};
/*
- * The UART1/2 functional clock acts as the functional
- * clock for UART4. No separate fclk control available.
+ * The UART1/2 functional clock acts as the functional clock for
+ * UART4. No separate fclk control available. XXX Well now we have a
+ * uart4_fck that is apparently used as the UART4 functional clock,
+ * but it also seems that uart1_fck or uart2_fck are still needed, at
+ * least for UART4 softresets to complete. This really needs
+ * clarification.
*/
static struct clk uart4_ick_am35xx = {
.name = "uart4_ick",
{ .dma_req = -1 }
};
+/*
+ * XXX AM35xx UART4 cannot complete its softreset without uart1_fck or
+ * uart2_fck being enabled. So we add uart1_fck as an optional clock,
+ * below, and set the HWMOD_CONTROL_OPT_CLKS_IN_RESET. This really
+ * should not be needed. The functional clock structure of the AM35xx
+ * UART4 is extremely unclear and opaque; it is unclear what the role
+ * of uart1/2_fck is for the UART4. Any clarification from either
+ * empirical testing or the AM3505/3517 hardware designers would be
+ * most welcome.
+ */
+static struct omap_hwmod_opt_clk am35xx_uart4_opt_clks[] = {
+ { .role = "softreset_uart1_fck", .clk = "uart1_fck" },
+};
+
static struct omap_hwmod am35xx_uart4_hwmod = {
.name = "uart4",
.mpu_irqs = am35xx_uart4_mpu_irqs,
.idlest_idle_bit = AM35XX_ST_UART4_SHIFT,
},
},
+ .opt_clks = am35xx_uart4_opt_clks,
+ .opt_clks_cnt = ARRAY_SIZE(am35xx_uart4_opt_clks),
+ .flags = HWMOD_CONTROL_OPT_CLKS_IN_RESET,
.class = &omap2_uart_class,
};