#endif /* CONFIG_PPC_MPC52xx */
#ifdef CONFIG_PPC_MPC512x
-struct mpc512x_clockctl {
- u32 spmr; /* System PLL Mode Reg */
- u32 sccr[2]; /* System Clk Ctrl Reg 1 & 2 */
- u32 scfr1; /* System Clk Freq Reg 1 */
- u32 scfr2; /* System Clk Freq Reg 2 */
- u32 reserved;
- u32 bcr; /* Bread Crumb Reg */
- u32 pccr[12]; /* PSC Clk Ctrl Reg 0-11 */
- u32 spccr; /* SPDIF Clk Ctrl Reg */
- u32 cccr; /* CFM Clk Ctrl Reg */
- u32 dccr; /* DIU Clk Cnfg Reg */
- u32 mccr[4]; /* MSCAN Clk Ctrl Reg 1-3 */
-};
-
-static struct of_device_id mpc512x_clock_ids[] = {
- { .compatible = "fsl,mpc5121-clock", },
- {}
-};
-
static u32 mpc512x_can_get_clock(struct platform_device *ofdev,
- const char *clock_name, int *mscan_clksrc)
+ const char *clock_source, int *mscan_clksrc)
{
- struct mpc512x_clockctl __iomem *clockctl;
- struct device_node *np_clock;
- struct clk *sys_clk, *ref_clk;
- int plen, clockidx, clocksrc = -1;
- u32 sys_freq, val, clockdiv = 1, freq = 0;
- const u32 *pval;
-
- np_clock = of_find_matching_node(NULL, mpc512x_clock_ids);
- if (!np_clock) {
- dev_err(&ofdev->dev, "couldn't find clock node\n");
- return 0;
- }
- clockctl = of_iomap(np_clock, 0);
- if (!clockctl) {
- dev_err(&ofdev->dev, "couldn't map clock registers\n");
- goto exit_put;
- }
+ struct device_node *np;
+ u32 clockdiv;
+ enum {
+ CLK_FROM_AUTO,
+ CLK_FROM_IPS,
+ CLK_FROM_SYS,
+ CLK_FROM_REF,
+ } clk_from;
+ struct clk *clk_in, *clk_can;
+ unsigned long freq_calc;
+ struct mscan_priv *priv;
+ struct clk *clk_ipg;
- /* Determine the MSCAN device index from the peripheral's
- * physical address. Register address offsets against the
- * IMMR base are: 0x1300, 0x1380, 0x2300, 0x2380
+ /* the caller passed in the clock source spec that was read from
+ * the device tree, get the optional clock divider as well
*/
- pval = of_get_property(ofdev->dev.of_node, "reg", &plen);
- BUG_ON(!pval || plen < sizeof(*pval));
- clockidx = (*pval & 0x80) ? 1 : 0;
- if (*pval & 0x2000)
- clockidx += 2;
+ np = ofdev->dev.of_node;
+ clockdiv = 1;
+ of_property_read_u32(np, "fsl,mscan-clock-divider", &clockdiv);
+ dev_dbg(&ofdev->dev, "device tree specs: clk src[%s] div[%d]\n",
+ clock_source ? clock_source : "<NULL>", clockdiv);
+
+ /* when clock-source is 'ip', the CANCTL1[CLKSRC] bit needs to
+ * get set, and the 'ips' clock is the input to the MSCAN
+ * component
+ *
+ * for clock-source values of 'ref' or 'sys' the CANCTL1[CLKSRC]
+ * bit needs to get cleared, an optional clock-divider may have
+ * been specified (the default value is 1), the appropriate
+ * MSCAN related MCLK is the input to the MSCAN component
+ *
+ * in the absence of a clock-source spec, first an optimal clock
+ * gets determined based on the 'sys' clock, if that fails the
+ * 'ref' clock is used
+ */
+ clk_from = CLK_FROM_AUTO;
+ if (clock_source) {
+ /* interpret the device tree's spec for the clock source */
+ if (!strcmp(clock_source, "ip"))
+ clk_from = CLK_FROM_IPS;
+ else if (!strcmp(clock_source, "sys"))
+ clk_from = CLK_FROM_SYS;
+ else if (!strcmp(clock_source, "ref"))
+ clk_from = CLK_FROM_REF;
+ else
+ goto err_invalid;
+ dev_dbg(&ofdev->dev, "got a clk source spec[%d]\n", clk_from);
+ }
+ if (clk_from == CLK_FROM_AUTO) {
+ /* no spec so far, try the 'sys' clock; round to the
+ * next MHz and see if we can get a multiple of 16MHz
+ */
+ dev_dbg(&ofdev->dev, "no clk source spec, trying SYS\n");
+ clk_in = devm_clk_get(&ofdev->dev, "sys");
+ if (IS_ERR(clk_in))
+ goto err_notavail;
+ freq_calc = clk_get_rate(clk_in);
+ freq_calc += 499999;
+ freq_calc /= 1000000;
+ freq_calc *= 1000000;
+ if ((freq_calc % 16000000) == 0) {
+ clk_from = CLK_FROM_SYS;
+ clockdiv = freq_calc / 16000000;
+ dev_dbg(&ofdev->dev,
+ "clk fit, sys[%lu] div[%d] freq[%lu]\n",
+ freq_calc, clockdiv, freq_calc / clockdiv);
+ }
+ }
+ if (clk_from == CLK_FROM_AUTO) {
+ /* no spec so far, use the 'ref' clock */
+ dev_dbg(&ofdev->dev, "no clk source spec, trying REF\n");
+ clk_in = devm_clk_get(&ofdev->dev, "ref");
+ if (IS_ERR(clk_in))
+ goto err_notavail;
+ clk_from = CLK_FROM_REF;
+ freq_calc = clk_get_rate(clk_in);
+ dev_dbg(&ofdev->dev,
+ "clk fit, ref[%lu] (no div) freq[%lu]\n",
+ freq_calc, freq_calc);
+ }
- /*
- * Clock source and divider selection: 3 different clock sources
- * can be selected: "ip", "ref" or "sys". For the latter two, a
- * clock divider can be defined as well. If the clock source is
- * not specified by the device tree, we first try to find an
- * optimal CAN source clock based on the system clock. If that
- * is not posslible, the reference clock will be used.
+ /* select IPS or MCLK as the MSCAN input (returned to the caller),
+ * setup the MCLK mux source and rate if applicable, apply the
+ * optionally specified or derived above divider, and determine
+ * the actual resulting clock rate to return to the caller
*/
- if (clock_name && !strcmp(clock_name, "ip")) {
+ switch (clk_from) {
+ case CLK_FROM_IPS:
+ clk_can = devm_clk_get(&ofdev->dev, "ips");
+ if (IS_ERR(clk_can))
+ goto err_notavail;
+ priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
+ priv->clk_can = clk_can;
+ freq_calc = clk_get_rate(clk_can);
*mscan_clksrc = MSCAN_CLKSRC_IPS;
- freq = mpc5xxx_get_bus_frequency(ofdev->dev.of_node);
- } else {
+ dev_dbg(&ofdev->dev, "clk from IPS, clksrc[%d] freq[%lu]\n",
+ *mscan_clksrc, freq_calc);
+ break;
+ case CLK_FROM_SYS:
+ case CLK_FROM_REF:
+ clk_can = devm_clk_get(&ofdev->dev, "mclk");
+ if (IS_ERR(clk_can))
+ goto err_notavail;
+ priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
+ priv->clk_can = clk_can;
+ if (clk_from == CLK_FROM_SYS)
+ clk_in = devm_clk_get(&ofdev->dev, "sys");
+ if (clk_from == CLK_FROM_REF)
+ clk_in = devm_clk_get(&ofdev->dev, "ref");
+ if (IS_ERR(clk_in))
+ goto err_notavail;
+ clk_set_parent(clk_can, clk_in);
+ freq_calc = clk_get_rate(clk_in);
+ freq_calc /= clockdiv;
+ clk_set_rate(clk_can, freq_calc);
+ freq_calc = clk_get_rate(clk_can);
*mscan_clksrc = MSCAN_CLKSRC_BUS;
-
- pval = of_get_property(ofdev->dev.of_node,
- "fsl,mscan-clock-divider", &plen);
- if (pval && plen == sizeof(*pval))
- clockdiv = *pval;
- if (!clockdiv)
- clockdiv = 1;
-
- if (!clock_name || !strcmp(clock_name, "sys")) {
- sys_clk = devm_clk_get(&ofdev->dev, "sys_clk");
- if (IS_ERR(sys_clk)) {
- dev_err(&ofdev->dev, "couldn't get sys_clk\n");
- goto exit_unmap;
- }
- /* Get and round up/down sys clock rate */
- sys_freq = 1000000 *
- ((clk_get_rate(sys_clk) + 499999) / 1000000);
-
- if (!clock_name) {
- /* A multiple of 16 MHz would be optimal */
- if ((sys_freq % 16000000) == 0) {
- clocksrc = 0;
- clockdiv = sys_freq / 16000000;
- freq = sys_freq / clockdiv;
- }
- } else {
- clocksrc = 0;
- freq = sys_freq / clockdiv;
- }
- }
-
- if (clocksrc < 0) {
- ref_clk = devm_clk_get(&ofdev->dev, "ref_clk");
- if (IS_ERR(ref_clk)) {
- dev_err(&ofdev->dev, "couldn't get ref_clk\n");
- goto exit_unmap;
- }
- clocksrc = 1;
- freq = clk_get_rate(ref_clk) / clockdiv;
- }
+ dev_dbg(&ofdev->dev, "clk from MCLK, clksrc[%d] freq[%lu]\n",
+ *mscan_clksrc, freq_calc);
+ break;
+ default:
+ goto err_invalid;
}
- /* Disable clock */
- out_be32(&clockctl->mccr[clockidx], 0x0);
- if (clocksrc >= 0) {
- /* Set source and divider */
- val = (clocksrc << 14) | ((clockdiv - 1) << 17);
- out_be32(&clockctl->mccr[clockidx], val);
- /* Enable clock */
- out_be32(&clockctl->mccr[clockidx], val | 0x10000);
- }
+ /* the above clk_can item is used for the bitrate, access to
+ * the peripheral's register set needs the clk_ipg item
+ */
+ clk_ipg = devm_clk_get(&ofdev->dev, "ipg");
+ if (IS_ERR(clk_ipg))
+ goto err_notavail_ipg;
+ if (clk_prepare_enable(clk_ipg))
+ goto err_notavail_ipg;
+ priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
+ priv->clk_ipg = clk_ipg;
+
+ /* return the determined clock source rate */
+ return freq_calc;
+
+err_invalid:
+ dev_err(&ofdev->dev, "invalid clock source specification\n");
+ /* clock source rate could not get determined */
+ return 0;
- /* Enable MSCAN clock domain */
- val = in_be32(&clockctl->sccr[1]);
- if (!(val & (1 << 25)))
- out_be32(&clockctl->sccr[1], val | (1 << 25));
+err_notavail:
+ dev_err(&ofdev->dev, "cannot acquire or setup bitrate clock source\n");
+ /* clock source rate could not get determined */
+ return 0;
- dev_dbg(&ofdev->dev, "using '%s' with frequency divider %d\n",
- *mscan_clksrc == MSCAN_CLKSRC_IPS ? "ips_clk" :
- clocksrc == 1 ? "ref_clk" : "sys_clk", clockdiv);
+err_notavail_ipg:
+ dev_err(&ofdev->dev, "cannot acquire or setup register clock\n");
+ /* clock source rate could not get determined */
+ return 0;
+}
-exit_unmap:
- iounmap(clockctl);
-exit_put:
- of_node_put(np_clock);
- return freq;
+static void mpc512x_can_put_clock(struct platform_device *ofdev)
+{
+ struct mscan_priv *priv;
+
+ priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
+ if (priv->clk_ipg)
+ clk_disable_unprepare(priv->clk_ipg);
}
#else /* !CONFIG_PPC_MPC512x */
static u32 mpc512x_can_get_clock(struct platform_device *ofdev,
{
return 0;
}
+#define mpc512x_can_put_clock NULL
#endif /* CONFIG_PPC_MPC512x */
static const struct of_device_id mpc5xxx_can_table[];
static const struct mpc5xxx_can_data mpc5200_can_data = {
.type = MSCAN_TYPE_MPC5200,
.get_clock = mpc52xx_can_get_clock,
+ /* .put_clock not applicable */
};
static const struct mpc5xxx_can_data mpc5121_can_data = {
.type = MSCAN_TYPE_MPC5121,
.get_clock = mpc512x_can_get_clock,
+ .put_clock = mpc512x_can_put_clock,
};
static const struct of_device_id mpc5xxx_can_table[] = {
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