one_or_even(uint32_t a)
+{
+ if (a == 1)
+ return 1;
+ if (a & 1)
+ return 0;
+
+ return 1;
+}
+
+static int bounds_check(struct device *dev, uint32_t val,
+ uint32_t min, uint32_t max, char *str)
+{
+ if (val >= min && val <= max)
+ return 0;
+
+ dev_warn(dev, "%s out of bounds: %d (%d--%d)\n", str, val, min, max);
+
+ return -EINVAL;
+}
+
+static void print_pll(struct device *dev, struct smiapp_pll *pll)
+{
+ dev_dbg(dev, "pre_pll_clk_div\t%d\n", pll->pre_pll_clk_div);
+ dev_dbg(dev, "pll_multiplier \t%d\n", pll->pll_multiplier);
+ if (pll->flags != SMIAPP_PLL_FLAG_NO_OP_CLOCKS) {
+ dev_dbg(dev, "op_sys_clk_div \t%d\n", pll->op_sys_clk_div);
+ dev_dbg(dev, "op_pix_clk_div \t%d\n", pll->op_pix_clk_div);
+ }
+ dev_dbg(dev, "vt_sys_clk_div \t%d\n", pll->vt_sys_clk_div);
+ dev_dbg(dev, "vt_pix_clk_div \t%d\n", pll->vt_pix_clk_div);
+
+ dev_dbg(dev, "ext_clk_freq_hz \t%d\n", pll->ext_clk_freq_hz);
+ dev_dbg(dev, "pll_ip_clk_freq_hz \t%d\n", pll->pll_ip_clk_freq_hz);
+ dev_dbg(dev, "pll_op_clk_freq_hz \t%d\n", pll->pll_op_clk_freq_hz);
+ if (pll->flags & SMIAPP_PLL_FLAG_NO_OP_CLOCKS) {
+ dev_dbg(dev, "op_sys_clk_freq_hz \t%d\n",
+ pll->op_sys_clk_freq_hz);
+ dev_dbg(dev, "op_pix_clk_freq_hz \t%d\n",
+ pll->op_pix_clk_freq_hz);
+ }
+ dev_dbg(dev, "vt_sys_clk_freq_hz \t%d\n", pll->vt_sys_clk_freq_hz);
+ dev_dbg(dev, "vt_pix_clk_freq_hz \t%d\n", pll->vt_pix_clk_freq_hz);
+}
+
+int smiapp_pll_calculate(struct device *dev, struct smiapp_pll_limits *limits,
+ struct smiapp_pll *pll)
+{
+ uint32_t sys_div;
+ uint32_t best_pix_div = INT_MAX >> 1;
+ uint32_t vt_op_binning_div;
+ uint32_t lane_op_clock_ratio;
+ uint32_t mul, div;
+ uint32_t more_mul_min, more_mul_max;
+ uint32_t more_mul_factor;
+ uint32_t min_vt_div, max_vt_div, vt_div;
+ uint32_t min_sys_div, max_sys_div;
+ unsigned int i;
+ int rval;
+
+ if (pll->flags & SMIAPP_PLL_FLAG_OP_PIX_CLOCK_PER_LANE)
+ lane_op_clock_ratio = pll->lanes;
+ else
+ lane_op_clock_ratio = 1;
+ dev_dbg(dev, "lane_op_clock_ratio: %d\n", lane_op_clock_ratio);
+
+ dev_dbg(dev, "binning: %dx%d\n", pll->binning_horizontal,
+ pll->binning_vertical);
+
+ /* CSI transfers 2 bits per clock per lane; thus times 2 */
+ pll->pll_op_clk_freq_hz = pll->link_freq * 2
+ * (pll->lanes / lane_op_clock_ratio);
+
+ /* Figure out limits for pre-pll divider based on extclk */
+ dev_dbg(dev, "min / max pre_pll_clk_div: %d / %d\n",
+ limits->min_pre_pll_clk_div, limits->max_pre_pll_clk_div);
+ limits->max_pre_pll_clk_div =
+ min_t(uint16_t, limits->max_pre_pll_clk_div,
+ clk_div_even(pll->ext_clk_freq_hz /
+ limits->min_pll_ip_freq_hz));
+ limits->min_pre_pll_clk_div =
+ max_t(uint16_t, limits->min_pre_pll_clk_div,
+ clk_div_even(pll->ext_clk_freq_hz /
+ limits->max_pll_ip_freq_hz));
+ dev_dbg(dev, "pre-pll check: min / max pre_pll_clk_div: %d / %d\n",
+ limits->min_pre_pll_clk_div, limits->max_pre_pll_clk_div);
+
+ i = gcd(pll->pll_op_clk_freq_hz, pll->ext_clk_freq_hz);
+ mul = div_u64(pll->pll_op_clk_freq_hz, i);
+ div = pll->ext_clk_freq_hz / i;
+ dev_dbg(dev, "mul %d / div %d\n", mul, div);
+
+ limits->min_pre_pll_clk_div =
+ max_t(uint16_t, limits->min_pre_pll_clk_div,
+ clk_div_even_up(
+ DIV_ROUND_UP(mul * pll->ext_clk_freq_hz,
+ limits->max_pll_op_freq_hz)));
+ dev_dbg(dev, "pll_op check: min / max pre_pll_clk_div: %d / %d\n",
+ limits->min_pre_pll_clk_div, limits->max_pre_pll_clk_div);
+
+ if (limits->min_pre_pll_clk_div > limits->max_pre_pll_clk_div) {
+ dev_err(dev, "unable to compute pre_pll divisor\n");
+ return -EINVAL;
+ }
+
+ pll->pre_pll_clk_div = limits->min_pre_pll_clk_div;
+
+ /*
+ * Get pre_pll_clk_div so that our pll_op_clk_freq_hz won't be
+ * too high.
+ */
+ dev_dbg(dev, "pre_pll_clk_div %d\n", pll->pre_pll_clk_div);
+
+ /* Don't go above max pll multiplier. */
+ more_mul_max = limits->max_pll_multiplier / mul;
+ dev_dbg(dev, "more_mul_max: max_pll_multiplier check: %d\n",
+ more_mul_max);
+ /* Don't go above max pll op frequency. */
+ more_mul_max =
+ min_t(int,
+ more_mul_max,
+ limits->max_pll_op_freq_hz
+ / (pll->ext_clk_freq_hz / pll->pre_pll_clk_div * mul));
+ dev_dbg(dev, "more_mul_max: max_pll_op_freq_hz check: %d\n",
+ more_mul_max);
+ /* Don't go above the division capability of op sys clock divider. */
+ more_mul_max = min(more_mul_max,
+ limits->max_op_sys_clk_div * pll->pre_pll_clk_div
+ / div);
+ dev_dbg(dev, "more_mul_max: max_op_sys_clk_div check: %d\n",
+ more_mul_max);
+ /* Ensure we won't go above min_pll_multiplier. */
+ more_mul_max = min(more_mul_max,
+ DIV_ROUND_UP(limits->max_pll_multiplier, mul));
+ dev_dbg(dev, "more_mul_max: min_pll_multiplier check: %d\n",
+ more_mul_max);
+
+ /* Ensure we won't go below min_pll_op_freq_hz. */
+ more_mul_min = DIV_ROUND_UP(limits->min_pll_op_freq_hz,
+ pll->ext_clk_freq_hz / pll->pre_pll_clk_div
+ * mul);
+ dev_dbg(dev, "more_mul_min: min_pll_op_freq_hz check: %d\n",
+ more_mul_min);
+ /* Ensure we won't go below min_pll_multiplier. */
+ more_mul_min = max(more_mul_min,
+ DIV_ROUND_UP(limits->min_pll_multiplier, mul));
+ dev_dbg(dev, "more_mul_min: min_pll_multiplier check: %d\n",
+ more_mul_min);
+
+ if (more_mul_min > more_mul_max) {
+ dev_warn(dev,
+ "unable to compute more_mul_min and more_mul_max");
+ return -EINVAL;
+ }
+
+ more_mul_factor = lcm(div, pll->pre_pll_clk_div) / div;
+ dev_dbg(dev, "more_mul_factor: %d\n", more_mul_factor);
+ more_mul_factor = lcm(more_mul_factor, limits->min_op_sys_clk_div);
+ dev_dbg(dev, "more_mul_factor: min_op_sys_clk_div: %d\n",
+ more_mul_factor);
+ i = roundup(more_mul_min, more_mul_factor);
+ if (!is_one_or_even(i))
+ i <<= 1;
+
+ dev_dbg(dev, "final more_mul: %d\n", i);
+ if (i > more_mul_max) {
+ dev_warn(dev, "final more_mul is bad, max %d", more_mul_max);
+ return -EINVAL;
+ }
+
+ pll->pll_multiplier = mul * i;
+ pll->op_sys_clk_div = div * i / pll->pre_pll_clk_div;
+ dev_dbg(dev, "op_sys_clk_div: %d\n", pll->op_sys_clk_div);
+
+ pll->pll_ip_clk_freq_hz = pll->ext_clk_freq_hz
+ / pll->pre_pll_clk_div;
+
+ pll->pll_op_clk_freq_hz = pll->pll_ip_clk_freq_hz
+ * pll->pll_multiplier;
+
+ /* Derive pll_op_clk_freq_hz. */
+ pll->op_sys_clk_freq_hz =
+ pll->pll_op_clk_freq_hz / pll->op_sys_clk_div;
+
+ pll->op_pix_clk_div = pll->bits_per_pixel;
+ dev_dbg(dev, "op_pix_clk_div: %d\n", pll->op_pix_clk_div);
+
+ pll->op_pix_clk_freq_hz =
+ pll->op_sys_clk_freq_hz / pll->op_pix_clk_div;
+
+ /*
+ * Some sensors perform analogue binning and some do this
+ * digitally. The ones doing this digitally can be roughly be
+ * found out using this formula. The ones doing this digitally
+ * should run at higher clock rate, so smaller divisor is used
+ * on video timing side.
+ */
+ if (limits->min_line_length_pck_bin > limits->min_line_length_pck
+ / pll->binning_horizontal)
+ vt_op_binning_div = pll->binning_horizontal;
+ else
+ vt_op_binning_div = 1;
+ dev_dbg(dev, "vt_op_binning_div: %d\n", vt_op_binning_div);
+
+ /*
+ * Profile 2 supports vt_pix_clk_div E [4, 10]
+ *
+ * Horizontal binning can be used as a base for difference in
+ * divisors. One must make sure that horizontal blanking is
+ * enough to accommodate the CSI-2 sync codes.
+ *
+ * Take scaling factor into account as well.
+ *
+ * Find absolute limits for the factor of vt divider.
+ */
+ dev_dbg(dev, "scale_m: %d\n", pll->scale_m);
+ min_vt_div = DIV_ROUND_UP(pll->op_pix_clk_div * pll->op_sys_clk_div
+ * pll->scale_n,
+ lane_op_clock_ratio * vt_op_binning_div
+ * pll->scale_m);
+
+ /* Find smallest and biggest allowed vt divisor. */
+ dev_dbg(dev, "min_vt_div: %d\n", min_vt_div);
+ min_vt_div = max(min_vt_div,
+ DIV_ROUND_UP(pll->pll_op_clk_freq_hz,
+ limits->max_vt_pix_clk_freq_hz));
+ dev_dbg(dev, "min_vt_div: max_vt_pix_clk_freq_hz: %d\n",
+ min_vt_div);
+ min_vt_div = max_t(uint32_t, min_vt_div,
+ limits->min_vt_pix_clk_div
+ * limits->min_vt_sys_clk_div);
+ dev_dbg(dev, "min_vt_div: min_vt_clk_div: %d\n", min_vt_div);
+
+ max_vt_div = limits->max_vt_sys_clk_div * limits->max_vt_pix_clk_div;
+ dev_dbg(dev, "max_vt_div: %d\n", max_vt_div);
+ max_vt_div = min(max_vt_div,
+ DIV_ROUND_UP(pll->pll_op_clk_freq_hz,
+ limits->min_vt_pix_clk_freq_hz));
+ dev_dbg(dev, "max_vt_div: min_vt_pix_clk_freq_hz: %d\n",
+ max_vt_div);
+
+ /*
+ * Find limitsits for sys_clk_div. Not all values are possible
+ * with all values of pix_clk_div.
+ */
+ min_sys_div = limits->min_vt_sys_clk_div;
+ dev_dbg(dev, "min_sys_div: %d\n", min_sys_div);
+ min_sys_div = max(min_sys_div,
+ DIV_ROUND_UP(min_vt_div,
+ limits->max_vt_pix_clk_div));
+ dev_dbg(dev, "min_sys_div: max_vt_pix_clk_div: %d\n", min_sys_div);
+ min_sys_div = max(min_sys_div,
+ pll->pll_op_clk_freq_hz
+ / limits->max_vt_sys_clk_freq_hz);
+ dev_dbg(dev, "min_sys_div: max_pll_op_clk_freq_hz: %d\n", min_sys_div);
+ min_sys_div = clk_div_even_up(min_sys_div);
+ dev_dbg(dev, "min_sys_div: one or even: %d\n", min_sys_div);
+
+ max_sys_div = limits->max_vt_sys_clk_div;
+ dev_dbg(dev, "max_sys_div: %d\n", max_sys_div);
+ max_sys_div = min(max_sys_div,
+ DIV_ROUND_UP(max_vt_div,
+ limits->min_vt_pix_clk_div));
+ dev_dbg(dev, "max_sys_div: min_vt_pix_clk_div: %d\n", max_sys_div);
+ max_sys_div = min(max_sys_div,
+ DIV_ROUND_UP(pll->pll_op_clk_freq_hz,
+ limits->min_vt_pix_clk_freq_hz));
+ dev_dbg(dev, "max_sys_div: min_vt_pix_clk_freq_hz: %d\n", max_sys_div);
+
+ /*
+ * Find pix_div such that a legal pix_div * sys_div results
+ * into a value which is not smaller than div, the desired
+ * divisor.
+ */
+ for (vt_div = min_vt_div; vt_div <= max_vt_div;
+ vt_div += 2 - (vt_div & 1)) {
+ for (sys_div = min_sys_div;
+ sys_div <= max_sys_div;
+ sys_div += 2 - (sys_div & 1)) {
+ int pix_div = DIV_ROUND_UP(vt_div, sys_div);
+
+ if (pix_div < limits->min_vt_pix_clk_div
+ || pix_div > limits->max_vt_pix_clk_div) {
+ dev_dbg(dev,
+ "pix_div %d too small or too big (%d--%d)\n",
+ pix_div,
+ limits->min_vt_pix_clk_div,
+ limits->max_vt_pix_clk_div);
+ continue;
+ }
+
+ /* Check if this one is better. */
+ if (pix_div * sys_div
+ <= roundup(min_vt_div, best_pix_div))
+ best_pix_div = pix_div;
+ }
+ if (best_pix_div < INT_MAX >> 1)
+ break;
+ }
+
+ pll->vt_sys_clk_div = DIV_ROUND_UP(min_vt_div, best_pix_div);
+ pll->vt_pix_clk_div = best_pix_div;
+
+ pll->vt_sys_clk_freq_hz =
+ pll->pll_op_clk_freq_hz / pll->vt_sys_clk_div;
+ pll->vt_pix_clk_freq_hz =
+ pll->vt_sys_clk_freq_hz / pll->vt_pix_clk_div;
+
+ pll->pixel_rate_csi =
+ pll->op_pix_clk_freq_hz * lane_op_clock_ratio;
+
+ print_pll(dev, pll);
+
+ rval = bounds_check(dev, pll->pre_pll_clk_div,
+ limits->min_pre_pll_clk_div,
+ limits->max_pre_pll_clk_div, "pre_pll_clk_div");
+ if (!rval)
+ rval = bounds_check(
+ dev, pll->pll_ip_clk_freq_hz,
+ limits->min_pll_ip_freq_hz, limits->max_pll_ip_freq_hz,
+ "pll_ip_clk_freq_hz");
+ if (!rval)
+ rval = bounds_check(
+ dev, pll->pll_multiplier,
+ limits->min_pll_multiplier, limits->max_pll_multiplier,
+ "pll_multiplier");
+ if (!rval)
+ rval = bounds_check(
+ dev, pll->pll_op_clk_freq_hz,
+ limits->min_pll_op_freq_hz, limits->max_pll_op_freq_hz,
+ "pll_op_clk_freq_hz");
+ if (!rval)
+ rval = bounds_check(
+ dev, pll->op_sys_clk_div,
+ limits->min_op_sys_clk_div, limits->max_op_sys_clk_div,
+ "op_sys_clk_div");
+ if (!rval)
+ rval = bounds_check(
+ dev, pll->op_pix_clk_div,
+ limits->min_op_pix_clk_div, limits->max_op_pix_clk_div,
+ "op_pix_clk_div");
+ if (!rval)
+ rval = bounds_check(
+ dev, pll->op_sys_clk_freq_hz,
+ limits->min_op_sys_clk_freq_hz,
+ limits->max_op_sys_clk_freq_hz,
+ "op_sys_clk_freq_hz");
+ if (!rval)
+ rval = bounds_check(
+ dev, pll->op_pix_clk_freq_hz,
+ limits->min_op_pix_clk_freq_hz,
+ limits->max_op_pix_clk_freq_hz,
+ "op_pix_clk_freq_hz");
+ if (!rval)
+ rval = bounds_check(
+ dev, pll->vt_sys_clk_freq_hz,
+ limits->min_vt_sys_clk_freq_hz,
+ limits->max_vt_sys_clk_freq_hz,
+ "vt_sys_clk_freq_hz");
+ if (!rval)
+ rval = bounds_check(
+ dev, pll->vt_pix_clk_freq_hz,
+ limits->min_vt_pix_clk_freq_hz,
+ limits->max_vt_pix_clk_freq_hz,
+ "vt_pix_clk_freq_hz");
+
+ return rval;
+}
+EXPORT_SYMBOL_GPL(smiapp_pll_calculate);
+
+MODULE_AUTHOR("Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>");
+MODULE_DESCRIPTION("Generic SMIA/SMIA++ PLL calculator");
+MODULE_LICENSE("GPL");
--- /dev/null
+/*
+ * drivers/media/video/smiapp-pll.h
+ *
+ * Generic driver for SMIA/SMIA++ compliant camera modules
+ *
+ * Copyright (C) 2012 Nokia Corporation
+ * Contact: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#ifndef SMIAPP_PLL_H
+#define SMIAPP_PLL_H
+
+#include <linux/device.h>
+
+struct smiapp_pll {
+ uint8_t lanes;
+ uint8_t binning_horizontal;
+ uint8_t binning_vertical;
+ uint8_t scale_m;
+ uint8_t scale_n;
+ uint8_t bits_per_pixel;
+ uint16_t flags;
+ uint32_t link_freq;
+
+ uint16_t pre_pll_clk_div;
+ uint16_t pll_multiplier;
+ uint16_t op_sys_clk_div;
+ uint16_t op_pix_clk_div;
+ uint16_t vt_sys_clk_div;
+ uint16_t vt_pix_clk_div;
+
+ uint32_t ext_clk_freq_hz;
+ uint32_t pll_ip_clk_freq_hz;
+ uint32_t pll_op_clk_freq_hz;
+ uint32_t op_sys_clk_freq_hz;
+ uint32_t op_pix_clk_freq_hz;
+ uint32_t vt_sys_clk_freq_hz;
+ uint32_t vt_pix_clk_freq_hz;
+
+ uint32_t pixel_rate_csi;
+};
+
+struct smiapp_pll_limits {
+ /* Strict PLL limits */
+ uint32_t min_ext_clk_freq_hz;
+ uint32_t max_ext_clk_freq_hz;
+ uint16_t min_pre_pll_clk_div;
+ uint16_t max_pre_pll_clk_div;
+ uint32_t min_pll_ip_freq_hz;
+ uint32_t max_pll_ip_freq_hz;
+ uint16_t min_pll_multiplier;
+ uint16_t max_pll_multiplier;
+ uint32_t min_pll_op_freq_hz;
+ uint32_t max_pll_op_freq_hz;
+
+ uint16_t min_vt_sys_clk_div;
+ uint16_t max_vt_sys_clk_div;
+ uint32_t min_vt_sys_clk_freq_hz;
+ uint32_t max_vt_sys_clk_freq_hz;
+ uint16_t min_vt_pix_clk_div;
+ uint16_t max_vt_pix_clk_div;
+ uint32_t min_vt_pix_clk_freq_hz;
+ uint32_t max_vt_pix_clk_freq_hz;
+
+ uint16_t min_op_sys_clk_div;
+ uint16_t max_op_sys_clk_div;
+ uint32_t min_op_sys_clk_freq_hz;
+ uint32_t max_op_sys_clk_freq_hz;
+ uint16_t min_op_pix_clk_div;
+ uint16_t max_op_pix_clk_div;
+ uint32_t min_op_pix_clk_freq_hz;
+ uint32_t max_op_pix_clk_freq_hz;
+
+ /* Other relevant limits */
+ uint32_t min_line_length_pck_bin;
+ uint32_t min_line_length_pck;
+};
+
+/* op pix clock is for all lanes in total normally */
+#define SMIAPP_PLL_FLAG_OP_PIX_CLOCK_PER_LANE (1 << 0)
+#define SMIAPP_PLL_FLAG_NO_OP_CLOCKS (1 << 1)
+
+struct device;
+
+int smiapp_pll_calculate(struct device *dev, struct smiapp_pll_limits *limits,
+ struct smiapp_pll *pll);
+
+#endif /* SMIAPP_PLL_H */
projects / openwrt / staging / blogic.git / commitdiff